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1
Dulal, Prabin. "Optoelectronic Characteristics of Indium Oxide Thin Films." Bowling Green State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1562680154150056.
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Royo, Romero Luis. "Optoelectronic Characteristics of Inorganic Nanocrystals and Their Solids." Bowling Green State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1555422820907262.
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Драч, Юрій Олександрович. "Підвищення точності вимірювання геометричних розмірів мікрометричного діапазону шляхом вдосконалення вузла освітлення оптико-електронної системи." Master's thesis, КПІ ім. Ігоря Сікорського, 2020. https://ela.kpi.ua/handle/123456789/38419.
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В даній магістерській дисертаційній роботі проведено аналітичне
дослідження будови оптико-електронної вимірювальної системи, її складових
вузлів та особливостей налаштування. З самої теми дисертації «Підвищення
точності вимірювання геометричних розмірів мікрометричного діапазону
шляхом вдосконалення вузла освітлення оптико-електронної системи» видно,
що шляхом підвищення точності вимірювання геометричних розмірів у
мікрометричному діапазону є вдосконалення джерела освітлення.
Ми визначили основні відомі методи визначення світло-технічних
характеристик джерел освітлення у другому розділі дисертації. В розділі нами
проаналізовано методи «інтегруючої сфери» та «гоніофотометричний» для
визначення світлового потоку освітлювальних систем з різним типом
світлового розподілу. Звісно, ми розглядали методи світового досвіду
визначення цих характеристик та вітчизняного досвіду, адже ми планували
проведення експериментальних досліджень власного джерела
випромінювання, що відповідало б світовому рівню.
У третьому розділі ми навели приклади трьох джерел освітлення з
зазначенням світлотехнічних характеристик. Ми зазначили спектральні
характеристики для кожного джерела освітлення.
У четвертому розділі ми навели матеріали, щодо побудови нами оптико-
електронної вимірювальної системи. Свою вимірювальну систему для
визначення геометричних розмірів мікрометричного діапазону, ми
спроектували на базі оптичного мікроскопу, телевізійної камери, що
закріплювалась до тіла оптичного мікроскопу з застосуванням перехідників
(тубусів). Отримане, CCD матрицею телевізійної камери, випромінювання від
об’єкту дослідження геометричних розмірів, надходило до персонального
комп’ютеру з необхідним програмним забезпеченням, що дозволило нам за
випромінюванням визначати розміри об’єкту або дефекту об’єкту. Хочемо
зазначити, що програмне забезпечення ми в магістерській дисертації не
розробляли, а користувались готовим програмним продуктом. Адже такого
завдання перед нами не стояло. Більшість наших зусиль було спрямовано на
дослідження джерела освітлення. Проте, хочемо зазначити, що після
отриманих результатів щодо дослідження світло-технічних характеристик
нового джерела освітлення, ми провели ряд вимірювань геометричних
розмірів у мікрометричному діапазоні. Щоб порівняти точність вимірювання
мікрометричних геометричних розмірів. Для цього ми проводили
вимірювання на еталонному зразку лінійних геометричних розмірів ГОСТ
15114-78 Даний комплект мір використовують встановлення роздільної
здатності телескопічних систем, кутові геометричні розміри ми не
вимірювали.
Хочемо зазначити, що ми обрали у якості нового джерела освітлення
світлодіодну лампу та порівнювали отримані результати світлотехнічних
характеристик з джерелом, що є стандартним (базовим) для моделі оптичного
мікроскопу. Отже нами проведено ряд експериментальних досліджень
світлотехнічних характеристик найпопулярнішого джерела освітлення -
світлодіодної ламп. Аналіз результатів дослідження показав, що перед тим як
застосовувати лампу масового виробництва виготовлену за будь-якою
технологією у вимірювальній системі (оптико-електронна система) необхідно
після спеціалізованого дослідження у центрах випробувань і діагностики
надпровідникових джерел світла та освітлювальних систем. Адже зазначені
світлотехнічні характеристики від виробників не відповідають тим, що
визначено дослідним шляхом.In this master's dissertation an analytical study of the structure of the optoelectronic measuring system, its components and features of the setting. From the topic of the dissertation "Improving the accuracy of measuring the geometric dimensions of the micrometric range by improving the lighting unit of the optoelectronic system" it is clear that by improving the accuracy of measuring geometric dimensions in the micrometric range is improving the light source. We have identified the main known methods for determining the lighting characteristics of light sources in the second section of the dissertation. In this section we analyze the methods of "integrating sphere" and "goniophometric" to determine the luminous flux of lighting systems with different types of light distribution. Of course, we considered the methods of world experience in determining these characteristics and domestic experience, because we planned to conduct experimental studies of our own radiation source, which would correspond to the world level. In the third section, we gave examples of three light sources with lighting characteristics. We noted the spectral characteristics for each light source. In the fourth section, we presented materials on the construction of our optoelectronic measuring system. We designed our measuring system to determine the geometric dimensions of the micrometric range on the basis of an optical microscope, a television camera, which was attached to the body of the optical microscope using adapters (tubes). The radiation received from the geometric dimensions object by the CCD matrix of the television camera was sent to a personal computer with the necessary software, which allowed us to determine the dimensions of the object or the defect of the object by the radiation. We would like to note that we did not develop the software in the master's dissertation, but used the finished software product. After all, we did not face such a task. Most of our efforts have been focused on researching the light source. However, we would like to note that after the results obtained on the study of lighting characteristics of the new light source, we conducted a series of measurements of geometric dimensions in the micrometric range. To compare the accuracy of measuring micrometric geometric dimensions. To do this, we performed measurements on a reference sample of linear geometric dimensions GOST 15114-78 This set of measures uses the establishment of the resolution of telescopic systems, we did not measure the angular geometric dimensions. We would like to note that we chose an LED lamp as a new light source and compared the obtained results of lighting characteristics with a source that is standard (basic) for the optical microscope model. Therefore, we conducted a number of experimental studies of the lighting characteristics of the most popular light source - LED lamps. Analysis of the results of the study showed that before using a mass-produced lamp made by any technology in a measuring system (optoelectronic system) it is necessary after a specialized study in the centers of testing and diagnostics of superconducting light sources and lighting systems. After all, these lighting characteristics from the manufacturers do not correspond to those determined experimentally. Although the characteristics of the LED lamp were not significantly different from the halogen lamp. The impact on the measurement accuracy of the optoelectronic measuring system of these light sources, we determined using a bar measure of absolute contrast and concluded that the efficiency of LED lighting is four times higher than halogen lighting when building a measuring system as described in dissertation.
4
Al-Ramli, I. F. K. "Receiver structures and filter characteristics for M-ary optical communication systems." Thesis, University of Essex, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356042.
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Микитенко, Володимир Іванович. "Підвищення ефективності функціонування оптико-електронних систем спостереження з комплексуванням зображень." Thesis, КПІ ім. Ігоря Сікорського, 2020. https://ela.kpi.ua/handle/123456789/31476.
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Дисертаційну роботу присвячено вирішенню важливої наукової проблеми підвищення ефективності функціонування багатоканальних оптико-електронних систем спостереження з комплексуванням зображень шляхом створення методів узгодження характеристик основних блоків, механізму оцінювання ефективності функціонування систем і адаптивного вибору найкращого методу злиття зображень спектральних каналів, засобів експериментального визначення основних характеристик систем, що дозволяє покращити якість виконання поточної задачі спостереження оператором, підвищити максимальну дальність виявлення об’єктів в двоканальних системах до 12%, забезпечує збільшення динамічного діапазону вимірювання енергетичних характеристик до 2,5 разів.The dissertation is devoted to solving the scientific problem of increasing performance of optoelectronic surveillance systems (OESS) with image fusion by creating scientific bases and applied methods of analysis, synthesis and adjustment of information channels on a uniform methodological basis. The methodological bases for improving the OESS power consumption with image fusion are scientifically substantiated. They include the methods of constructive harmonization of the OESS’s main units characteristics, the mechanism of the adaptive selection of the best method of spectral images merging, the means of experimental determination of the OESS main characteristics and allow increase performance of the system. By information fusion from different channels, one can dramatically improve the quality of background status (BS) information. There is still no unified OESS design technology to analyze and synthesize the entire information system, to formulate technical requirements for individual blocks of spectral channels and algorithms for image fusion, taking into account the context of the observer's current task and type of BS. A number of problems remain to be solved with regard to improve the OESS performance by forming the image in operator’s field of view, which content provides best solution to the current surveillance task. An «object - OESS with image fusion – operator» mathematical model has been created. It allows analyze and design the OESS within a linear model. The formula for mod-ulation transfer function of the “lens - detector” system of the aerospace OESS was obtained at arbitrary angles of view. It can be used to calculate the values of the lens pupil diameter, focal length of the lens and threshold irradiance of detector, which is required to achieve the given image contrast. Unified algorithm for estimation of spatial and energy properties of OESS spectral channels based on the targeting task performance (TTP) metric is offered. It allows to determine the main information channel in the OESS as the base for further fusion, as well as to coordinate the parameters of the input blocks of two-chan-nel OESS. The method of performance estimation of OESS with information fusion on the basis of a posteriori TTP metric is developed. The metric is determined numerically for the method of merging images on the resulting spatial spectrum of images. This method allows to investigate the features of the image fusion process and its visual perception by the operator. It allows you to calculate the probability of detection, recognition and identification of an object, which is observed by the OESS with image fusion. A new method of reconciling the basic parameters of monoblock collimator and telescopic sights for small arms is proposed. Two variants of monoblock collimator sights with improved aiming accuracy are offered. The sight of two optical parts with different refractive index, glued on the plane, provides a linear aperture of the original pupil of the sight 0.276, with parallax 3 mrad. A monoblock collimator sight of two optical parts with different refractive index, glued on a spherical surface, at the same linear aperture of the original pupil and mass provides parallax of 1.25 mrad. A scheme of a decentralized tele-scopic monoblock is proposed, in which at a mismatch of 3 mrad the magnification can reach 1.6 times compared to 1.4 times for an axisymmetric scheme. A new method for measuring OESS spectral channels basic energy characteristics has been developed. This method, compared to its analogues, increases the dynamic range up to 2.5 times with a high uniformity of the brightness field. For the first time, the efficiency of the image fusion strategy, which allows to increase the maximum detection range of objects in dual-channel OESS by up to 12%, was developed and experimentally validated. New methods of increasing the speed of information processing in multichannel OESS with image fusion are proposed. The first method uses the information map based on the low spatial resolution channel and the second method uses a digital coherent optical processor. The amount of computation in the first case can be reduced up to 2 times.
Диссертационная работа посвящена решению важной научной проблемы повышения эффективности функционирования многоканальных оптико-электронных систем наблюдения с комплексированием изображений путем создания методов согласования характеристик основных блоков, механизма оценки эффективности функционирования систем и адаптивного выбора наилучшего метода слияния изображений спектральных каналов, средств экспериментального определения основных характеристик систем, что позволяет улучшить качество выполнения текущей задачи наблюдения оператором, повысить максимальную дальность обнаружения объектов в двухканальных системах до 12%, обеспечивает увеличение динамического диапазона измерения энергетических характеристик до 2,5 раз.
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Haidar, Jihad. "Commande optoélectronique d'atténuateurs, de résonateurs et de filtres microondes réalises sur substrat silicium." Grenoble INPG, 1996. http://www.theses.fr/1996INPG0094.
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La commande optique de dispositifs microondes, qui exploite l'injection optique des porteurs dans un semiconducteur, apporte de nombreux avantages vis-a-vis de l'electronique conventionnelle. La presente etude avait pour objectif d'etendre cette commande a des dispositifs, realisant des fonctions complexes, tels que les attenuateurs, resonateurs et filtres microondes. Les structures etudiees ont ete realisees sur du silicium en technologie ligne microruban. Nous avons exploite principalement la charge complexe induite entre le ruban et le plan de masse par illumination optique. Nous avons demontre que la lumiere cree principalement une charge resistive aux faibles puissances, mais qu'une composante reactive apparait aussi d'une maniere nette pour les puissances optiques elevees. L'effet resistif a ete mis en application dans la realisation d'un attenuateur microondes en technologie microruban, reglable par la simple commande optique. Nous avons demontre sur un premier prototype une plage d'attenuation superieure a 10db dans la bande c. Quant a l'effet reactif, nous avons introduit une commande supplementaire qui permet de le renforcer. Il s'agit de polariser le plasma photo-induit par une tension continue qui se superpose au signal hyperfrequences. Nous avons accorde la frequence de differents resonateurs par cette nouvelle double commande optoelectronique. Ces accords, sont, a notre connaissance, de loin les plus larges jamais reportes parmi les accords electriques. En effet, nous avons mesure des deplacements de la frequence de resonance de l'ordre de 30% en dessous de la frequence de resonance en l'absence d'illumination. L'etude est plutot de nature experimentale, mais des modeles theoriques simples ont ete developpes pour tenter d'expliquer les differents phenomenes nouveaux mis en evidence experimentalement. Nous avons reussi a etablir, d'une maniere satisfaisante en premiere approche, le lien entre les parametres physiques du semiconducteur d'une part et le schema equivalent du plasma photo-induit deduit de la reponse microondes du dispositif d'autre part
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LIU, CHIA-CHUAN, and 劉家權. "Optoelectronic Characteristics of Tin Sulfide-Graphene Optoelectronic Device by Chemical Bath Deposition." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/ay549e.
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碩士國立中正大學
光機電整合工程研究所
107
Graphene has a very high carrier mobility and excellent conductivity. It’s very suitable for using as a photodetector. But its transmittance is too high and has poor absorption when it illuminated. The carrier is combined fast after illuminating and the reaction to light is extremely weak. Therefore, a semiconductor material is used to grow on graphene to increase its response to light. For semiconductor materials, tin sulfide will be used. Because tin sulfide has the advantages of stable nature, non-toxicity, low cost and rich content of crust, it has a very high absorption coefficient ( > 1E5) and a suitable energy gap of 1.3 eV. We use chemical bath deposition (CBD) method to deposit tin sulfide on graphene. Due to the high temperature and low pH value of the process environment, the graphene has poor properties. Try to stack two layers of graphene for experiment and Raman spectroscopy and Hall effect measured resistance, carrier mobility and carrier concentration of a layer of graphene and two layers of graphene were measured. In the experiment, it was found that the deposition of one hour, the characteristics of graphene is the best and the characteristics of the element are also excellent. The 405 nm laser, the light intensity is 60 mW, and the switching time is 10 seconds. The rise time, component defect density, responsivity and specific detectivity were 6436 ms, 0.41, 0.046 AW-1 and 5.87E7 Jones.
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Lee, Yu-Chin, and 李昱嶔. "Characteristics of P-type CuGaO2 Optoelectronic Semiconductor." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/83771986340068153857.
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碩士亞洲大學
光電與通訊學系
103
In this study, we prepared CuGaO2 film by using sputtering method and the annealing under controlled nitrogen atmosphere, with the attempt to identify the structure and optoelectronic properties. During the Cu-Ga-O phase change, CuGa2O4 and CuO were the intermediate phases of the reaction for forming CuGaO2, the temperature of CuGaO2 formation is 750°C. CuGaO2 had its structure remaining steady at high temperature, and had its cross-section formed by stacked polygonal microstructure. With the increase of the annealing temperature, the CuGaO2 film had its surface roughness, average grain size and direct band gap increased. The CuGaO2 films had its surface roughness values of 5.70~7.31 nm. The average CuGaO2 grain sizes were 35.59~39.02 nm. When CuGaO2 films were annealed at 750, 800, 850, and 900°C, its direct band gaps were 3.45, 3.50, 3.64, and 3.65eV, respectively. CuGaO2 absorbed mainly the photons with short wavelengths. The CuGaO2 film exhibited transmittance of 68% at a wavelength of 800nm. The positive Hall coefficient proves that the CuGaO2 is a p-type semiconductor.
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Tsai, Chia-Ho, and 蔡佳和. "Optoelectronic Characteristics of GeSn/Ge quantum-well photodetectors." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/xjvpmj.
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碩士國立中正大學
機械工程系研究所
106
GeSn is an emerging group-IV semiconductor material. As the Sn concentration increases, the band gap decreases. When a certain Sn concentration is met, it becomes a direct-band-gap material. Therefore, the band gap of the material can be controlled by adjusting the Sn concentration. Moreover, with the CMOS technology, this study produced a silicon-based photoelectric component. Thus, the potential of GeSn in developing PICs is very high. In the modern world where the communication business is thriving, GeSn can be used to greatly increase information transmission capacity. This study aimed to explore the optoelectronic characteristics of GeSn/Ge quantum-well MSM photodetectors under different temperatures. This study used photolithography to produce GeSn/Ge quantum-well photodetectors with the Sn concentration of 3% and 4%. The optoelectronic characteristics such as responsivity and dark current of the photodetectors were measured under different temperatures. The dark current increased as the temperature increased. Using the Arrhenius equation, the activation energy of the component was extracted. It was found that the activation energy was much smaller than half of the band gap, meaning there were very few component internal defects. The spectrum for the responsivity measurement displayed the feature of the step shape, representing the phenomenon of quantization of energy level, through which we could extract the band gaps of heavy holes (HH) and light holes (LH). The responsivity cut-off wavelength of the component produced by this study was extended to 1700nm, covering the whole telecommunication band. The component can be used for important applications in fiber-optic communication. According to the responsivities measured under different temperatures, as the temperature went up, the redshift of the responsivity can be observed. Although the influence of temperature on band gap was not strong, temperature could still influence the component. In addition, the cut-off wavelength obtained based on responsivity was consistent with the position of the photoluminescence peak, proving that the band gap of the component could be obtained using both methods. Based on the activation energy data, the quantum-well structure was very suitable for GeSn. With this structure, the problem of too many internal defects could be solved.
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Liu, Yuan-yu, and 劉原毓. "Studies of optoelectronic characteristics of optically controlled cholesteric gratings." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/v36nq2.
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碩士國立中山大學
物理學系研究所
96
A optically controlled cholesteric grating is proposed. The dye-doped cholesteric grating (DDCLC grating) can be rotated by changing the polarization of the pump-beam. The experiment results reveal that the orientation of the cholesteric grating can be rotated in a specific range decided by the alignment direction of the two substrates. Moreover, the hybrid alignment condition for the cholesteric grating is also investigated. When the ratio of d/p is larger than 0.5,the cholesteric grating is observable without applying voltage in hybrid aligned cholesteric cell, and the cholesteric gratings with hybrid alignment can have a 360 rotation angle, thus achieve the two dimension beam steering cholesteric.
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Sheng-LungTu and 涂勝龍. "Optoelectronic Characteristics of Nanoscale Ti and TiO2 Thin Films." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/42509194336015712217.
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碩士國立成功大學
機械工程學系碩博士班
98
In this research, the ultrahigh vacuum ion beam sputtering(IBS) system with target oriented in different title angles is used to deposite nano-thin films of different thickness by maintaining the working pressure, working power, working distance, and gas flux constant. When the thickness of Ti thin film is reduced down to the nano-scale, the corresponding resistance would decrease from 10-5 (Ω-m) to 10-6 (Ω-m) When the thickness is less than 50~60 nm, the magnitude of reduction in resistance is more compared with the others, which has a potential to serve as apparent electrodes for applications in optical communications, sensors, and solar cells. Furthermore, the oxygen ambient is maintained during the implementation of IBS process and rapid thermal annealing (RTA) in order to oxidize and convert Ti nano thin film to TiO2 nano thin film for the benefit of peoducing nano scale TiO2 thin film over the surface of the electrode and its optical properties are also studied afterward. Band gap of Anatase phase TiO2 thin film is about 3.2eV. Because of the lattice deformation, the band gap is red-shifted and splitted from one peak into two peaks.
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Chuang, Kuei-Ya, and 莊貴雅. "Study on the optoelectronic characteristics of nano quantum dot." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/37667101689897988501.
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碩士國立中山大學
光電工程研究所
93
The purpose of this thesis is to study the InAs self-organized quantum dots and InAs/GaAsN digital alloys. We have studied the optical properties of these structures after rapid thermal annealing. The measured samples are InGaAs/InAs、InGaAs/InAlAs/InAs、InGaAs/AlAs/InAs quantum dots and InAs/GaAsN short-period superlattice quantum well structures. We have investigated the effect of different strain-reducing layer (SRL) on the photoluminescence (PL) of self-assembled InAs/GaAs quantum dots. From experiments, the coverage layers of Al composition can increase the energy splitting between the ground and first excited states of the quantum dots. It is related to the thickness and composition of the cap layers. Using thick InAlAs and InGaAs together as a SRL results in the energy splitting up to 123meV. However the PL intensity decreases three times. After rapid thermal annealing up to 800°C, the QDs with Al-composed cap layer show no shift of peak wavelength. For InAs/GaAsN digital alloys, through temperature dependent PL spectrum, we can observe PL peak has a blue shift form room temperature to 100K, and a red shift from 100K to 10K. It is similar to the InGaAsN quantum well. However, one of the samples shows temperature insensitive for the PL peaks.
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Yin, Hui-Hsun, and 鄞暉訓. "Characteristics and structure of optoelectronic semiconductor CuAlO2 thin films." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/10277169047788610042.
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碩士亞洲大學
光電與通訊學系碩士班
99
This article reports the structure and optoelectronic properties of p-type CuAlO2 films. The films were prepared through a DC magnetron sputtering process and underwent annealing in controlled Ar atmosphere at 800°C with different holding times. When annealing temperature was 800°C, the formation of the CuAlO2 phase is favored. As the holding time for annealing increased, diffusion of copper, aluminum and oxygen atoms contributed to the phase change and grain growth of CuAlO2. CuO, Al2O3 and CuAl2O4 as metastable intermediates are reduced to nonexistence during the formation of CuAlO2. On the quartz substrate and CuAlO2 film, no interface compound was found as a side product due to the high-temperature annealing. The single-phase CuAlO2 films had a root mean square (RMS) ranging between 3.78 nm and 3.51 nm, with the average grain size of CuAlO2 increased from 25.8 nm to 27.5 nm. The increased grain size lowered the band gap of the CuAlO2 film. Single-phase p-type CuAlO2 films showed lower electrical resistance, as its resistance values exhibited were 231.9 and 242.5 Ωcm, while the band-gap values were 3.33 and 3.26 eV, respectively.
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Wu, Chin-Kun, and 吳錦坤. "The Investigation of Optoelectronic Characteristics with SiGe/Si Heterostructure." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/99506184857317001702.
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碩士大葉大學
電機工程學系
95
In this study, reduction of dark current characteristics in the SiGe-based Metal-Semiconductor-Metal photodetectors (MSM-PD) with and without hydrogenated amorphous silicon (a-Si:H) and/or with silicon dioxide (SiO2) passivation layer will be discussed. The a-Si:H and SiO2 layer were deposited by using plasma-enhanced chemical vapor deposition (PECVD) system. At 6V applied voltage, the measured dark current were 1.27×10-8 A, 2.14×10-3 A and 2.5×10-3 A, respectively, for the samples with a-Si:H passivation, without a-Si:H passivation, and with SiO2 passivation layer, respectively. Compared to the sample without a-Si:H layer, the dark current with a-Si:H passivated one was reduced about five orders. Such a result demonstrates that the a-Si:H exhibits passivation function on SiGe surface. Additionally, we used above result to fabrication a-Si:H/p-SiGe/n-Si heterostructure phototransistor (HPT) having different electrodes (Ni, Ni+ thin Al and ITO). The 850nm infrared laser light source with modulation power was used to irradiate these samples. It was found that the HPT having ITO electrode can achieve high optical- and current-gain.
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詹烱銘. "Optoelectronic characteristics of Indium Tin Oxide and its Multilayer." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/71743473227478667470.
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碩士明新科技大學
化學工程研究所
95
In this thesis, an indium tin oxide (ITO) thin films and multilayer of ITO/Al/ITO were prepared by DC magnetron sputtering methods. Microstructure , resistance, optical properties, and electromagnetic properties of the ITO and ITO/Al/ITO with different growth parameter, and subsequential thermal treatment were studied. We used the optical glass to be the substrate. Direct current (DC) magnetron sputter were used to deposit ITO films and Al films according to the required structure. The report revealed that the 143-nm-thick ITO films with the substrate temperature was at 25 �aC room temperature have high resistivity of 38.99×10-4 Ω-cm by use of plasma power of 90 W. In the region of visible light (400~800nm), the average transmission coefficient is about 87%. The maxium transmittance reaches 98%. The Electro-magnetic shielding effectiveness (MESE) in the region of low frequency (100~400 MHz) can be low as 30 dB, and in the region of high frequency (600~1000 MHz), the EMSE can reach between 20 to 25 dB. With the same plasma power, the resistivity of ITO films are 6.72×10-4 Ω-cm as the substrate temperature is up to 250 �aC. The average transmission coefficient was 88 %. The highest transmittance is about 98 %. The resistivity of ITO films can be further reduced as 3.23×10-4 Ω-cm by ( H2/Ar、500℃、80 min) annealing. The average transmission coefficient was 92 %. The highest transmittance is about 99 %. The EMSE in the region of low frequency is 55 dB. In the same case, the EMSE in high frequency can reach 30~35 dB. After annealing, the quality of crystallinity of ITO film is better according to the results of X-ray diffraction. By use of MaxWell equation, the high conductivity of transparent films can be effective in elevating the EMSE. Al thin films were used to change the preferred orientation of the above ITO films The conductivity in ITO/Al/ITO which prepared at the substrate temperature of 25 �aC. After optimization, the ITO/Al/ITO multilayer films consisting of 85nm/11nm/45nm with a resistivity coefficient of 3.44×10-4 Ω-cm. and the average transmission is about 54 % in the region of visible light. After annealing process ,the average transmission of multilayer with the same resistivity is approximately 92 % in the region of visible light. ITO and ITO/Al/ITO with low resistivity are mete the request of transparent conductive for the application of EMSE. With fine tuning of growth parameter, post-grown annealing, and layer structure, the ITO and ITO/Al/ITO thin films were potential candidates for EMSE.
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Chou, Chi-Yu, and 周錡佑. "Optoelectronic characteristics of Nb:TiO2 films prepared by magnetron sputtering." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/mbj5vj.
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碩士元智大學
光電工程學系
106
This study mainly aimed to use a sputtering system and TNO (Nb:TiO2) ceramic targets to deposit TNO oxide film on high-temperature alkali-free glass. TiO2 doped with Nb, which possesses high refractive index and is indium-free, is considered a new type of transparent conductive film material with good potential. This inspired us to study sputtering of TNO films, whose optical and electrical properties were analyzed. This experiment used the RF magnetron sputtering and TNO ceramic targets to deposit TNO films at different sputtering power levels, working pressures, and substrate temperatures. Test results showed that by heating the substrate to 250°C, the film was transformed from amorphous to crystalline titanium dioxide anatase structures. The film with the lowest resistivity (3.1×10-2Ω-cm) and average visible light transmittance of 51.6%, formed with a sputtering power of 300 W, a reduced working pressure of 0.5 mTorr, and a substrate temperature of 250°C. A high refractive index of 2.57 at a wavelength of 630 nm was achieved.
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Chen, Zheng-hsiung, and 陳政雄. "Studies of characteristics of frequency modulation liquid-crystal optoelectronic devices." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/j2ha3t.
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碩士國立中山大學
物理學系研究所
96
We study the characteristics of the dual frequency liquid-crystal (LC) optoelectronic devices in this literary. We fabricate the LC lens with the dual frequency liquid crystal in our experiment. In this study, we first prepare a parabolic polymer structure on the glass substrate to form a polymeric lens glass, then, fill the dual-frequency LC into the empty cell which consists of one ITO glass and the polymeric lens glass to fabricate a frequency modulation LC lens. Additionally, a hybrid surface alignment is also used for our LC lens. For the dual-frequency LC, a hybrid surface alignment is necessary to obtain a frequency modulation LC lens. Because of the polymeric lens, the electric fields are inhomogeneous distributions in the LC lens when a voltage is applied to the electrodes. In this situation, an inhomogeneous electric field is applied to the cell to create GRIN lens-like distribution of the gradient refractive index. Thus, the focusing effects occur when the light passes through the LC lens. Moreover, by changing the amplitude and frequency of the applied voltage, the focal length of the LC lens can be changed. We mainly discuss the optical property and the response time of the LC lens based on the voltage modulation and the frequency modulation. The experimental results reveal that the frequency modulation has more advantages, such as widen range of controlled focal length and faster response time, comparing with the voltage modulation.
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Yang, HsuYing, and 楊淑英. "Study on the Optoelectronic Characteristics of Amorphous Silicon-Based Photoreceptors." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/68941461883775373167.
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碩士國立雲林科技大學
電子工程與資訊工程技術研究所
87
Due to it's superior photosensitivity in the visible light (650nm ~ 720nm), the hydrogenated amorphous silicon (a-Si:H) material can be widely used on the drum of photoreceptors in copying machines. It contains many excellent properties, such as photosensitivity, thermal stability, mechanical strength and nontoxicity, which are better than traditional photoreceptors. In addition, amorphous tungsten oxide (a-WO3) and n-type hydrogenated amorphous silicon (a-Si:H (n+)) thin films are deposited to be blocking layers, and hydrogenated amorphous carbon (a-C:H) film is deposited to be protect layer. Therefore, the amorphous silicon-based photoreceptor has superior optoelectronic properties and long lifetime. In this study ,we designed and prepared these structures of photoreceptor using the concept of separate function. They are Al/Al2O3/a-Si:H(i), Al/Al2O3/a-WO3/a-Si:H(i), Al/Al2O3/a-Si:H(n+)/a-Si:H(i), and Al/Al2O3/a-Si:H(n+)/a-Si:H(i)/a-C:H. These structures measured with the electrostatic paper analyzer for the photoinduced discharge curve (PIDC) by electrophotography. From our experimental results, the Al/Al2O3/a-Si:H(n+)/a-Si:H(i)/a-C:H structure shows the higher surface potential 540V (36V/mm) , long dark decay time 6 sec, good photosensitivity 8 Lux*sec, residual potential 22V and high contrast voltage ratio 24.5. Besides, the I-V curves of the amorphous silicon-based photoreceptors are measured to investigated the movement of carriers in the photoreceptor at different incident wavelengths and the power of illumination.
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"Optoelectronic characteristics and applications of Helium ion-implanted silicon devices." Thesis, 2007. http://library.cuhk.edu.hk/record=b6074401.
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Finally, we also propose and demonstrate an integrated Mach-Zehnder optical diplexer (IMZOD) for possible use in an integrated silicon optical amplifier. The diplexer is based on two rnultimode interferometers (MMIs) and a Mach-Zehnder interferometer (MZI), and has potential use in an integrated silicon waveguide optical amplifier, to combine or separate the pump signal (1440nm) and probe signal (1556nm) for monolithic implementation of a silicon Raman amplifier.Helium ion implantation can not only reduce the free-carrier loss, but can also enhance the detection responsivity of below-bandgap wavelengths (1440 1590 nm). We propose and demonstrate an in-line channel power monitor (ICPM) based on helium ion implanted silicon waveguides. The implanted waveguide can detect light at 1440 1590 nm which are normally not detectable by silicon. We study the enhanced photoresponse of helium ion implanted waveguide samples which were annealed at different temperatures and for different durations.
Recently there has been much interest in silicon optical amplifiers and lasers relying on stimulated Raman scattering (SRS), which, despite the much shorter waveguide lengths possible in silicon compared with silica optical fiber, can still provide large optical gain because of the large Raman coefficient of silicon and small mode field areas. However, two-photon absorption (TPA) generated free-carrier absorption (FCA) loss can exceed the Raman gain. In this thesis, experiments and theoretical model will he discussed and analyzed, showing that helium ion implantation can successfully reduce the optical losses due to free-carriers and allow net gain to be attained by continuous-wave (CW)-pumped SRS without requiring external bias to remove the photo-generated free carriers. The theoretical study of dynamics of free carrier lifetime of the silicon waveguides will be described. The effective nonlinear length of the silicon waveguides is defined and studied. The theoretical and experimental studies of the enhanced spectral broaden induced by self-phase-modulation (SPM) are carried out in helium on implanted silicon waveguides.
Silicon-on-insulator (SOI) wafers are an attractive platform for the fabrication of planar lightwave circuits (PLCs) because they offer the potential for low-cost fabrication using mature complementary metal--organic--semiconductor (CMOS) compatible processes developed in the microelectronics industry. At the wavelengths of interest for telecommunications, SOI waveguides can have low optical losses (0.1dB/cm). Besides, the strong optical confinement offered by the high index contrast between silicon (Si) (n=3.45) and silicon dioxide (SiO2) (n=1.45) makes it possible to scale photonic devices to sub-micron level. In addition, the high optical intensity arising from the strong optical confinement inside the waveguide makes it possible to observe nonlinear optical effects, such as Raman and Kerr effects, in chip-scale devices.
We then make use of the ICPM to perform a system application, called optical-burst-and-transient-equalizer (OBTE). The OBTE may provide a compact and low-cost solution to compensate gain-transient, gain-spectrum-tilt and to equalize the upstream packet amplitude in erbium doped fiber amplifier (EDFA) amplified hybrid dense-wavelength-division-multiplexed (DWDM) and time-division-multiplexed (TDM) passive-optical-networks (PONs). The OBTE may be monolithically integrated on SOI platform and is potentially low cost and compact. The OBTE can compensate complicated gain slope shape, which may be generated in cascaded EDFAs or deliberate channel add/drop, based on individual channel equalization. 15-dB receiver sensitivity improvement at 10 Gbit/s bit-error-rate (BER) measurements of 10-9 was achieved by the compensation.
Liu, Yang.
"August 2007."
Adviser: Hon Ki Tsang.
Source: Dissertation Abstracts International, Volume: 69-02, Section: B, page: 1212.
Thesis (Ph.D.)--Chinese University of Hong Kong, 2007.
Includes bibliographical references.
Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Abstract in English and Chinese.
School code: 1307.
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Tseng, Chih-ren, and 曾志荏. "Study on the optoelectronic characteristics of ZnO nanowires-based nanoheterojunction." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/56542473417277871702.
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碩士國立成功大學
微電子工程研究所碩博士班
97
In this thesis, the growth and optoelectronic properties of ZnO nanowires-based nanoheterojunction structures are studied. A novel technology using hydrothermal growth (HTG) associated with deposition techniques for the fabrication of nano hetero structure based on ZnO nanowires (ZnO-NWs) is reported in this study. In addition, this study also proposes the use of ZnO-NWs-based nanoheterojunction structures for potential in applications of nano electronic and optoelectronic devices. First, nanoheterojnuction structures were formed via e-beam deposition of p-type nickel oxide (NiO) onto the vertical-aligned ZnO-NWs grown by HTG method. The dark J-V curve shows that the prepared NiO/ZnO-NWs nanoheterojunction structure with 100 nm-thick NiO film has a diode-like behavior with a forward threshold voltage (Vth) of 5.9 V, a leakage current (Jr at -5V) of 0.64 �嫀/cm2, and a good rectification ratio (Iforward/Ireverse at 5 V) of 89, respectively. The experimental optoelectronic characteristics reveals that the one-dimension NiO/ ZnO-NWs nanoheterojunction structures have fairly good sensitivities and fast responses (the rise time and fall time is about 4 and 13 sec, respectively) to UV light with an increase in the photocurrent of about 8�e. Furthermore, in order to improve the optoelectronic properties of the nanoheterojunction structures, the growth of ZnO-NWs with controllable diameter/length/density and fabrication of ZnO-NWs-based nanoheterojunction structures on p-type gallium nitride (p-GaN) are presented. The optoelectronic properties of the ZnO-nanowires/p-GaN nanoheterojunction structures with good UV sensitivities and superior PV performances under an UV light and a simulated AM1.5G solar illumination are reported. Under AM 1.5G solar light illumination, the prepared ZnO-NWs/p-GaN nanoheterojunction structures show superior photovoltaic performances. The short-circuit current, open-circuit voltage, fill factor and power conversion efficiency of the ZnO-nanowires/p-GaN nanoheterojunction structures with 1.2-�慆-long and 100-nm-diameter ZnO-nanowires are 3.43 mA/cm2, 1.7 V, 39.13%, and 2.28%, respectively. It is expected that the functional ZnO-NWs-based nanoheterojunction structures would offer a simple and low-cost building block for high-performance optoelectronics in the future.
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Hung, Ta-Chun, and 洪大鈞. "Preparation and optoelectronic characteristics analysis of Cu2ZnSnS4:O thin films." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/05093977304795966600.
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碩士亞洲大學
光電與通訊學系
102
This study used sol-gel method to prepare Cu2ZnSnS4:O film materials. Correlations between structural and optoelectronic characteristics of the Cu2ZnSnS4:O film were discussed. The Cu2ZnSnS4:O films had a kesterite structure of non-stoichiometric compositions. The oxygen content of 8.89 and 10.30 at.% which changed the microstructure and optoelectronic properties of Cu2ZnSnS4:O materials. With the increase of the oxygen contents, the transmittances of the films become obvious. Direct band gaps of Cu2ZnSnS4:O films were 3.48 and 3.55 eV, respectively. The materials are wide band gap semiconductor. The Cu2ZnSnS4:O films had absorption coefficients of >104cm-1, and resistivities of 19.68 and 5.86 Ωcm.
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Chang, Chia-Hung, and 張家弘. "The optoelectronic characteristics on the InP nanowire field-effect transistors." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/85364552939487000047.
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碩士國立交通大學
電子物理系所
97
Indium phosphide (InP) nanowires with an average diameter of 20 nm were grown for the fabrication of two-probe devices by using the standard electron-beam lithography technique. Current-voltage (I-V) behaviors of the nanowire devices were measured at temperatures from 300℃ down to 120℃. The resistance of the nanowire devices increases with decreasing temperatures, implying the semiconducting behavior in the nanowires. The electron transport as well as the temperature dependent resistance R(T) was calculated. We found that, for the devices having low room-temperature resistance, the R(T) agrees well with the thermal activated transport theory. The low resistance devices might give the intrinsic electrical poperties of the InP nanowires. On the other hand, the high resistance devices could be used to study the electrical properties from the nanocontact. Additionally, the back gate technique was adopted to check the field-effect properties. Electrical characterization on the InP nanowire field-effect transistors indicates that the InP nanowires are natively n-type semiconductors. Moreover, the optoelectronic properties of the two-probe nanowire devices were explored under the exposure of the green light laser (532 nm). We found that the photocurrent, in comparison with the dark current, enhances with a ratio up to 100% for the contact dominated devices while the excited photocurrent is still smaller than that in the nanowire dominated devices.
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Sun, Yun, and 孫耘. "III-V Semiconductor Rolled-up Microtubes and Their Optoelectronic Characteristics." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/06427029470152801089.
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碩士國立交通大學
電子研究所
101
In this thesis semiconductor microtubes formed by thin epilayers grown by Molecular Beam Epitaxy is studied. Using the built-in strain in a bi-layer structure grown on lattice mismatched substrate, we are able to form micron sized rolled-up tubes by lifting off the strained layers using selective etching. We have developed techniques to precisely control the diameter, shape, size, and position of the microtubes. In this work, GaAs/InGaAs microtubes with embedded InAs quantum dots were fabricated. The light emission properties were studied using a specially designed optical pumping system, which was able to excite the tubes at desired locations. The rolled-up shape forms a natural ring cavity for the emitted light. Resonant modes of the ring cavity were clearly observed with the mode spacing agreeing with the theoretical predictions. Secondary longitudinal modes along the tube were also observed. Although no clear threshold was observed, the clear resonant modes without background emission, indicated very likely that the light emission was actually due to lasing action. The reason that the threshold is low can be attributed to the small cavity volume. We have also fabricated microtubes with a lateral P-N junction using Zn diffusion in an attempt to achieve electrically pumped microtube laser. Electrical measurement indicated the existence of the P-N junction. However, the high series resistance, probably due to poor ohmic contact, prevented us to see any lasing action. Further refinement of the processing techniques should allow us to achieve the electrically driven microtube laser in the near future.
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Chiu, Yen-Chieh, and 邱彥傑. "Response speed and optoelectronic characteristics of GaN based heterojunction phototransistors." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/89r2zj.
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碩士國立臺灣科技大學
電子工程系
105
In this paper, we characterized the GaN based phototransistors which made by seniors, including the dark current, external quantum efficiency (EQE), response speed, response time, noise of the phototransistor and the photocurrent versus incident light intensity. Instead of using a wafer with a bipolar junction transistor n–p–n epitaxial structure, we successfully fabricated AlGaInN-based near-ultraviolet (UV) heterojunction phototransistors (HPTs) on a commercial wafer with a light-emitting-diode (LED) epitaxial structure by employing silicon diffusion to convert a part of the p-AlGaN layer into an n-AlGaN layer. The device was emitter-side illuminated using an incident light intensity of 15.6 μW/cm2 at the fixed wavelength of 382 nm at which the responsivity was the highest. The EQE and responsivity were approximately 16600% and 51.4 A/W when VCE was 1V at 382 nm, respectively. It then increased the V¬CE of up to approximately 3 V, the peak EQE value of 38000% at 382 nm, corresponding to a responsivity 117.7 A/W. The cutoff wavelength was approximately 415 nm which was determined by the minimum bandgap energy of the MQWs. The response speed of our HPT was illuminated with the same condition like EQE, and the VCE¬ was set at 3 V. The dominating factor affecting the response speed was the fall time, which was measured to be approximately 85 ms and the rise time was approximately 15.8 ms, which might be acceptable for most applications. The results implied the potential to integrate an LED with a phototransistor monolithically and cost effectively.
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Pan, Chang-Chi, and 潘昌吉. "Study the Optoelectronic Characteristics and Vapor Growth of Polycrystalline GaN Films." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/47025715692646631088.
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碩士大葉大學
電機工程研究所
89
The feasibility study of polycrystalline GaN films deposited on as-cut poly-Si substrates by metalorganic chemical vapor deposition (MOCVD) is the main work in this article. From the measured results in terms of surface morphology, crystallinity, photolumincesence (PL), and optoelectric properties, the optimum growth parameters and mechanisms of poly-GaN can be established in this study. Hereafter, the metal-semiconductor-metal (MSM) photodetectors can be fabricated based on the poly-GaN/poly-Si materials system tailoring their unique optoelectronic properties. Details of this will be focused on the low-cost and large-area device applications. Based on our preliminary studies, it is found that strong room-temperature PL emission (3.387 eV) with an FWHM of 120 meV can be obtained for the as-grown poly-GaN films (~ 4 mm in thickness). The grain size for poly-GaN was ranged from 3 to 4 µm as examined by SEM. From Van der Pauw-Hall measurements, the as-grown poly-GaN films show n-type conductivity with carrier concentration of 2 ~ 7 × 1019cm-3. The electron concentration are high from the natural N-type GaN films in the two step growth system ( GaN as buffer layer ), and such high electron concertration films cann’t to suit to the production of Schottky-contacted MSM UV detectors. So we change to select AlN as our buffer-layer growth at low temperature about 500~600oc, and to change the component of AlN in the AlGaN layer, then the main layer GaN was grown at 1000oc. From Van der Pauw-Hall measurements, the as-grown poly-GaN films also show n-type conductivity with carrier concentration of 2 ~ 7 × 1017cm-3. Due to the I-V measured results of MSM UV detector based on the poly-GaN/AlGaN/AlN/poly-Si films, (the size is about 1 mm × 1 mm , the length of finger = 200 mm, width = 30 mm, space = 30 mm) the dark current is about 10-10A at the reverse-bias 5 V. From the illumination of He-Cd laser ( 325 nm line of a 40 mW ), the photocurrent of the illuminated MSM UV devices have the change of three orders. The MSM UV detector based on poly-AlGaN/poly-Si materials has many advantages than the conventional devices (e.g. PMT、Si or GaP-based photo-sensors coupled with UV transmission filters, and diamond films). UV photo-detector which can selectively detects the flame luminescence within the range from 250 to 280 nm is capable of detecting flames against the strong background of sun-light or room-light. Besides that, it is also important for flame detector to achieve low-cost, large-scale and high sensitivity to ultraviolet light (1nW/cm2) performance. Therefore, we hope to develop the novel optoelectronic materials and applications for poly-GaN/poly-Si. It is expected to open a new research field from this article.
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Liu, Wen-Hsiung, and 劉文雄. "Optoelectronic Characteristics of SiO2-Isolated Amorphous TFLEDs on c-Si Wafer." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/19862025824059483002.
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碩士國立中央大學
電機工程研究所
90
In order to investigate the feasibility of fabricating Si-based visible light-emitting diodes (LEDs) with common well-developed silicon processing technology, the SiO2-isolated n [phosphorous-doped hydrogenated amorphous silicon (n-a-Si:H) ] - i [intrinsic hydrogenated amorphous silicon-carbon (i-a-SiC:H) or intrinsic hydrogenated amorphous silicon-nitride (i-a-SiN:H)] - p [boron-doped hydrogenated amorphous silicon (p-a-Si:H)] thin-film LEDs (TFLEDs) were fabricated on n-type c-Si wafers. These SiO2-isolated TFLEDs would emit red-orange, green-white light and even light with voltage-tunable color. The red-orange TFLED revealed a highest brightness of 8100 cd/m2 at an injection current density of 600 mA/cm2, an electroluminescence (EL) peak wavelength at 600 nm, and an EL threshold voltage = 19.1 V. The green-white TFLED had a brightness of 370 cd/m2 at an injection current density of 300 mA/cm2, an EL peak wavelength at 528 nm, and an EL threshold voltage = 15.4 V. The voltage-tunable TFLEDs had the EL peak wavelength ranged from 565 nm to 670 nm at different applied voltages. The experimental results demonstrated the feasibility of developing Si-based visible light-emitting devices on c-Si substrate.
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Yen-TingChen and 陳彥廷. "Microstructure, Interface Crystallized Mechanism and Optoelectronic Characteristics of InGaZnO Thin Films." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/01646011313589136395.
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碩士國立成功大學
奈米科技暨微系統工程研究所
98
InGaZnO amorphous oxide semiconductor (AOS) is one of the most attention-getting materials in last years. IGZO has a good carrier mobility more than 10 cm2V-1s-1, even was deposited at room temperature; therefore it can be apply in the high-efficiency electronic devices and manufacture by low-temperature processes. However, there are still some reliability problems in the IGZO systems. The material basic properties and the device interface-effect mechanism are the keys to solve the problems. This present research is based on the film properties, and then produces devices to discuss the relationship between the interface structures and its electric resistance. It not only analysis material organization and structural characteristics, but also reports optoelectronic characteristics and the main interface mechanism of film by choosing IGZO system with different compositions (atom ratio: 1114 and 2217). Parts of the experiment choose 1114 system as the channel material of TFT devices, and then measure its electrifying properties and the relationship of IGZO interface structure in the device, finally then discuss the interface phase transformation characteristics was induced by electrical current testing. Results of the experiments show the film resistance of IGZO increase with increasing the flow rate of depositing oxygen. There is a greater influence in annealing conditions than depositing oxygen flow rate. The higher annealing temperature has the lower film resistance. However the variation becomes smaller while the annealing temperature over 250 oC, and the film basic composition and the depth distribution become stable. Besides, the film resistance of IGZO2217 is lower than that of IGZO1114. It was found that the IGZO compositions influence the TFT device characteristics seriously after actually measuring. While lacks Zn element of IGZO, the ZnO volume ratio decreases. This affects the carrier mobility due to the decay of the device characteristics seriously. The annealing process can induce the Raman shift peak CH (466). A stronger In2O3-Ga2O3 bond of IGZO2217 for CH peak value is greater than IGZO1114. The interfaces and matrix of In/IGZO film possess a phase transformation after electrical current testing. The transformation improves the resistance of IGZO films.
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Syu, Yu-Cheng, and 許育誠. "Study on Characteristics of Photonic Crystal Structures Applied in Optoelectronic Devices." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/75411703498723430282.
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碩士國立交通大學
顯示科技研究所
100
In this thesis, we investigated some applications of photonic crystals in optoelectronic devices. The content is divided into two subjects. In the first part, the high reflectivity GaN-based sub-wavelength high-contrast grating (HCG) had been demonstrated. Based on the 2D rigorous coupled-wave analysis (2D-RCWA) and finite-difference time-domain method (2D-FDTD), we found and confirmed the optimal structure that exhibits high reflectance (R > 0.9) for TE-polarized light over a wide spectral range (ΔλR ≈ 105 nm) centered at λ = 460 nm. Moreover, we decided some critical designs via parameter mapping which could realize the intended results with high fabrication tolerance to reduce the difficulties in the process. Finally, we successfully fabricated the membrane HCG and exploring the associated characteristics. It has excellent polarization selectivity and the measurement results were in good agreement with the simulation data. In the second part, through the transfer matrix method and coupled-wave theory, we studied the influence of various thicknesses on different layers in our structure. We especially focus on the band edge at Γ1 point because of the characteristic of photonic crystal (PC) surface emitting. The relationship between the threshold gain and filling factor had also been considered. In our ultimate results, the best value of vertically optical confinement factor of PC in the optimized GaAs-based PCSELs is calculated to be 12.6% and the threshold gain is reduced to 50 cm-1. In addition, we made some extended investigation about mode spectra identification and electrical property discussion.
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Yu-HuiHsu and 徐鈺暉. "Improvement of Optoelectronic Characteristics of GaN-based LED by Nano Structure." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/88467991341399867626.
Full textAbstract:
碩士國立成功大學
光電科學與工程學系
100
In this study, we produced nano structure on GaN-based LEDs to improve its optoelectronic characteristics. Roughened surface of LED was expected to reduce the light confined inside the device due to total reflection, with a corresponding increase in light extraction efficiency (LEE). In this experiment, we discussed two different variables. One was the different scales of nano structure; comparing their optoelectronic characteristics with conventional LED. We used 500nm, 700nm, 750nm and 1000nms’ polystyrene (PS) sapphire to produce four different scales of nano structure on LED. Under 20-mA current injections the light output power of 500nm, 700nm, 750nm, and 1000nm enhanced about 34.39%, 31.62%, 41.62% and 88.92%. The distribution area of nano structure was changed for the other variable. Nano structures distributed on selective regions and full regions. These two types of LED were analyzed optoelectronic characteristics too, comparing with conventional LED. The 20-mA of light output power of conventional LED, selective regions LED, and full region LED were 3.34, 4.74, and 4.42 mW. Finally, the divergence of epitaxial conditions led to nano structures with different shapes. The effect of different shapes on light output power was analyzed by Trace Pro optical simulation software. In addition, we used simulation software to check our experiment, as a confirmation that nano structure can actually improve LEDs’ light output power.
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Sie, Jheng-Ping, and 謝政平. "A Study on Pozzolanic Characteristics of Waste Glass from Optoelectronic Industry." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/54538786526509277042.
Full textAbstract:
碩士國立宜蘭大學
環境工程學系碩士班
101
This study investigated the pozzolanic reactions and engineering properties of waste film transistor liquid crystal displays (TFT-LCD) and solar panel waste glass -blended cements in relation to various replacement ratios (0–40%) and water-to-binder ratio (0.29-0.55). The waste glass blended cement (WGBC) pastes were subjected to setting time, compressive strength, pore structure, gel/space ratio and non-evaporable water content tests were also conducted. The microstructure of all samples was determined using XRD、FTIR、MIP、SEM and NMR. The goal of this study is to elucidate the pozzolanic characteristics of WGBC pastes containing waste glass when it is alkaline-activated, and to investigate its hydration products. The results indicated the compressive strengths of the WGBC pastes with 10-20% waste glass were was similar to those of OPC when the w/b ratios were 0.29-0.38. When the w/b ratios were 0.29-0.38, the capillary pore volume (<0.01 μm) of WGBC pastes decreased as curing time increased. The equation models variability in compressive strength, indicating a relatively strong correlation between the total pore volume, capillary pore volume, gel/space ratio, non-evaporable water content and compressive strength. The correlation coefficient (R2) is greater than 0.8. The hydration products of WGBC pastes, perhaps because of the initial attack of waste glass, which were involved mainly in the formation of C-S-H, C-A-H, C-A-S-H. This resulted in a very densified and homogeneous system, and a considerable increase in long-term strength. 29Si NMR spectrum indicated as the curing time increased, the relative intensity of the Q0 peak decreased. The Q1 and Q2 peak also increased with curing time. This is linked to an acceleration of the hydration kinetics with curing time, so that the anhydrous species were transformed into calcium silicate hydrate (C-S-H). These experimental results indicate using waste glass from optoelectronic industry as supplementary cementitious materials are feasible.
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Laih, Li-Hong, and 賴利弘. "IMPROVING THE OPTOELECTRONIC CHARACTERISTICS OF AMORPHOUS METAL- SEMICONDUCTOR-METAL PHOTODETECTORS (MSM-PDs)." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/80008220095179159970.
Full textAbstract:
碩士國立中央大學
電機工程研究所
83
In this thesis, six types of planar metal-semiconductor- metal photodetectors (MSM-PDs) made of hydrogenated amorphous silicon (a-Si:H) and its alloys on silicon wafer and Corning 7059 glass substrate were studied. To improve the responsivity of device,the transparent ITO(Indium-Tin-Oxide) metal was sputtered onto the i-a-Si:H layer. Experimentally, an increase of 2~3 times of the device responsivity was observed. The top-electrode device fabricated on silicon wafer had the better DC I-V characteristics and its spectral response was within 500 ~ 950 nm, which was more broader than that of the one with bottom-electrodes , and covered the 830 nm wavelength used in the short-range fiber communication system . Since the a-Si:H has a lot of defects and its life- time is shorter, so the falling (turn-off) time of the device during switching was reduced, and a high response speed was expected. Experimentally, a bandwidth speed of 10 ~ 15 GHz was obtainable.
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Chiu, Yueh-Jye, and 屈岳杰. "The optoelectronic characteristics study of nitride based to ohmic contact and LEDs." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/14031470458384563111.
Full textAbstract:
碩士國立成功大學
微電子工程研究所碩博士班
93
In recent years,GaN material is applied to optoelectronic devices,such as photodetectors, light-emitting diodes and laser diodes. But the p-type GaN is more difficult to find out that the specific contact resistivity is below 10-5 Ω-cm2 than n-type. Good ohmic contact is important for devices performance. In addition, there are two key obstacles for ohmic contact to p-type GaN. (i) It is a difficulty in growing heavily doped p-type GaN(>1018cm-3) and (ii) it is the absence of appropriate metals which have a work function higher than that of p-type GaN(6.5eV). Based on above, many groups have attemped to achieve low-resistance ohmic contact on p-type GaN. Secondly, the metal layer(semi-transparent) of LEDs is a key point to affect the current spreading. Uniform current distribution is needed for better devices performance than none and enhanced light output intensity. In our experiments, we try to find out good ohmic contact by different metal combinations, such as Ir/Pr, Ir/Nb, Pt/Ir, Ni/Au Ni/Nb and Ir/Au. According to different surface treatment and annealing time, measuring I-V characteristic (including in varied temperature ambiance) to computer experimently specific contact resistivity(ρc) and the Richardson constant(A*). From theoretically I-V property, we calculate effective barrier height(φb) and ideality factor(n). We also have analyzed by SIMS. Finally, we attempt to deposit different metal contact layer e.g. Ir/Au, Ir/Nb, Ir/Ni, Ir/Ru, Ni/Au, and Ni/Nb, on the top of SPS LEDs and compare with optical and electrical properties, respectively.
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Tasi, Chorng pyng, and 蔡崇平. "Synthesis And Optoelectronic Characteristics Of Transparent Conductive P-type CuCrO2 Thin Films." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/70957319563588363317.
Full textAbstract:
碩士亞洲大學
光電與通訊學系碩士班
100
This study was conducted in two stages. In the first stage, Cu-Cr-O films were prepared using magnetron sputtering deposition and then annealed for one hour under controlled argon atmosphere at the temperature of 500, 600, and 700℃. The as-deposited film was amorphous. Through annealing at 500℃, the film formed a structure as a combination of CuO and CuCr2O4; through annealing at 600°C or higher, the film turned to a delafossite-CuCrO2 structure. As the annealing temperature rose to 700℃, the average grain size in CuCrO2 film increased which leads to the reduction of grain boundary areas and the number of point defects. This reduction increased the carrier mobility from 0.487 to 0.648 cm2/Vs. Also, the reduction of point defects, the origin of hole carriers, caused the carrier concentration to decrease from 3.16×1017 to 2.05×1017 cm-3. The 600℃-annealed film had the lower resistivity of 35.46 Ωcm, with a direct energy band gap value of 3.08 eV and a light transmittance rate of 72% at 800 nm visible light. In the second stage, different deposition parameters of the O2/(O2+Ar) ratio were employed to deposit the Cu-Cr-O films, including 40, 50, 60, and 70 %. After sputtering deposition, the film was annealed under argon atmosphere at 600℃ for 4 hours. The films were a composite-phase structure of CuO and CuCrO2 that deposited at the O2/(O2+Ar) ratio of 40 and 50 %. The film was a single-phase CuCrO2 which deposition parameters corresponding to the O2/(O2+Ar) ratio equal to and higher than 60 %. FESEM demonstrated that the O2/(O2+Ar) ratio higher than 60 % significantly decreased the thickness of the film to 106 nm. This could be explained by that the relatively high concentration of oxygen led to formation of oxide on the CuCr target surface, and in turn decreased the sputtering yield of the target. By adjusting the composition of the sputtered atoms, the film was formed as a single-phase CuCrO2 structure. The single-phase CuCrO2 film had the transmission of 68 % at 550 nm. The single-phase CuCrO2 films had direct energy gap values of 3.15 and 3.16 eV, respectively. Hall-effect measurement revealed the increased carrier concentration in the single-phase structure that lowered the resistivity values of 2.35 and 2.61 Ωcm, respectively. The carrier mobilities were was 0.19 and 0.18 cm2/Vs, respectively. The carrier concentrations were 1.2×1019 and 1.4×1019 cm-3, respectively. The positive Hall coefficients indicated that the main electricity carriers in CuCrO2 films were holes (h+).
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Chuang, Fu-Tsun, and 莊富存. "Study the Optoelectronic Characteristics of InGaN/GaN Multi-Quantum Well Light Emitting Diode." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/68577322707882964162.
Full textAbstract:
碩士長庚大學
電子工程研究所
94
To investigate the so-called exciton localization effect, electro- and photoluminescence spectra of light-emitting InGaN/GaN multi-quantum wells structures with different well thickness are studied over a broad range of temperatures and pumping levels. In principle, the exciton localization effect is the consequence of indium spatial fluctuations in the energy gap. Based on a band-tail model, assuming a Gaussian shape of the band tail, the exciton localization effect is studied in this work. The excitation-power dependent PL measurement shows exciton localization effect dominates rather than QCSE in our system. We find the fitting parameter “σ”, the degree of localization effect, is conform to LOP which is measured by electroluminescence. Details are discussed in this thesis.
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Fu, Yi-Keng, and 傅毅耕. "Optoelectronic Characteristics Study of Nitride-based ight-Emitting Diodes and Solar Cell Devices." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/29493302859880830796.
Full textAbstract:
博士國立中央大學
光電科學研究所
98
In this dissertation, the growth and characterization of multiple MgxNy/GaN buffer layers and InGaN/GaN blue light-emitting diodes have been studied. The improvement of both LED light output power and efficiency droop are investigated. In addition, we also discuss the optoelectronic characteristics of nitride-based solar cells with MQW absorption layer. The primary results obtained in this dissertation are summarized as follow: (a) It was found that the GaN grown on MgxNy buffer layer showed lower dislocation density (~2.2 × 108 cm-2), higher carrier mobility (~630 cm2/Vs), lower background carrier concentration (~5.1× 1016 cm-3) and narrower FWHM of (002) (~228 arcsec) and (102) (~248 arcsec) in DCXRD, as compared with conventional GaN grown on low-temperature (LT) GaN buffer layer. The blue LEDs grown on 12-pairs MgxNy (120 sec)/GaN buffer layers could also reduce the reverse leakage current and enhance the LED output power from 5.36 mW to 5.97 mW at a 20 mA current injection, as compared with conventional LEDs. (b) For GaN-based LEDs, nitride-based asymmetric two-step LEDs with a In0.08Ga0.92N shallow step was proposed and fabricated. By inserting an In0.08Ga0.92N shallow step, it was found that LED output powers can be improved from 2.9 mW to 6.6 mW under a 20 mA current injection. The improvement of output power could be attributed the fact that the significant carrier localization effect in the asymmetric two-step LEDs can lead to higher IQE. Under high injection current density, LEDs with InN/GaN multilayer wells (MLWs) structure can improve both the light output power and efficiency droop, compared to the conventional InGaN MQW LED. Under an injection current density of 500 A/cm2, we can enhance LED output power from 71.0 mW to 89.4 mW, compared to conventional LED. As compared to the EQE at an injection current density of peak value, the EQE values at an injection current of 500 A/cm2 are approximately reduced by 47 % and 21 % for the conventional LED and InN/GaN MLWs LED, respectively. These improvements could be attributed to the InN/GaN MLWs can significantly reduce the threading dislocations generated from active region, improve the interfacial quality between QW and QB, enhance the localized state and release strain in InGaN layer grown on GaN. (c) For GaN-based solar cells, The MQW structure should be able to maintain the material quality of high-indium-content InGaN alloys, leading to better device performance than devices with a single InGaN layer as the active layer. The short-circuit current density (JSC) and open-circuit voltage (VOC) can be modulated by different arrangement of blue and green QW in MQW absorption layer. The optimal electrical characteristics of solar cell with JSC = 0.473 mA/cm2, VOC = 1.30 V, fill factor (FF) = 0.630 and conversion efficiency = 0.39 % with AZO transparent contact layer (TCL) can be obtained.
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Lin, Shihchin, and 林士欽. "Structure Development, Optoelectronic and Magnetic Characteristics of Zero- and One-Dimensional Nanoscaled Materials." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/24639510029390880376.
Full textAbstract:
博士國立交通大學
材料科學與工程系所
96
Material with nanometer-scale size have large ratio of surface to bulk atoms. Large surface always gives high active behavior and changes in both physical and chemical properties. Nanomaterials such as nanoparticles, nanotubes, nanorods and nanowires having size generally smaller than 100nm exhibit superior photoelectronic and magnetic properties in various applications. Therefore, in this thesis, the studies will be focused on the synthesis, structure analysis and property characterization of zero-/one dimensional nanoscaled materials. In chapter 2, ZrO2, TiO2, ZnO and Al2O3, were chosen as raw materials to synthesize a target for laser ablation. The formed nanoparticles exhibit two kinds of particle size distribution with 7~15 nm (70~90%) and 40~100 nm (10~30%). Nanoparticles synthesized at lower fluence laser ablation are rich in Zn composition and show more narrow distribution. While increasing laser fluence, the composition of the collected nanoparticles is primarily composed of Zr. A model based on composition and morphology of both nanoparticles and target with changing laser fluence was proposed to explain the phase evolution of nanoparticles. The average far-infrared emissivity of the nanoparticles based on ZrTiO4--ZnAl2O4 system is measured to be more than 80﹪(wavelength range from 4 to 12 μm) and varies with crystal phase ratio. In chapter 3, a highly dispersed nano-TiO2/Ag catalyst is synthesized in an alkaline solution. Nearly all of the dimethy-blue target pollutant at high concentration was removed when the photoreaction was performed in a short period. This novel nano TiO2 photocatalyst exhibits excellent photocatalytic activity because it is well dispersed. Since no dispersant or organic binder was used, this synthetic process has the advantages of low cost and convenience. In chapter 4, One-dimensional nanotube arrays of nickel-phosphate have been developed by electroless deposition into sub-micro to nanometer sized pores of the porous alumina templates. The dimension of the formed nanotubes has 1μm in length, 200~300nm in diameter and 80~150nm in thickness of tube walls. Transmission electron microscopy examination of the nanotubes clearly show amorphous hallow structure with a average grain size of ~5 nm. The hysteresis loops of the nanotube arrays show a coercive field of about 200Oe under treatment in 95%N2/5%H2 atmosphere at 500 oC as the magnetic field was applied along parallel and perpendicular to tube axis. The nanotube arrays also exhibit an anisotropic magnetic property with easier saturation along the perpendicular direction. However, both coercive field and saturation of remanent magnetization of the nanotube arrays become lower while continually increasing heat treatment temperature up to 900oC. In chapter 5, ordered silver- nickel core-shell nanowire arrays were successfully fabricated by electrodeposition. The ordered silver nanowire arrays embedded in a porous alumina template were first fabricated from an aqueous solution of Ag(NO3)2 and Ac(NH3). After removing out the template, the obtained silver nanowire arrays were subsequently electrodeposited with nickel at 1.6~2.6V and 60oC using the electrolyte composed of NiSO4, NiCl2 and H3BO3. Transmission electron microscopy (TEM) observation reveals that a 15 nm thick nickel film was coated on the surface of the silver nanowires with about 200 nm in diameter. It was found that the silver nanowires with nickel coating showed enhanced magnetic properties in comparison to that of pure silver nanowires. The Magnetic Force Microscope (MFM) image of silver- nickel core-shell nanowires exhibits magnetic domain state. In addition, the hysteresis loops of the silver-nickel nanowire arrays show a coercive field of 180Oe, almost independent of the applied magnetic field parallel and perpendicular to nanowires. However, it was observed that a larger magnetic domain was found in parallel direction than that in perpendicular direction. In chapter 6, a single bath electrodeposition method was developed to integrate nanowires of Ag/Co with multi-layer structures within a commercial AAO (anodic alumina oxide) template, with a pore diameter 100~200 nm. An electrolyte system containing silver nitride and cobalt sulfide was explored by using cyclic-voltammetry and electrodeposition rate to optimize electrodeposition conditions. A designed step-wise potential and different cations ratio [Co2+] / [Ag+] were adopted for the electrodeposition. After dissolution by NaOH, Ag/Co multilayered nanowires were obtained with a composition {[Co]/[Ag80Co20]}30 identified by XRD and TEM when [Co2+] / [Ag+] = 150. By annealing at 200oC for 1hr, the uniformly structured {Co99.57/Ag100}30 nanowires were obtained. Compared with pure Co nanowire, the magnetic hysteresis loops showed manifest magnetic anisotropy for {Co99.57/Ag100}30 nanowires than that of pure Co nanowires corresponding to a change of easy axis upon magnetization. In chapter 7, The heterojunction photovoltaic devices consist of hybrid p-type organic Cu-phthalocyanine and inorganic n-type semiconductor ZnO nanostructures which include vertically aligned nanorods, randomly oriented nanorods and nanoparticles. The strong absorption of ZnO appears in 250~460nm wavelength and Cu-phthalocyanine exhibits broad absorption in 440-700nm with an absorption maximum at 630nm. The incorporation of partial Al into ZnO leads to the shift of absorb light from UV region to visible light and subsequently causes more charge generation. Charge recombination from hybrid devices of vertically aligned ZnO nanorods was more efficient than that fabricated from the other types. The maximum incident photon to electron conversion and energy conversion efficiencies under simulated sunlight AM1.5 (10mW/cm2) in aligned ZnO are 0.036mA and 1.32%, respectively. In chapter 8, a new 1 and 2 dimension nano structure for making solar cell or TFT module have been researched by adopting low cost coated glass substrate with polysilicon instead of silicon wafer. Meanwhile, laser annealing is used as the unique method to melt primal amorphous silicon thin film and promote it recrystalize under low temperature. Particularly, the new thermal conducting layers are patterned under the silicon layer to enhance the lateral giant grain growth. The important processes are represented as follows: 1. A electrical conducting layer are formed on the glass substrate. 2. Photolithographic process is executed to pattern the thermal conducting layer and form many variable thermal conducting zone. 3. An about 200nm amorphous silicon film is formed on the patterned thermal conductive layer. 4. A thermal isolation layer such as SiO2 is deposited for keeping laser annealing temperature. 5. While the pulse excimer laser is injected the structure, the amorphous silicon film can absorb laser energy instantaneously and transform it to crystalline type. Moreover, the temperature gradient could be generated on the silicon layer and cause the uniform polysilicon growth of 1~2μm giant grains under about 450-475mJ/cm2 laser fluence. A unique method of multiple laser fluence have been executed to increase the crystalline orientation of Si(111).
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Lin, Chin-Ching, and 林晉慶. "Optoelectronic Characteristics and Structure Development of One- and Two-Dimensional Zinc Oxide Materials." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/57464825229943960629.
Full textAbstract:
博士國立交通大學
材料科學與工程系所
94
Zinc oxide (ZnO) has unique physical properties that make it a most promising material for optoelectronic device. The main reasons are a direct band gap of 3.3 eV and a large exciton binding energy (60 meV), which permits exciton recombination even above room temperature. Owing to its distinctive characteristics the research trend on ZnO has continued for many decades. The former studies are focused on the basic physical properties of three- and two-dimensional ZnO materials, such as lattice parameter, vibrational properties, and optical studies. As improving the technology of materials growth, scientists have more opportunities to produce high-quality ZnO materials and then can do deeply research in it. In this nearly decade, the main obstacle to the development of ZnO has been the lack of reproducible and low-resistivity p-type ZnO. For the moment, many groups have attacked this problem and several have been successful to solve some problems of them [64-67]. Moreover, theoreticians have also been active in this area, and have predicted the electrical activities of various dopants and native defects [68-70]. In addition to ZnO thin films, significant interest has emerged in the synthesis of nanoscale ZnO materials, in recent years. It is due to the one-dimensional ZnO nanostructures provide an attractive candidate system for fundamental quantization and low-dimensional transport studies for chemical sensing and biomedical applications. This thesis outlines the process of fabricating p-type ZnO thin films and one-dimensional ZnO nanostructures, as well as the study of their physical properties. In chapter 1 we will present an introductory overview to ZnO materials. It is devoted, respectively, fundamental, doping, and defects properties in ZnO. Chapter 2 will discuss the fabrication of one- and two-dimensional ZnO materials and basic theoretical concepts of nanoscience. This chapter also includes how we developed high-quality ZnO films and nanorods and measured their excellent physical properties. The individual nanorod measurement setup for electrical transport is also shown in this chapter. Chapter 3 discusses the defects engineering on ZnO thin films. The transitions of native defects in ZnO are inspected by photoluminescence (PL) spectroscopy, in this study. Different buffer-layers could change the concentration of native defects and improve the physical properties of ZnO. We will, therefore, discuss the relationship between the predominant defects and PL emissions in the ZnO films. In chapter 4, we will present the results for the electrical and optical properties of group-V elements doping in ZnO films. Reproducible p-type ZnO films with high carrier concentration (7.3 1017 cm-3) are fabricated by nitrogen-implanted on nitride layer and then annealed at 850 oC in N2 ambient. To date, the most popular method to grow ZnO nanorods is vapor-solid process. However, this method is usually operated under high temperature and it has also locked the size of the sample due to the size of the furnace. In chapter 5, we will show a convenient method to produce large scale ZnO nanorods on organic and inorganic substrates. The growth mechanism and thermal annealed effect of ZnO nanorods will be investigated by high-resolution transmission electron microscopy. The plasma treatments are used to improve the luminescent and electrical properties in ZnO nanorods. The high conductivity n-type and rectifying behavior p-type ZnO nanorods are revealed in chapter 6. The electrical transport of individual ZnO nanorods and single-walled carbon nanotubes composite will be discussed in chapter 7.
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Hung, Hung, and 洪洪. "The optoelectronic characteristics study of nitride based MQW LEDs grown using MOCVD techniques." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/31896002808006693928.
Full textAbstract:
碩士國立成功大學
微電子工程研究所碩博士班
92
In this thesis, the properties and characteristics investigation of nitride based multiple quantum wells light emitting diodes which had been fabricated by metal organic chemical vapor deposition were demonstrated. The simulation results using “MEDICI” of different barrier doping location and concentration were compared with experimental results. Furthermore, the parameters of quantum well such as barrier and well thickness and barrier doping condition were confirmed using x-ray diffraction, photoluminescence and electroluminescence. From the experiments, different doping location changes the forward voltage at 20mA (i.e. VF2) of LEDs. Then, barrier thickness of 215Å is determined with the best quantity in this structure due to better electron-hole recombination mechanism. Besides, the narrower well thickness shows better quantum confinement then contributes to LED luminescence. The well thickness is dominant in energy transition; hence different well thickness changes emitted light of LED. In addition, higher barrier doping concentration can lead to better crystal quality owing to the doped silicon make up for the defects. Further, the highest transparency of ITO film was obtained with 450°C annealing temperature and 1800 Å thickness separately. In summary, the studies of quantum well doping, thickness and pair were demonstrated to verify their characteristics, and simulations also show a considerable tool to design and determine to characteristic of optical devices.
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Jen, Chau-Yun, and 鄭朝雲. "Study on the Fabrication and Optoelectronic Characteristics of the Hydrogenated Amorphous Silicon Photoreceptors." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/23878992164931931188.
Full textAbstract:
碩士國立雲林科技大學
電子與資訊工程技術研究所
85
Multilayered hydrogenated amorphous silicon (a-Si:H) thin films prepared by plasma enhanced CVD have been actively studed for application to electrophotographic photoreceptors. It contains not only the properties of high hardness, stability, and transparency in the hydrogenated amorphous carbon(a-C:H) but also the excellent photosensitivity, good thermal stability, excellent mechanical strength and nontoxicity of the hydrogenated amorphous silicon. We find the optimization of the growth rate for hydrogenated amorphous silicon deposition using orthogonal design method. The transport of excess carriers in photoreceptors, mobility-lifetime product (μτ) and energy barrier were studies by electrophotography and current-voltage curves have been used to explain the optoelectronic characteristics of photoreceptor. In this study, we designed and prepared these structures of the electrophotographic photoreceptor to by the concept of separate function, these structures are a-C:H/a-Si:H(i)/a-Si:H(n-)/Al2O3/Al, a-C:H/a-Si:H(i)/a-Si:H(p-)/Al2O3/Al and a-C:H/a-Si:H(n-)/a-Si:H(i)/a-Si:H(p-)/Al2O3/Al. The a-C:H layer is also proved to be an excellent surface passivation layer. These structures measured with the electrostatic paper analyzer for the photoinduced discharge curve (PIDC). From our ecperimental results, the a-C:H/a-Si:H(i)/a-Si:H(n-)/Al2O3/Al structure shows the higher surface potential (540V, 36V/μm), long decay time 6 sec, good photosensitivity 8Lux.sec and residual potential 22V. However, In this study a-C:H/a-Si:H(i)/a-Si:H(n-)/al2O3/Al structure has the good optoelectronic properties. It can be widely used for the xerographic machine.
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Chuang, Chi-Yang, and 莊基陽. "Study of Optoelectronic Characteristics of GaN-based LEDs Using Various Current Blocking Layer." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/58674749158326620331.
Full textAbstract:
碩士國立中央大學
光電科學研究所碩士在職專班
95
Improving non-uniform current spreading to obtain high light-output efficiency is one of most important topics of GaN-based light emitting diodes (LEDs). Moreover, in conventional design of LEDs, light generated under the opaque p-pad metal contact is absorbed or reflected back by the contact and re-absorbed by material. It will reduce the efficiency of light-output. The main purpose of this thesis is to investigate three different current blocking layer (CBL) fabrication processes, including deposition of SiO2, Inductively Coupled Plasma (ICP) etching and ion implant to increase the brightness of LEDs. For qualification the change of these three surface treatments, tested samples with transmission-line model pattern have been applied to acquire the readings of series resistance. The highest resistance readings are 3.83×106Ω, 6.62×105Ω and 8.36×107Ω for SiO2, ICP and ion implant, respectively. Achievements of LED component using CBL structure, we observe the light output power of three kinds of methods are enhanced by 3.7~9.1%, 3.2~7.1% and 5.9~7.2%, respectively. But in electricity property, each process will make forward voltage a slightly higher 0.03~0.09V, 0.03~0.07V and 0.03~0.09V due to decrease of contact surface of p-GaN. Finally, relation between readings of series resistance and improved light output LEDs with CBL structure has been discussed by these evidences and possible mechanism has been induced in the thesis.
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Lin, Shao-Yang, and 林少洋. "Optoelectronic characteristics study of InGaAs quantum dot solar cell with AlGaAsSb capping layer." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/2x2mz4.
Full textAbstract:
碩士元智大學
電機工程學系丙組
107
This study investigated the effects of indium gallium arsenide (InGaAs) quantum dots (QDs) covering aluminum gallium arsenide antimony (AlGaAsSb) on the optoelectronic properties of the future solar cells. Since the QD emission wavelength is positively correlated with the indium-containing composition of the quantum dot structure, the carrier limitation, and the internal compressive stress, the shorter emission wavelength indicates the lower material structural stress and the epitaxial defects that may occur, and the preferred material. quality. In order to avoid quantum dot defects caused by excessive stress, the preparation of optimal luminescent wavelength quantum dots has a considerable influence on the efficiency of future quantum dot solar cell devices. This research direction is based on the study of 6.6ML InGaAs quantum dots. For the further structural design of the capping layer, the difference of the presence or absence of aluminum between the antimony-containing aluminum capping layer and the antimony-containing capping layer is compared.The quantum dots with the AlGaAsSb capping layer have a distinct first excited state, and the quantum dot photoluminescence intensity is significantly better than that of the antimony-containing cladding layer (2 nm GaAsSb). The possible reason is that the aluminum-containing cladding layer can improve the carrier confinement of the QD structure, so the PL luminous intensity of QD can be increased. In addition, the aluminum-containing structure can reduce the In-Ga intermixing phenomenon between the quantum dots and the capping layer, so that the longer wavelength of the emission is extended to 1210 nm, and the quantum carrier has a special carrier limitation, and the first excitation can be exhibited by the spectrum. This quantum dot structure of good optical properties is expected to increase the open circuit voltage of aluminum-containing quantum dot solar cell devices and their overall device conversion efficiency.
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Huang, JAU-Fong, and 黃昭峯. "The Optoelectronic Characteristics of Dye-Sensitized Solar Cells with B2O3-Doped ZnO Film Electrodes." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/57428784785903125183.
Full textAbstract:
碩士明新科技大學
電子工程研究所
102
Abstract The doping of B2O3 with various weight percentage in ZnO thin films have been prepared by doctor blade technique and the thin-film physical characterization is also measured and analysed. Simulatneously, the dye-sensitized solar cells with various doping amount of B2O3 in ZnO-based photo-anode electrode have also been prepared via standard procedure and their device characterization are also measured and analysed. The main purpose for this research focuses on studying the effect of B2O3 with various doping amount in ZnO thin film on optoelectronic charctaeristics, VOC, JSC, FF and , of the dye-sensitized solar cells with ZnO-based photo-anode electrode. Experimental results show that the dye-sensitized solar cell with undoped ZnO-based photo-anode electrode exhibits efficiency of 1.38%, but the dye-sensitized solar cell with 1.0 wt% doping amount of B2O3 in ZnO-based photo-anode electrode exhibits the short-circuit current of 3.84 mA/cm2, open-circuit votage of 620mV, fiill factor of 42% and energy efficiency of 1.02.%. The doping of B2O3 with various weight amount in ZnO thin film results in the negative effect on optoelectronic charctaeristics of the ZnO-based dye-sensitized solar cells. The degradation mechanism of the ZnO-based dye-sensitized solar cells with doping B2O3 maybe due to the interaction between boron ions and electrolyte and the formation of excess defects to faciliate the recombination of photoexcited carries, and furthermore result in the decreasing of energy conversion efficiency. Besides, boron oxide with hygroscopic property leads to the formation of incomplete and low-dense film and higher resistivity for the resultant films. Keywords: boron oxide, zinc oxide, dye-sensitized solar cells, photo-anode electrode.
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許立民. "Optoelectronic Characteristics of Oxidized Porous Silicon-LEDs with Amorphous n-i-p-n Layers." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/46526658385698780943.
Full textAbstract:
碩士國立中央大學
電機工程研究所
88
In this study, the conventional plasma-enhanced chemical vapor deposition (PECVD) system with an additional stainless steel (s.s.) mesh attached to cathode was used to deposit n-i-p-n a-Si:H layers onto oxidized porous silicon to form oxidized porous silicon light-emitting diode (PS-LED). The obtained PS-LED had a higher brightness (B) and a lower threshold voltage (Vth), as compared with the PS-LED fabricated with the same PECVD system without a s.s. mesh. The improvements of opto-electronic characteristics for the PS-LEDs would be mainly due to the used s.s. mesh, which would result in a deposited film with less plasma damages. Also, n-i-p-n a-SiC:H layers were used to fabricate the PS-LED, to further improve device performances. The obtained PS-LED had the better optoelectronic characteristics, but its electroluminescence (EL) peak wavelength was red-shifted, probably due to, although the a-SiC:H layer had a higher optical band-gap but it also had a more random and hence more tail states, so the electron-hole pairs had more chance to be recombined through tail states.
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Hong, Yu-Han, and 洪鈺涵. "VOCs Emission Characteristics and Management─A Case Study on Integrated Circuits and Optoelectronic Industries." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/9prtaw.
Full textAbstract:
碩士國立臺北科技大學
環境工程與管理研究所
101
This study use material flow analysis method to know the environment distribution of main representative VOCs in the inside and outside plant and the actual output of waste to analyze environmental risk, and provide a stationary source control. It is expected to conform economic efficiency and pollution reduction to improve the quality of the urban environment. The two representative plants we selected are from integrated circuit industry and optoelectronic industry, the developing technology industries in Taiwan. The company A of integrated circuit industry and company B of the optoelectronics industry are under survey to explore the environmental distribution of fixed pollution source of VOCs, estimation of factors of waste output and its management measures. The result shows, during the manufacturing process of company A of integrated circuits, two main species of fugitive VOCs emissions were isopropanol 0.03 (kg/hr) and acetone 5 × 10-5 (kg/hr ). Calculated the potential value of isopropanol largest fugitive emissions of ozone formation potential was about 140 ton/year (47%). While in LED manufacturing process of photoelectric company B, two main species of fugitive VOCs emissions were isopropanol 0.017 (kg/hr) and acetone 0.018 (kg/hr), the fugitive emission with acetone to maximum values of the ozone formation potential of approximately acetone 1.6 ton/year (41%) of the maximum value. By use of material flow analysis method for two processes of DF estimated by the findings that amount of waste production and raw materials, product yield and so have a linear relationship, and this can be applied to environmental management. Using an economic incentive that caused by the air pollution fee system, which price controls air pollution amount, and standard regulation, we can achieve effective air pollution reductions and economic benefit and establish waste generation factor estimation formula. This formula can estimate volume of waste output in actual site and practice to audit management as a comparison tool to inspect claim data of industry contaminant and on-site verification in advance, and effectively achieve objective of waste management.
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Fang, Ching-Chih, and 方勁智. "Investigation on optoelectronic characteristics of GaAs/SiO2/Ge heterostructure prepared by RF magnetron sputtering." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/m427f6.
Full textAbstract:
碩士國立臺北科技大學
光電工程系研究所
102
In this work, a SiO2 buffer layer was first grown on Ge substrate, and then GaAs thin films were deposited on SiO2 buffer layer and Ge substrate by RF magnetron Sputter. Next, the sample is examined by Transsmittance Spectrum、Scanning Electron Microscope（SEM）、X-ray Diffractometer（XRD）、Raman Spectrum. The analysis of X-ray diffraction showed that all the GaAs thin films with and without SiO2 had a zinc blende structure. The optoelectronic characteristics of GaAs/SiO2/Ge heterostructure were investigated. The experiment focuses on three parts, one through the thin film analysis to discuss GaAs / Ge and GaAs/SiO2/Ge two structures, and discuss the impact of changes in the SiO2 thickness; second is to investigate the GaAs / Ge and GaAs/SiO2/Ge voltage and current changes under light illumination; Third, analyze RF magnetron sputtering of GaAs crystal growth technology quality.
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Yang, Cheng-Jung, and 楊承融. "Optoelectronic Characteristics and Equivalent Circuit Analysis of Arrayed Electrochromic Display Based on Tertiary Colors." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/31546042838835453653.
Full textAbstract:
碩士國立雲林科技大學
電子工程系
102
In this thesis, the poly(3-methylthiophene) (PMeT) and the polyaniline (PANI) of the electrochromic thin films had been deposited on the zinc oxide nanowires/indium tin oxide/glass (ZnO nanowires/ITO/Glass) substrate by cyclic vltammetry (CV). First, the ZnO seed-layer was deposited on ITO/Glass by RF sputtering to investigate uniformity with different deposition mothods. Second, the ZnO nanowires were grown on the ZnO seed-layer by chemical bath deposition (CBD), which were investigated aspect ratio for different growth time. The PANI and PMeT thin films were deposited on ITO/Glass and ZnO nanowires/ITO/Glass by cyclic vltammetry. The electrochromic thin films ZnO nanowires/ITO/Glass was analyzed optical and electrochemical properties by photonic spectrometer, electrochemical impedance spectroscopy (EIS) and cyclic vltammetry, we found that the PANI and PMeT thin films was deposited for 9 hours on ZnO nanowires/ITO/Glass, which have the best transmittance variation (∆T550 nm=38 %) and optical density change (∆OD550 nm = 0.462), and the response time are 10 sec (T550 nm), 24 sec (T450 nm) and 28 sec (T650 nm). The chromaticity coordinates of PANI and PMeT thin films which deposited on ITO/Glass has the best shape of tracks.
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Wu, Chung-Hsun, and 吳忠訓. "Optoelectronic Characteristics Of ZnO/TiO2 thin films on ITO Substrate by RF Magnetron Sputtering." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/43990511007136440772.
Full textAbstract:
碩士國立中興大學
物理學系所
102
This work studies the optoelectronic properties of zinc oxide (ZnO) and titanium oxide (TiO2) thin films on ITO and Nb/ITO glass substrates respectively. ZnO and TiO2 thin films are fabricated on substrates using RF Magnetron Sputtering System. The topography characteristics and structures of thin films on ITO and Nb/ITO glass substrates are investigated using field emission scanning electron microscope (FE-SEM), energy scattering spectrometer (EDS), atomic force microscope (AFM),transmission electron microscope (TEM), optical microscope (OM), and X-ray diffraction analysis (XRD). The optical properties of thin films on substrates are measured using photoluminescence spectroscopy (PL), UV / Vis spectrometer (UV / Vis) for transmission, reflection and absorbance measurement, respectively. Our results demonstrate that characteristics of ZnO and TiO2 thin films on ITO and Nb/ITO substrates are dominated by the coating thickness of thin films. Finally our fabricated substrates have affective impacts in optoelectronic industry applications.
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Yeh, Der-Hwa, and 葉德華. "The investigation on characteristics of optoelectronic semiconductors doped with noble metals-palladium and platinum." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/84926791690591628889.
Full textAbstract:
博士國防大學中正理工學院
國防科學研究所
95
The GaAs and GaN semiconductor are III-V materials that are extensively used in the optoelectronic field. In this dissertation, we adopted the noble metal (platinum and palladium) and doped them into compound semiconductor materials (GaAs and GaN) and relative devices. We discuss the correspondent diffusion mechanism and the optical as well as the electrical characteristics of Pd and Pt doped III-V materials. From the experimental results, we observed that the palladium and platinum are both fast-diffuser and the interstitial-diffusion is a dominant mechanism for them on both GaAs and GaN semiconductor materials. For GaAs material, the platinum and the palladium own the activation energy of 0.95eV and 0.35eV, respectively. As to the GaN material, the platinum has an activation energy of 0.914eV and the palladium has an activation energy of 1.252eV. The resonant-cavity light-emitting diodes (RCLEDs) have narrow spectral line-width, better emission directionality, better couple efficiency, high brightness, easy fabrication, and the lowest fabrication cost. Therefore, the RCLED is the optimum selection for short-haul plastic fiber communications. In this dissertation, we also have completed the noble metal platinum doped RCLEDs fabrication. These platinum-doped RCLEDs exhibit the benefits of short rise time for switch operation and can be modulated at a higher modulation speed. The proposed noble metal doped technique can greatly increase the efficiency of fabricated RCLEDs with a modulation speed of up to 55%. Furthermore, these platinum-doped RCLEDs also have a high characteristic temperature (T1) of 320K.
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Yeh, Chihwei, and 葉志偉. "The Effect of Physical Feature of Phosphor to the White Light LED Optoelectronic Characteristics." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/63091534035367090930.
Full textAbstract:
碩士國立聯合大學
LED光電製程產業專班
100
In this study, we demonstrated the white light LED by introducing the yellow phosphor on the blue light LED chip. The yellow phosphor was excited by the blue light of LED chip and the white light was generated with the mixture of blue and yellow light. Two methods, grind and ultra-sonic sieving, were used to process the phosphor and the optical characteristics of the phosphor after processing were compared and discussed. We found that the nanoclusters of the phosphor were smaller and more uniform after the grinding process. However, the damage of the phosphor with grinding process caused the surface defects and resulted in lower illumination efficiency and color rendering index (CRI). Contrary, with the ultrasonic sieving method, the particle size of the phosphor with the diameter of 7 m could become more uniform and the optical properties were almost the same as the phosphor without any treatment. Moreover, particle size of the phosphor after various processes was confirmed by scanning electron microscope (SEM). We found that the nanoclusters were greatly reduced and the particle size of the phosphor became more uniform after both grinding and ultrasonic sieving methods. After processing, the phosphor with the diameter of 7 m shown fewer shifts on the color temperature coordinate δX. Owing to the degradation of the optical characteristics of the phosphor processed with grinding method, we finally choose the ultrasonic sieving method for final product assembly. It was found that color temperature coordinated can be effectively controlled and the shift of δX was less than the phosphor with large diameter and grinding process. Finally the yield rate could improve to 100%. Key words : phosphor, particle size, grinding, ultrasonic sieving
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Yang, Yi-Chen, and 楊以辰. "Investigation of optoelectronic characteristics of Cu/Al-doped ZnO prepared through sol-gel processing." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/28882770517229587401.
Full textAbstract:
碩士元智大學
化學工程與材料科學學系
105
Properties and energy levels of Al-doped ZnO (AZO), Cu-doped ZnO (CZO), and Cu/Al-doped ZnO (CAZO) crystals, were investigated. Metal-doped ZnO with different dopant compositions were prepared by sol-gel synthesis at 60 oC. Results showed that these ZnO samples were in a hexagonal close packing crystal structure and the grain sizes of the crystals decreased in the presence of the dopants. The resistivity of AZO was decreased because of the increase of carrier concentration and mobility, whereas, the resistivity of CZO and CAZO increased. The energy levels of the crystal samples were estimated and varied depending on the presence of different dopants in ZnO. The conduction band energy (Ec) and valence band energy (Ev) of AZO apparently shifted to higher energy levels, causing the increase of the bandgap energy (Eg) for AZO. The Eg of CZO was reduce with respect to ZnO because its Ec was significantly altered. The Eg of CAZO was widened because the Ev was significantly shifted by Al and the Ec was mainly varied by Cu.