Дисертації з теми "Low-temperature Techniques"
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Hopkins, S. C. "Optimisation, characterisation and synthesis of low temperature superconductors by current-voltage techniques." Thesis, University of Cambridge, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.604224.
Повний текст джерелаGeorgiacodis, D. N. "Low temperature ion-irradiation effects in silicon studied by ion-channelling techniques." Thesis, University of Sussex, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.304345.
Повний текст джерелаLopez-Calvo, Alfredo Manzanares Carlos E. "Vibrational spectroscopy in cryogenic solutions application of thermal lensing and Fourier transform techniques to the study of molecular C-H overtone transitions /." Waco, Tex. : Baylor University, 2006. http://hdl.handle.net/2104/4873.
Повний текст джерелаAbdullah, J. B. "The assessment of high temperature damage in 2.25 Cr - IMo low alloy steel using ultrasonic techniques." Thesis, Swansea University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.635833.
Повний текст джерелаSpalholz, Hans. "Development of Short Term Storage Techniques for Grafted Vegetable Seedlings." Thesis, The University of Arizona, 2013. http://hdl.handle.net/10150/293734.
Повний текст джерелаBeale, Andrew Michael. "Novel low temperature preparation methods for mixed complex oxide catalysts and their characterisation via in situ SR techniques." Thesis, University College London (University of London), 2003. http://discovery.ucl.ac.uk/1453143/.
Повний текст джерелаThankaraj, Salammal Shabi [Verfasser]. "Structural and morphological investigations of Poly(3-alkylthiophene) thin films prepared by low and room temperature casting and spin coating techniques / Shabi Thankaraj Salammal." Siegen : Universitätsbibliothek der Universität Siegen, 2012. http://d-nb.info/1024804259/34.
Повний текст джерелаKadri, Mohammed. "Formation à basse température et nouvelles techniques de caractérisations [sic] du disiliciure de tungstène WSi2." Grenoble 1, 1987. http://www.theses.fr/1987GRE10053.
Повний текст джерелаKermarrec, Edwin. "Nouveaux états quantiques de spin induits par frustration magnétique sur le réseau kagome." Phd thesis, Université Paris Sud - Paris XI, 2012. http://tel.archives-ouvertes.fr/tel-00783605.
Повний текст джерелаGrobler, Thelma. "Two-dimensional gas chromatography : a novel technique for iron low temperature Fischer-Tropsch selectivity studies." Master's thesis, University of Cape Town, 2008. http://hdl.handle.net/11427/5327.
Повний текст джерелаIncludes bibliographical references (leaves 158-178).
Fischer-Tropsch synthesis is a process that catalytically converts hydrogen and carbon monoxide into a large variety of hydrocarbons and oxygenated products. Over the years many researchers have attempted to describe the full product spectrum (ranging from C1 to C100+) but due to the complexity of the product and shortcomings of certain analytical techniques (or equipment) most researchers were only able to construct product distributions from extrapolations of data recorded from analysis of the C1 to C5 fraction of the Fischer-Tropsch product. With recent advances in analytical technology and the development of comprehensive two-dimensional gas chromatography (GCxGC) it may now be possible to analyze the complex Fischer-Tropsch products in a relatively short time while delivering good separation of even minor compounds such as oxygenates and branched compounds. The aim of this study was to investigate if two-dimensional gas chromatography (GCxGC) really results in improved separation and identification of compounds in the complex Fischer-Tropsch product spectrum and will lead to a more complete product distribution especially of the minor compounds such as branched hydrocarbons, ketones, aldehydes and acids. For this study GCxGC equipment, supplied by Zoex Corporation, was connected to a micro slurry phase reactor system to provide for both on-line gas analysis as well as off-line product analysis. GCxGC methods were developed to analyze the hot tail gas and oil products from Fischer-Tropsch synthesis. Thereafter a test sample (C6 to C30 oil product from Fischer- Tropsch synthesis process) was injected several times into both the GCxGC and 1D GC systems. The purpose of this was to compare the detection ability and accuracy of the two instruments.
Miura, Masashi, Masakazu Itoh, Yusuke Ichino, Yutaka Yoshida, Yoshiaki Takai, Kaname Matsumoto, Ataru Ichinose, Shigeru Horii, and Masashi Mukaida. "Effect of Sm/Ba substitution on the J/sub c/ in magnetic field of SmBCO thin films by low temperature growth technique." IEEE, 2005. http://hdl.handle.net/2237/6778.
Повний текст джерелаZheng, Hanguang. "Processing and Properties of Die-attachment on Copper Surface by Low-temperature Sintering of Nanosilver Paste." Thesis, Virginia Tech, 2012. http://hdl.handle.net/10919/42658.
Повний текст джерелаMaster of Science
Amro, Raed. "Power cycling capability of advanced packaging and interconnection technologies at high temperature swings." Doctoral thesis, [S.l. : s.n.], 2006. https://monarch.qucosa.de/id/qucosa%3A18552.
Повний текст джерелаXiao, Kewei. "A diffusion-viscous analysis and experimental verification of the drying behavior in nanosilver-enabled low-temperature joining technique." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/25137.
Повний текст джерелаPh. D.
Ichino, Yusuke, Yutaka Yoshida, Kouichi Inoue, Toshinori Ozaki, Yoshiaki Takai, Kaname Matsumoto, Masashi Mukaida, Ryusuke Kita, Ataru Ichinose, and Shigeru Horii. "Effect of BaZrO3 Addition and Film Growth on Superconducting Properties of (Nd,Eu,Gd)Ba2Cu3Oy Thin Films." IEEE, 2009. http://hdl.handle.net/2237/13894.
Повний текст джерелаPoole, Warren J., Matthias Militzer, J. Huang, S. C. Vogel, and C. Jacques. "The study of low-temperature austenite decomposition in a Fe–C–Mn–Si steel using the neutron Bragg edge transmission technique." Elsevier, 2007. http://hdl.handle.net/2429/397.
Повний текст джерелаVenclíková, Michaela. "Využití pěnoasfaltu v asfaltových směsích." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2018. http://www.nusl.cz/ntk/nusl-372058.
Повний текст джерелаHoubloss, Samir. "Detection thermique de l'absorption optique : developpement de la technique, informatisation, etudes d'elements 3d dans des materiaux iii-v." Clermont-Ferrand 2, 1988. http://www.theses.fr/1988CLF21078.
Повний текст джерелаCasado, Mathieu. "Water stable isotopic composition on the East Antarctic Plateau : measurements at low temperature of the vapour composition, utilisation as an atmospheric tracer and implication for paleoclimate studies." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLV058/document.
Повний текст джерелаIce cores enable reconstruction of past climates, from among others water stable isotopic composition (δ18O, δ17O et δD). On the East Antarctic Plateau, very cold temperature and low accumulation provide the longest ice core records (up to 800 000 years) but embrangle the interpretation of isotopic composition. First, reconstructions of temperature variations from ice core water isotopic composition are based on models used to describe the evolution of the isotopic composition of the vapour and of the condensed phase over the entire water cycle. These models have been developed during the last decades and depend upon precise determinations of isotopic fractionation coefficients associated to each phase transition and upon hypotheses to describe cloud microphysics.During the formation of snowflakes at low temperature, two types of isotopic fractionations need to be taken into account: equilibrium fractionation, associated to the vapour to ice phase transition and kinetic fractionation associated to the difference of diffusivity of the different isotopes. At low temperature, determinations of equilibrium fractionation coefficients present important discrepancies and have never been realised for temperature below -40°C. However, mean annual temperature at Dome C is around -54°C reaching -85°C in winter. For the diffusivities of the different isotopes, they have never been measured at temperature below 10°C. All these gaps result in important uncertainties on the link between isotopic composition and temperature, especially for cold and dry conditions such as encountered on the East Antarctic Plateau.Furthermore, because of the very low amount of precipitation, physical processes affecting the isotopic composition of the snow after the deposition of snowflakes can results in an important contribution to the isotopic budget. In order to estimate the impact of the post-deposition processes on the water vapour isotopic composition, it is necessary to characterise the isotopic fractionation at the snow/atmosphere interface for temperature down to -90°C.In order to improve isotopic paleothermometer performances, it is primordial to study processes affecting snow isotopic composition. Toward this goal, my Ph-D has been at the interface between monitoring of processes affecting isotopes, both in laboratory experiments and field studies, and instrumental development to push the limits of water vapour isotopic composition trace detection. On one hand, new developments in optical feedback frequency stabilisation applied for the first time to water isotopic composition monitoring provide performances beyond any commercial instrument and can be used for thorough processes studies. The laser frequency is stabilised by optical feedback from an ultra-stable cavity to the hertz level. Then, the light is injected in high performances cavity with a sensibility of 10-13 cm-1.Hz-1/2. This enables measuring isotopic composition with a precision below the ppm level.On the other hand, laboratory experiments have supported theories about isotopic fractionation associated to the vapour to ice phase transition and to kinetic fractionation linked to the difference of diffusivities of the different isotopes. Finally, these physical models have been collated to field measurements realised at Dome C in Antarctica, which are among the first water vapour and snow isotopic composition measurements realised inland Antarctica. These measurements show how important is the contribution of the sublimation condensation cycles to the snow isotopic composition budget on the East Antarctic Plateau
Lin, Yan-Tsang, and 林彥滄. "Process- and Temperature-Compensated Techniques and Solar-Powered Techniques of Low-Noise Amplifiers." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/95157027375063136087.
Повний текст джерела國立高雄師範大學
電子工程學系
101
This thesis proposes the process- and temperature-compensated techniques and the solar-powered techniques of the low-noise amplifier (LNA). For process and temperature compensation, a body-bias technique is used to compensate the RF parameters of the LNA. This LNA is designed and implemented using the 0.18 μm CMOS standard process. For process compensation, the variation in noise figure (NF) is reduced from 0.8 dB to 0.2 dB and the variation in gain is reduced from 5.33 dB to 0.2 dB. For temperature compensation, the variation in noise figure (NF) is reduced from 1.25 dB to 0.89 dB and the variation in gain is reduced from 1.06 dB to 0.35 dB. For solar self-powering, a 2.4 GHz LNA is designed and implemented using the 0.18 μm CMOS standard process for ZigBee applications. A solar panel with a regulator circuit directly converts solar power to the electrical power of the LNA, as required to provide green energy. Measurements of the solar-powered 2.4 GHz LNA are made, revealing that the NF is 2.91 dB, the gain is 10.89 dB, and the input-referred third-order intercept point (IIP3) is 0 dBm. A voltage of 0.6 V is supplied to the LNA and the power consumption is then 1.08 mW.
Lee, Shin-De, and 李信德. "Low Temperature Bonding Techniques for Sealing Teflon Based Microfluidic Devices." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/66478814280063664162.
Повний текст джерела國立中山大學
機械與機電工程學系研究所
100
Microfluidics emerged during the early 1990s with channel networks in silicon or glass. Microprocessing of these materials is labor-intensive and time-consuming, it requires sophisticated equipment in a clean room, and often involves hazardous chemicals. The subsequent use of polymer greatly simplified the fabrication of microchips and led to the rapid development of the field. Polymer such as poly(dimethylsiloxane) (PDMS), has other attractive properties, such as being elastic (easy to make efficient microvalves), permeable to gases, and compatible with culturing biological cells. Despite these advantages, applications of PDMS chips are severely limited by a few drawbacks that are inherent to this material: (i) strong adsorption of molecules, particularly large biomolecules, onto its surface; (ii) absorption of nonpolar and weakly polar molecules into PDMS bulk; (iii) leaching of small molecules from PDMS bulk into solutions; and (iv) incompatibility with organic solvents. To overcome all these problems, Teflon plastics seem to be the perfect solution. They are well-known for their superior inertness to almost all chemicals and all solvents; they also show excellent resistance to molecular adsorption and molecule leaching from the polymer bulk to solutions. However, Teflon has a high chemical inertness of the surface, which is restricted the bonding temperature (>260°C).It is not conducive to the low-temperature packaging process. This study presents a simple and rapid process for sealing Teflon-based microfluidic chip at a temperature of 140oC which is lower than typical bonding temperature of 260oC. A simple ammonium plasma treatment is used to enhance the surface energy of Teflon substrates such that the bonding temperature can be greatly reduced. Results indicate that the ammonium plasma treated Teflon substrates can be sealed using hot press bonding at a temperature of 140oC for 20 min. The measured iv bonding strength for the Teflon-based microfluidic devices is higher than those bonded at a reported temperature of 260oC for 60 min. It shows the measured contact angle for the Teflon substrates treated with different plasmas. Results indicated that the ammonium hydroxide plasma exhibited the best wettability property and the contact angle reached the minimum value of 45o after 5 min of treatment. The ESCA analysis showed the best Defluorination by ammonium plasma. The fluorine/carbon atomic ratio degraded from 1.96 to 1.10 by 5 minutes. The measured bonding strength for the Teflon substrates bonded with different surface activation protocols. Results showed that the bonding strength was enhanced upto 93% after the plasma treatment. The plasma treatment not only enhanced the bonding strength but also reduced the bonding temperature and time. The measured surface roughness only increased 15±5 nm (Ra) after the plasma treatment, which is acceptable for most applications in microfluidic systems. Finally, the fluorescence optical architecture and cross-chip successfully detected and isolated ΦX-174 fragment of DNA samples confirmed the Teflon substrate for the emerging microfluidic plastic chip. The developed method provides a simple and rapid way to fabricate Teflon-based microfluidic devices.
Chen, You Shen, and 陳宥伸. "Preparation of Perovskite Solar Cells Using Low-temperature Solution Processing techniques." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/f2tg2d.
Повний текст джерела長庚大學
光電工程研究所
104
Solar is a renewable energy, Power generation process does not produce greenhouse gases carbon dioxide emissions, for the protection of the environment is very helpful; from 2012 to the rapid progress of perovskite solar cells, compared with silicon solar cells, which have the advantages of low material cost, Preparation of solution method, low cost manufacturing process, and its photoelectric conversion efficiency of silicon solar cells is expected to catch up, many scientists have also invested in this research effort. Perovskite solar cells perovskite layer made way roughly divided into two types, one is to use the one-step production, is to methylamine iodide (MAI) with lead iodide (PbI2) both Moore and other dissolved proportion after DMF was spin-coated on a substrate; and a two-step rule is the first spin-coated on a substrate PbI2, then soaked after film or iodine drops methylamine grow perovskite crystalline; used in this experiment produced a two-step method. We found that the changed PbI2 standing time will affect their different deposition patterns, the extent of the longer standing PbI2 the aggregation of particles leading to greater perovskite crystal patterns will vary from can be observed on the XRD perovskite films of different PbI2 standing time in the (001) peak characteristic changes significantly, standing at the time when the minimum peak 150s, 150s on behalf of the use of standing time making PbI2 film with 30mg/mL of MAI has the best solution crystalline state. Our success to make efficiency of 10.57% perovskite solar cells, JSC of 16.85mA/cm2, VOC is 1.01V, F.F. of 61.9%, also after continuous measurements found in the first four days up to maximum efficiency 12.65 %. Discussion with the addition of lead iodide standing time of lead iodide with methyl iodide amine concentration both outside, in order to improve the stability of the device, we also try to join the mesoporous layer observation element of the performance, first we direct the dense layer on the ZnO production of mesoporous TiO2 layer, then a two-step method to create elements, we change the spin speed to create different mesoporous layer, only the most efficient battery JSC of 8.89mA/cm2, VOC can reach 1.04V, F.F. of 50.4% efficiency of 4.66%, showed that under these conditions we did not have better cell performance. In addition, we also try to use the TTIP and TiO2(P90) to two different solution volume ratio of production to replace the dense layer of dense ZnO layer found in full without adding TTIP conditions, cell efficiency of up to 7.94%, then this condition further change speed control different mesoporous layer film, you can then create the conditions 1500rpm efficiency of 10.39% of the element JSC up 16.82mA/cm2, VOC is 1.008V, F.F. was 61.3%.
Lu, Wei Xin, and 盧維新. "Application of low-temperature deposition and high-temperature rapid thermal treatment techniques on the fabrication process of silicon gate oxides." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/25388417596047777464.
Повний текст джерелаWang, Shen-De, and 王獻德. "Study on Fluorine Passivation Techniques and the Reliability for Low Temperature Polycrystalline Silicon Thin-Film Transistors." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/83465719750608671993.
Повний текст джерела國立交通大學
電子工程系所
94
In this thesis, various fluorine passivation techniques for fabricating high-performance and high-reliability polycrystalline silicon thin-film transistors (poly-Si TFTs) are proposed and discussed. In addition, the On-current (Ion) and Off-current (Ioff) instabilities of poly-Si TFTs under electrical stress are thoroughly investigated. At last, a new scheme by employing high-resolution scanning capacitance microscopy (SCM) is developed to scan the breakdown spots on oxide films. First, a process-compatible CF4 plasma treatment for fabricating high-performance solid-phase-crystallized (SPC) poly-Si TFTs is demonstrated. Using this technique, fluorine atoms can be introduced into poly-Si films to passivate trap states, and hence the performance of SPC poly-Si TFTs can be significantly improved. The fluorinated SPC poly-Si TFTs exhibit good subthreshold slope, low threshold voltage, and better On/Off current ratio. The fluorinated poly-Si TFT also shows approximately 22.8 % enhancement in the maximum field-effect mobility. Moreover, the CF4 plasma treatment also promotes the device’s hot-carrier immunity. Then, CF4 plasma treatment combined with excimer laser annealing (ELA) is proposed to fabricate high-performance ELA poly-Si TFTs. Fluorine can effectively passivate the trap states near the SiO2/poly-Si interface. With fluorine incorporation, the electrical characteristics of ELA poly-Si TFTs are significantly improved. The CF4 plasma treatment also improves the device reliability of ELA poly-Si TFTs with respect to hot-carrier stress, which is due to the formation of strong Si-F bonds. Another fluorine passivation technique is also proposed by adopting fluorinated silicate oxide (FSG) as a buffer layer. Experimental results reveal that the device performance, uniformity and reliability can be remarkably improved with appropriate fluorine content (2% to 4%) in the FSG layer. Then, the On-current (Ion) and Off-current (Ioff) instabilities of poly-Si TFTs are thoroughly investigated under various electrical stress conditions. The stress-induced device degradation is studied by measuring the dependences of Ion and Ioff on the applied drain/gate voltages. From the results, dissimilar variations of Ion and Ioff can be observed, which is attributed to the variances in the amount of trap charges in the gate oxide and the spatial distributions of trap states generated in the poly-Si channel. A comprehensive model for the degradation of Ion and Ioff in poly-Si TFTs under various electrical stress conditions is proposed. Finally, scanning capacitance microscopy (SCM), combined with atomic force microscopy (AFM), is employed to investigate the dielectric breakdown phenomena in SiO2 films. The localized breakdown spots can be clearly imaged by this technique. The breakdown spots exhibit signals with low differential capacitance (dC/dV) due to high conductivity. The diameters of these breakdown spots are from 6 nm to 13.5 nm. Moreover, according to the corresponding AFM images, their surface morphology shows little change after the occurrence of oxide breakdown.
Hu, Shen-Chih, and 胡慎知. "The Study of Resource Recycling of Sludge by Low-Temperature Co-melting and Surface Modified Techniques." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/33371822772130335997.
Повний текст джерела國立東華大學
材料科學與工程學系
101
Sewage sludge is produced by urban waste water treatment. Because of the perishable organic substances, sludge disposal without advanced treatment can produce public health problem. Lightweight aggregate synthesized with sewage sludge is a feasible method for sludge recycling and natural constructive materials saving, but the sintering temperature is always over 1000 oC to form melting glassy phase and large energy is consumed. This study focused on adding some low melting point compounds (H3BO3 and Na2CO3) as flux in order to lower the sintering temperature of artificial aggregates. Water adsorption, apparent porosity, bulk density, compressive strength, and soundness test were applied to evaluate the effect of experiment condition on the characteristics of synthetic aggregates. In addition, there were three other wastes which were used as raw materials for aggregates synthesis in this study, including sludge ash derived from sewage sludge, paper sludge and stone manufacturing sludge. As a result, all these industrial waste could be transformed to lightweight aggregates by thermal treatment and the characteristics of these aggregates were different in a reasonable range. According to the experimental design, sewage sludge was adjusted by adding SiO2 to make the SiO2/Al2O3 ratio of the conditioned sludge up to 4. When the flux of H3BO3 was used, 3 wt% of conditioned sludge of CaO was added to prevent the occurrence of black core phenomenon. Conditioned sewage sludge mixed with 13 wt% H3BO3 and 3 wt% CaO were heated at 400 oC for 0.5 hr and 850 oC for 1hr was followed to get highest compressive strength aggregate. The values of four primary parameters of aggregate (including water adsorption, apparent porosity, bulk density and compressive strength) were 3.88 %, 3.93 %, 1.05 g/cm3, 29.7 MPa. The flux was Na2CO3, the highest value of compressive strength of aggregates were got when sludge mixed with 16 wt% Na2CO3 and sintered at 400 oC for 0.5 hr; 900 oC for 1 hr. The values of the four primary parameters of aggregates are 1.36 %, 1.7 %, 1.26 g/cm3, and 27.7 MPa. Sewage sludge ash was also adjusted by adding SiO2 and the ratio of SiO2/Al2O3 was 4. The identical dosages of both H3BO3 and Na2CO3 were 22 wt% of conditioned ash. When the flux was H3BO3, the synthetic aggregates with high compressive strength were sintered at 900 oC for 15 min. When the flux was Na2CO3, the aggregates with higher compressive strength were sintered at 900 oC for 0.5 hr. The values of the four primary parameters of aggregates mentioned above were 5.43 %、5.15 %、0.97 g/cm3、29.2 MPa and 1.42 %、1.64 %、1.17 g/cm3、88.4 MPa respectively. Because the content of Si of paper sludge was too low, SiO2 was added to make the SiO2 content up to 12 wt% of the wet paper sludge. The dosage of H3BO3 was 18 wt% of the conditioned paper sludge and the sintering program was 890 oC for 30 min. The aggregates synthesized with this procedure have the lower water adsorption and the values of the four primary parameters of aggregates are 4.64 %, 2.77 %, 0.6 g/cm3, and 13.2 MPa. Lightweight aggregates can be produced from stone manufacturing sludge with 15 wt% of H3BO3. The sintering program was set for 850 oC 15 min. The water adsorption, apparent porosity, bulk density and compressive strength of the aggregates were 0.21 %, 0.35 %, and 1.67 g/cm3 and 66.9 MPa. Sewage sludge, sewage sludge ash and paper sludge were investigated to be adsorbent for Methylene Blue (MB, cationic dye) and Procion Red MX-5B (PR, ionic dye). Sewage sludge contained organic compounds with oxygen-rich functional group (such as humic substances) which can adsorb pollutants in the water. In order to improve the adsorption ability and filtration efficiency of sewage sludge, Fe3O4 was synthesized on the sewage sludge by hydrothermal method. Fe3O4 can not only act as an adsorptive site for ionic dye, but also decrease the specific resistance of sewage sludge by crystallization. The experimental results showed that ideal pH for modified magnetic sewage sludge to adsorb MB and PR were 6 and 3, and the isotherm adsorption was fitted well to Langmuir equation. The maximum adsorption capacity for MB and PR were 25.06 and 18.83 mg/g. Pseudo-first-order and pseudo-second-order models were utilized to realize the kinetic adsorption of MB and PR. The adsorption data of both dyes were fitted pseudo-second-order model well and the activation energy of MB and PR adsorption were 42.78 kJ/mol and 32.69 kJ/mol, respectively. The crystalline of Fe3O4 synthesized on sewage sludge improved the filtration efficiency of modified magnetic adsorbent and the filtration resistance was decreased from 1.34×107 s2/g to less than 0.08×107 s2/g. Different from sewage sludge, sludge ash was under thermal treatment and the organic compounds were oxidized to CO2 so that sludge ash particle possessed no organic functional group on the surface. In this study, ferrite process was also conducted on sludge ash and Fe3O4 can act as adsorptive site for ionic dyes because Fe3O4 can provide electrostatic attraction to ionic dyes. The zeta potential of Fe3O4 was positive in acid and anionic dye can be adsorbed. Similarly, that was negative in alkali solution and cationic dye can be adsorbed. As the result of adsorption, MB was well adsorbed in pH 9 and that for PR was 2.7 which corresponded to the zeta potential of modified magnetic sludge ash. The isotherm adsorption and kinetic adsorption of MB and PR were also investigated. For isotherm adsorption, the results were fitted Langmuir equation well and the maximum adsorption capacities of MB and PR were 22.27 mg/g and 28.8 mg/g. For kinetic adsorption, pseudo-first-order and pseudo-second-order models were utilized to examine the adsorption behavior and the results were fitted pseudo-second-order models well. The activation energy calculated from Arrhenius equation was 61.7 kJ/mol for MB and 9.07 kJ/mol for PR. Owing to paper sludge contained large amount of organic compounds such as fibers and lignin, it could be pyrolyzed to form activated carbon for dye adsorption. In this study, paper sludge was pyrolyzed under nitrogen atmosphere at 600 oC 1 hr. Then, sample was washed with 1 M HCl and DI water, and dried in an oven. The zeta potential measurement of adsorbent showed that the isoelectric point of paper sludge derived activated carbon was around 3 which meant PR should be adsorbed well below pH 3 and that of MB was in neutral or alkali solution. The effect of pH on adsorption, isotherm adsorption and kinetic adsorption were examined to realize the adsorption behavior of paper sludge derived activated carbon. The results of adsorption in different pH condition were conformed to the results of zeta potential. The data of isotherm adsorption experiment revealed that the adsorption behavior can be described by Langmuir equation well and the maximum adsorption capacities of MB and PR were 119.1 mg/L and 65.8 mg/L. Kinetic adsorption revealed that the adsorption of two dyes were fitted pseudo-second-order model well, and the activation energy of MB and PR adsorption were 8.66 and 2.47 kJ/mol.
Shye, Der-Chi, and 史德智. "Low-Temperature Processing Techniques Applied on Barium Strontium Titanate Films for the Applications of DRAM Storage Capacitors." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/85373278879314570415.
Повний текст джерела國立交通大學
電子工程系所
93
The characteristics of (Ba, Sr)TiO3 thin films, prepared by novel techniques of low temperature treatments, were systematically studied in this thesis. Pt/TiN/Ti/Si substrates were applied on each sample to simulate the real capacitor over bit-line (COB) structure of dynamic random access memory (DRAM). (Ba, Sr)TiO3 (BST) films were sputtered by radio frequency (RF) magnetron system with dual targets at low substrate temperature, lower than 450oC (340oC at sample surface), and the effects of the process parameters were also investigated. The work pressure, the sputtering gun power and the gas-mixing ratio are the important parameters in the BST film deposition. Material analyses and electrical testing show that the low temperature BST films are significantly affected by those process parameters. The O2/(Ar+O2) mixing ratio (OMR) is a most critical parameter during BST film sputtering. Plasma emission spectra indicate that the deposition rate declines at a higher OMR due to oxide formation on the target surface. The dielectric constant of the BST films can reach a maximum of 364 at 5% OMR. The ten-year lifetime of the time-dependent dielectric breakdown (TDDB) implies that the reliability of the capacitor can be enhanced at a higher OMR due to the compensation of oxygen vacancies and smaller grain sizes. Current-voltage analysis indicates that the leakage current of the Pt/BST/Pt capacitor is limited by Schottky emission (SE)/Poole-Frenkel emission (PF) at a lower/higher applied field, accordingly. The applied field boundary between SE and PF shifts toward higher field as OMR increases. Moreover, an energy-band model was proposed and this leakage mechanism was also discussed. Post low-temperature treatments were applied on the BST films to further improve their crystallinities and electrical properties. A novel process, KrF excimer laser annealing (ELA) at the wavelength of 248 nm, had been undertaken to implement BST films at a process temperature of 300o C to avoid the steep thermal gradient in thin films. The dielectric constant of the amorphous (α) BST film was remarkably enhanced from 80 to over 250 after ELA treatment. The optical testing and the heat conduction analyses indicate that the underlayer films and devices cannot be damaged during ELA treatment due to a very shallow light absorption depth (20 nm) of the BST film at the wavelength of 248-nm. Besides, the laser energy fluence and film thickness greatly influence the thermal conduction and the temperature distribution within the BST films. In the meanwhile, the as-deposited films revealed (mm0) preferred orientation, and, intriguingly, the preferred orientations changed into (m00) and (mmm) after ELA treatments. The optical and the high frequency properties may be affected by this preferred-orientation change. However, although the ELA can perform “shallow-depth annealing” for BST thin film, the degradation of upper surface is strongly influenced by the laser energy fluence. Hence, the leakage current will be significantly affected by the energy fluence of the laser. The leakage current of the ferroelectric film increases after sputtering process and post ELA treatment, but post oxygen plasma treatment can effectively improve the BST film surface to suppress the leakage at low processing temperature of 250oC. According to the analysis results in this thesis, the oxygen plasma treatment can effectively passivate the oxygen vacancies of BST films, decreasing the leakage currents. The leakage current can be reduced as many as two orders of magnitude under proper control of plasma conditions. The characteristics of the dielectric reliability, TDDB, can be also improved by this treatment due to the compensation of the surface oxygen vacancies. In addition, a nano-scaled chromium (Cr) layer is applied onto (Ba, Sr)TiO3 (BST) thin film capacitor as an inter-layer to enhance thermal stability of capacitance and suppress leakage current. Temperature coefficient of capacitance (TCC) using this BST/Cr/BST (200nm/2nm/200nm) multifilm can achieve 30% lower than that using BST mono-layer (400nm) film. Besides, the leakage current can be also greatly suppressed by applying this nano-scaled Cr layer onto BST thin film capacitor. TCC and leakage current behave as functions of Cr thickness, so the optimal properties can be obtained with the Cr thickness of 2nm. Microstructure analysis suggests that the interfacial continuity strongly influences the TCC and leakage property due to scattering centers and series capacitance formed at imperfect interface. The correlated mechanisms between electric and material properties are systematically investigated in this work. BST thin film can be the most promising candidate for Giga-bit generation cell capacitor, because the low temperature processes can be compatible to the IC’s integration. In this thesis, the optimal properties of the BST films can be obtained by adjusting process parameter, applying post treatments and using thermal stabilization structures to achieve thorough low-temperature processes.
Wang, jui-hao, and 王瑞豪. "Fabrication of Low-Temperature Poly-Si Thin-Films Using Hot-Wire CVD and Al-induced Crystallization Techniques." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/99574835223515040275.
Повний текст джерела國立中興大學
材料工程學研究所
93
The study utilized hot-wire chemical vapor deposition (HWCVD) which mixed different ratio of SiH4 and H2 to deposit Si-film rapidly and also used aluminum-induced crystallization (AIC) to fabricate high-quality polycrystalline silicon (poly-Si) films which served as a seed layer and accumulated large grain poly-Si films quickly above the seed layer. The purpose of the study was to investigate the change of AIC thin films due to different annealing time and temperature, and to further analyze characteristics by X-ray diffraction (XRD), Raman spectroscopy diffraction techniques, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Hall measurement of the seed layer that was produced by the AIC technique and poly-Si films on seed layer that were deposited by HWCVD. For analysis of each layer, the poly-Si film have been used to detect the crystallization and preferred (111), (220) and (311) orientation by XRD and Raman spectroscopy diffraction techniques which be stronger than AIC-film. The microstructures of each film were observed by SEM and TEM. It was found that the AIC of grain was approximately 1 µm and the Si layers formed on seed layer of grain (1 µm in size) can be obtained. However, the lateral grain size of poly-Si (deposited on seed layer) was larger than the poly-Si films deposited directly on a glass substrate by HWCVD. Since the Si-atoms deposit in the orientation of seed layer, the poly-Si would be obtained. As a result, high crystalline fractions (91 and 95%) and high electron mobility (22 and 18 cm2/V-s) of poly-Si films were obtained by using a combination of HWCVD and AIC techniques.
Krywko-Cendrowska, Agata. "Low temperature, electrochemical deposition of silicon based films and their characterization by electrochemical, spectroscopic and microscopic techniques." Doctoral thesis, 2014. https://depotuw.ceon.pl/handle/item/952.
Повний текст джерелаCelem pracy było elektrochemiczne otrzymywanie i charakterystyka fotoaktywnych w roztworach wodnych filmów SiOx w celu potencjalnego zastosowania ich jako fotoanod. Praca eksperymentalna obejmowała elektroosadzenie warstw SiOx i ich spektroskopową i mikroskopową analizę, fotoelektrochemiczną charakterystykę oraz optymalizację warunków nanoszenia (potencjał i czas nanoszenia, rodzaj substratu, stężenie prekursora SiHCl3) w celu zarejestrowania możliwie najwyższych gęstości fotoprądów w badanych układach. Filmy SiOx osadzane były na powierzchniach elektrod Au, Pt i Cu z roztworu węglanu propylenu (PC) z użyciem trichlorosilanu (SiHCl3) jako źródła krzemu. W związku z niskim przewodnictwem roztworu SiHCl3/PC, zastosowano 0.1 M bromek tert-butylo amoniowy (TBAB) jako elektrolit pomocniczy. Wykazano, że chemiczny skład osadów, ich grubość oraz fotoaktywność zależała od rodzaju substratu, stężenia SiHCl3 i wartości potencjału osadzania. Woltamperometria cykliczna (CV) używana była w celu określenia szerokości okna elektrochemicznego (trwałości) elektrolitu oraz określenia zakresu potencjału redukcji SiHCl3 w zależności od używanego substratu. Zakres redukcji SiHCl3 był różny w zależności od zastosowanej elektrody, jednak w każdym przypadku starano się tak dobrać wartość potencjału osadzania aby znajdowały się na początku, w centrum i na końcu zakresu sygnału. Grubość osadów wynosiła od 1 do 24 μm, przy czym największe wartości zaobserwowano dla osadów otrzymanych na elektrodzie Cu. Użycie technik elektrochemicznych, spektroskopowych i mikroskopowych pozwoliło na określenie i optymalizację warunków osadzania filmów tak, aby otrzymać warstwy SiOx możliwie jak najbardziej fotoaktywne i stabilne w roztworach wodnych. Warstwy SiOx otrzymane na Au i Pt charakteryzowały się fotoaktywnością n-typu (reakcja fotoutlenienia) podczas pomiarów fotowoltaicznych w roztworze organicznym, natomiast filmy utworzone na Cu wykazały zachowanie typu p (pochodzące od reakcji fotoredukcji) w roztworach PC. Fotoaktywność osadów w wodnym roztworze kwasu nadcholowego (HClO4) była typu n, niezależnie od tego, na jakiej elektrodzie lub przy jakiej wartości potencjału były one osadzone. Za pomocą technik FTIR i XPS wykazano, że w każdym przypadku po pomiarze fotogalwanicznym filmy nadal zawierały SiOx, a niekiedy także Si:H. Ze wszystkich osadzonych filmów najwyższą wartość gęstości fotoprądu (100 μAcm-2) zarejestrowano dla filmu otrzymanego na Au przy -2.7 V vs. Ag. Fotoprąd zaobserwowany w wodnym roztworze HClO4 mógł pochodzić zarówno z fotowydzielania tlenu (O2), jak i z procesu fotokorozjii filmu, na przykład utlenienia SiOx do krzemionki (SiO2). W celu rozróżnienia tych dwóch procesów porównane zostały wartości ładunków potrzebne do ich realizacji z ładunkiem fotoprocesu zachodzącego w układzie. Wykazano, że reakcja fotoutlenienia zaobserwowana w toku pomiaru fotoelektrochemicznego w wodnym roztworze pochodziła od ciągłego fotowydzielania O2. W rozprawie poruszone były również kwestie mogące negatywnie wpływać na wartości uzyskiwanych gęstości fotoprądów takie jak degradacja mechaniczna (na przykład na etapie suszenia osadu) lub też ewentualna niedoskonałość kontaktu omowego pomiędzy elektrodą a półprzewodzącym osadem SiOx. W toku niniejszej pracy po raz pierwszy zademonstrowano, że warstwy SiOx elektrochemicznie osadzone w roztworze organicznym były fotoaktywne w roztworze wodnym. Zaobserwowany zysk energetyczny uzyskany przy użyciu oświetlenia wynosił około 1.3 V. Zaprezentowane wyniki otwierają możliwość konstrukcji tanich i wydajnych fotoelektrod opartych na Si i zastosowania ich w ogniwach fotogalwanicznych (tzw. ogniwach mokrych).
"Analyzing Techniques for Increasing Power Transfer in the Electric Grid." Master's thesis, 2012. http://hdl.handle.net/2286/R.I.15926.
Повний текст джерелаDissertation/Thesis
M.S. Electrical Engineering 2012
Hayes, Briana. "Elimination of parasites using non-thermal and low temperature techniques and effect on chemical and sensory quality of raw oysters." 2006. http://purl.galileo.usg.edu/uga%5Fetd/hayes%5Fbriana%5Fk%5F200608%5Fms.
Повний текст джерелаSerrazina, Ricardo Nazaré. "Flash sintering of lead free perovskite oxides towards sustainable processing of materials for energy and related applications." Doctoral thesis, 2021. http://hdl.handle.net/10773/32637.
Повний текст джерелаPiezoelétricos como o K0.5Na0.5NbO3 (KNN) têm uma importância emergente devido à sua natureza livre de chumbo e variada aplicabilidade em componentes como sensores, atuadores, dispositivos de recolha de energia, biossensores, etc. No entanto, o KNN monofásico continua a ser difícil de produzir devido à elevada temperatura e tempo associados ao processo de sinterização convencional. Este doutoramento propõe a utilização de um método alternativo de densificação, a sinterização FLASH, que acima de uma condição limite promove a densificação repentina de cerâmicos por uma combinação de ambiente do forno (atmosfera e/ou temperatura) com a aplicação de campo elétrico diretamente no material. Existem vários mecanismos reportados para explicar a sinterização FLASH. O aquecimento por efeito de Joule é um dos mais reportados e aceites, mas também têm sido sugeridos mecanismos envolvendo a criação e movimento de defeitos por efeito do campo elétrico. Uma compreensão clara do fenómeno continua por ser apresentada, mas muito provavelmente a sinterização por FLASH resulta duma combinação destes dois efeitos, sendo que a energia e condutividade das superfícies das partículas desempenham um papel fundamental. Este trabalho pretende explorar a sinterização por FLASH de cerâmicos, mas também estudar os seus fenómenos fundamentais, mais especificamente, na sinterização FLASH de KNN. O objetivo último deste trabalho é o desenvolvimento de processos de sinterização de cerâmicos que operem à temperatura ambiente, contribuindo para a economia energética e sustentabilidade da indústria cerâmica. A utilização de ferramentas de Modelação por Elementos Finitos (MEF, ou FEM) permitiu estudar o efeito da orientação das partículas na geração de calor por efeito de Joule durante o FLASH, enquanto a modelação da distribuição temperatura local e respetivos gradientes térmicos foram usados para explicar tensões induzidas em cerâmicos densos. A produção de pós de KNN com diferentes tamanhos e pureza permitiu estabelecer a sua relação com a temperatura de FLASH (TF). Em consequência, o estabelecimento de um ciclo térmico apropriado, antes da aplicação do campo elétrico, permitiu obter cerâmicos de KNN com densidade relativa de 95%. A ligação entre os parâmetros de FLASH, como densidade de corrente e tempo, foi determinada, e a relação com a densidade final e tamanho de grão dos cerâmicos foi estudada. Estudos em TEM e FEM permitiram propor um mecanismo para a sinterização por FLASH de KNN, em que o fluxo de corrente pelas superfícies das partículas promove uma fusão parcial nos seus contactos e o rearranjo para a remoção de poros e densificação do compacto. De forma a permitir um decréscimo acentuado na TF do KNN, a sinterização FLASH assistida por atmosfera foi apresentada, e a temperatura foi diminuída para TF ≈ 265 ºC. No entanto, a densificação final foi limitada aos 79%. As propriedades ferroelétricas e dielétricas do KNN sinterizado por FLASH foram estudadas e comparadas com as de cerâmicos sinterizados convencionalmente. Um desempenho semelhante entre ambos foi obtido após um tratamento térmico para cura de elétrodos. No entanto, uma análise detalhada mostrou que as propriedades são afetadas pelo processo de FLASH em cerâmicos tratados ou não termicamente. Este trabalho apresenta uma contribuição clara no desenvolvimento da sinterização FLASH de cerâmicos, especificamente, no piezoelétrico KNN.
Programa Doutoral em Materiais e Processamento Avançados
Fernandes, Bruno João Baptista. "pMOSFET fabrication using a low temperature pre-deposition technique." Master's thesis, 2016. http://hdl.handle.net/10362/20677.
Повний текст джерелаSheu, Jong-Long, and 許忠龍. "Deep Level Characterization of Low-Temperature GaAs by Photoreflectance Technique." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/08582353000214100877.
Повний текст джерела國立交通大學
電子物理系
87
Photoreflectance (PR) spectroscopy is an optical and non-destructive technique and is widely used to characterize electronic properties of semiconductor materials and structures. We applied PR method to measure the deep levels of low-temperature grown GaAs samples. By analyzing the transient response of PR spectrum amplitude to the modulation frequence, we can acquire the time constants of deep levels at various sample temperatures. The Arrhenius plot relating the measured time constants and sample temperatures provides the information of the ionization energies and carrier-capture cross-section areas of deep levels. In this study, we characterize the deep levels of GaAs grown at 250 by molecular beam epitaxy (MBE) technique. By using this optical deep level transient spectroscopy (DLTS) technique, we found three deep levels along with the sample. The ionization energies of these deep levels are 0.657, 0.591, and 0.0587eV, respectively. The deep levels with 0.591 and 0.657eV ionization energies are attributed to the As precipitation and As antisite in the low-temperature GaAs sample, respectively. The 0.0587eV-related deep level has not yet been reported in the literature. Although the factor causing this deep level was not analyzed , we are confident on the validity of our measurement data which are partially consistent with possible known data. In summary, we demonstrated the versatile power of PR technique to characterize the electronic properties of semiconductors. By using the PR technique to perform the optical DLTS, we found some special deep level which was not be identified by other conventional DLTS system.
Lin, Pu-Chou, and 林莆洲. "Low-temperature Technique for High-efficiency Perovskite Hybrid Photovoltaic Devices." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/84984263513403614102.
Повний текст джерела國立中山大學
物理學系研究所
104
Due to the development of technology and gradual depletion of fossil fuels, the energy issue has received wide attention in this century. Solar energy is one of the best choices. Among many types of solar cells, perovskite solar cells suddenly appear on the horizon and the power conversion efficiency has been improved from 3 % to over 20 % in just 6 years. This makes many scholars who originally study in polymer and dye-sensitized solar cells start doing research about perovskite PVs. Halide perovskites have recently emerged as promising materials because of low-cost and high-efficiency. In this study, we develop a new method, Low Pressure Proximity Evaporation Technique (LPPET), combined with Solution Process (SP) to fabricate planar sandwich-like perovskite thin films. We also optimize the methods to improve the power conversion efficiency of the devices. Zinc oxide is widely used in polymer solar cells because of its good electron conductivity and high light transmittance. As a results, we first applied solution processed zinc oxide based on inverted-structure and a simple two-step solution process to fabricate perovskite PV cells. We modified the concentration of CH3NH3I solution to improve the efficiency. We analyzed the effect of interface morphology between perovskite and ZnO and finally, gained a PCE of 13.44 %. Because two-step process is very susceptible to the atmosphere and the formation of perovskite is too quick that causes perovskite grains small and messy, we developed a new method, called Low Pressure Proximity Evaporation Technique (LPPET) to fabricate perovskite layer. At first, we investigate two layered perovskite devices. In order to achieve complete formation of the bottom PbI2 and avoid the excess deposition of MAI on surface, we bring up an idea of using solution process along with LPPET to form a sandwich structure of MAI/PbI2/MAI. However, due to poor thermal stability of the perovskite layer, we found the LPPET process is different to be exercised on ZnO substrate. With appropriate LPPET parameters, we got a PCE of 11.29 % and a very good short-circuit current density of 18.38 mA/cm2. After that, we optimized LPPET process on traditional-structure perovskite PV devices. We found that the annealing step of sandwich-like perovskite layer is the most important factors to get best quality devices. The best crystallization and structure of perovskite could be obtained at 160℃, 35 minutes PbI2 annealing. Consequently, with adequate parameters of LPPET, we achieved efficiency of 15.52 % and large Jsc, 23.91 mA/cm2, also others good electric properties. For a low temperature process under whole atmosphere or under vacuum condition, this is a breakthrough of the perovskite solar cells and mass production.
Tseng, Huan-Chun, and 曾煥均. "Characterization of Low Temperature Poly Silicon TFTs with Laser Crystallization Technique." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/82450430811591421675.
Повний текст джерела國立交通大學
電機資訊學院碩士在職專班
93
It was extensively discussed the high-performance low temperature polycrystalline silicon (LTPS) application in monitor. In this thesis, many processes of crystallization means were discussed and the characterization of low temperature polycrystalline silicon (LTPS) thin film transistors (TFTs) were studied, in which the HF with the concentration of 0.1 percent was utilized by pre treatment clean process. Many methods and techniques had been proposed to further improve the performance of LTPS TFTs, which include means of prior clean treatment of amorphous silicon thin films, while most of the effort was focused on crystallization of amorphous silicon (a-Si) thin films. First, the electrical characteristics of LTPS TFTs fabricated by excimer laser annealing (ELA) of a-Si thin films which was used different pre treatment processes. From the results of material analysis and device characterization, the relation between electrical characteristics of LTPS TFTs and pre treatment processes conditions with laser annealing conditions had been identified. It was found that caused the surface oxidation of a-Si thin films by pre treatment process and laser energy density had a deep influence on the resulting poly-Si grain structure and electrical characteristics of LTPS TFTs. It was included the different methods of pre treatment process, the first method is surface cleaning with O3 water which concentration was 20ppm, the second method was surface cleaning with H2O2 water which concentration was 30%, the third method was surface cleaning with UV light exposure which wave length was 254um, and all of these methods can advance the surface oxidation of a-Si thin films, it had the difference at long time or short time treatment. When surface of a-Si thin films was completely oxidized by pre treatment process then treated by ELA, the LTPS thin films will be fabricated with grain size about 0.3um, grain shape like square and uniform distribution on surface. In this situation, the LTPS TFTs fabricated by ELA with optimization laser energy density, the field effect mobility of 130 and 90 cm2/V*s could be achieved for n-channel and p-channel ELA LTPS TFTs, respectively. The thresholds voltage had different shift owing to the difference surface oxidation on a-Si thin films. Changing laser scan frequency and energy couldn’t improve the crystalline quality and uniformity of crystallized poly-Si thin films and electrical characteristics of LTPS TFTs. In different ambiance of ELA crystallization had different efficiency, before mention the process of ELA crystallization had ambiance of N2 gas, now the concentration of low O2 with 2000ppm was utilized in ELA crystallization ambiance. From the results of material analysis, the LTPS thin films fabricated by ELA crystallization in ambiance of low O2 concentration had surface roughness like before mention process, the maximums surface roughness was about 80nm and average surface roughness was about 9nm, but the shape had some difference, the LTPS thin films surface roughness of low O2 concentration status had the shape like the cylinder in which the position was grain boundary and potential barrier was larger than grain area. The cylinder top surface were close to the gate bottom, when gate applied the forward bias, it would enhance the high electric file near the gate then induced the average thresholds voltage degradation. LTPS TFT’s fabricated by ELA crystallization in ambiance of low O2 concentration had lower thresholds voltage than N2 ambient condition, the thresholds voltage of +2 and –2 V could be achieved for n-channel and p-channel ELA LTPS TFTs, respectively. At last part of this thesis, the crystallization of continuing wave laser (CW laser) technology would be discussed. Crystallization of amorphous silicon (a-Si) thin films utilized the wavelength 532nm of CW lasers with different power and scan speed. Many factors of influence for grain size were discussed. It included the speed control in stage with different power during laser scanning; front and backside scan on substrate at different scanning speed. Owing to the laser beam energy distribution was the Gauss shape and laser beam size was affected by focus lens and laser power, we employ the focus lens with focus 600mm and focus the laser beam on substrate where the beam diameter was about 150um, when laser power more high the diameter more long. The LTPS thin films were fabricated by CW laser with grain size about 3um, grain shape like long bulk and large grain was aggregated in center area of laser beam on crystallization surface and the LTPS TFTs fabricated at large grain size area, the field effect mobility of 298 and 210 cm2/V*s could be achieved for n-channel and p-channel LTPS TFTs, respectively. The threshold voltages were shifted to 7V owing to the crystallization ambiance was atmosphere.
Yang, Meng-Syuan, and 楊孟璇. "Study of Amorphous ZnO:Al Thin Films by Low-Temperature Sputtering Technique." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/5pt426.
Повний текст джерела國立中山大學
物理學系研究所
97
Aluminum doped zinc oxide AZO has been studied for 20 years. It can improve thin films’ thermal stability and transparency in visible range .However AZO is not as good as ITO in conductivity and transparency, that’s why the application of AZO is only limited in few fields. This is because the nature limit of ZnO. Because part of doped Al forms Al2O3 instead of sits on Zn sites, that enhances light and carriers scattering and suppresses the optical transparency and electric conductivity. This study is plane to take advantage of amorphous properties, that may be achieved try grown films at liquid Nitrogen temperature, in which the distribution of Al and Zn will be very uniform and the solubility of Al will be high. ZnO:Al thin films is grown on glass substrates at low temperature by Radio frequency magnetron sputtering system. Low-temperature deposition is done in order to deposit amorphous thin films (ceramic targets ZnO contained 2wt.% Al2O3). The Al3+ in place of Zn2+ should be uniformly distributed in the thin films because of amorphous structure. It expects to find the best deposition condition under a fixed target-to-substrate distance (10cm) by varying growth, such as the deposition mode, PF plasma power and working pressure. AFM, XRD (grazing incident x-ray diffraction) and N&K analyzer were used to measure the thin surface morphology, structure, thickness and transmittance, respectively. The colors of the thin films are very different dependent on the modes of deposition. The low sputtering rate by lower RF power and high working pressure is the key to successfully grow amorphous ZnO:Al films. The amorphous ZnO:Al thin films (a-5) are deposited under 100W of RF power and 50mTorr of working pressure. The transmittance of the assembly of ZnO:Al thin films/glass substrate is the same as glass substrates which inducates the transmittance of films is far above 90%. However, the amorphous ZnO:Al thin films are poor conductor . We also tried to improve it by the post-annealing of ZnO:Al thin films in 2% hydrogen atmosphere. It is found to be not successful.
Kumar, Vikash. "Sb2Se3 thin-film solar cells via low-temperature thermal evaporation technique." Doctoral thesis, 2022. http://hdl.handle.net/11562/1069306.
Повний текст джерелаChang, Chih-Pang, and 張志榜. "Investigation of Crystallization Technique for Low-Temperature-Processed Poly-Silicon Thin-Film-Transistor." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/895v2a.
Повний текст джерела國立虎尾科技大學
光電與材料科技研究所
93
The use of low-temperature processed polycrystalline silicon thin-film transistors (LTP poly-Si TFTs) as pixel active elements and in peripheral driver circuits has been an important issue in the development of active-matrix flat panel displays (AMFPDs). This thesis studies a number of crystallization techniques for the high performance LTP poly-Si TFTs to achieve system on panel. Firstly, we propose solid-state continue-wave laser (CW-laser) to crystallized poly-Si films, the distinction of excimer laser, CW-laser possessed high stability, reliability, durable and low-cost. In this way, we used laser scanning speed and energy to analysis a status of grain lateral growth and crystallizes mechanism for various condition, furthermore, we succeed to crystallize great grain size more than 10 μm. To compare excimer laser crystallization (ELC) and Sequential lateral solidification (SLS), CW-laser don’t needed extra procedure to carrier out large grain size. On the other hand, solid-phase crystallization (SPC) had better uniformity but require to long annealing time to crystallized;Therefore, we suggested NH3 plasma treatment at server times before crystallized to shorten crystallization times, in this experiment, we have accomplished shorten crystallization times for NH3 plasma treatment, the novel crystallization method to compared the conventional process (SPC 15 hours) just require 2 hours for SPC to demonstrate NH3 plasma treatment efficiently shorten SPC annealing times and improvement electrical characteristics.
吳巧慧. "Characterization of application low-temperature BGe ion implantation technique in fabrication shallow-semiconductor devices." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/73066974397620512877.
Повний текст джерелаChen, Yu-shiang, and 陳裕翔. "Simulation Characteristics of Surface Acoustic Wave Device Packaged Using Low Temperature Cofired Ceramic Technique." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/06082929939022140304.
Повний текст джерела義守大學
電機工程學系碩士班
93
Recently, as fast developing in global telecommunication and personal communication getting matured, wireless communication industry tends to become more and more activating. Everyday various products related to telecommunications come to market. In general, those products, no matter they are system level or component level, must satisfy high frequency, miniaturization, and modulization. Because surface acoustic wave (SAW) device could not to integrate on silicon wafer to this day, only low temperature cofired ceramic (LTCC) technology offers a platform to integrate components into a miniaturized module and happens to be coincident with this trend. Hence, this thesis studies the characteristics of a SAW filter that was packaged using LTCC technique. First, the process of LTCC technology was overviewed. Then, the characteristics of a SAW filter packaged by LTCC technique was simulated using two different methods, one is by commercial 3D EM wave simulator (High Frequency Structure Simulator, HFSS) and the other is by a high frequency circuit simulator Ansoft Harmonic. The matching circuits for the SAW filter were as embedded into the package by LTCC. The simulation results show a good agreement by both methods. The technology used in the thesis provides a convenient way to evaluate the performance of SAW devices after packaged with LTCC process.
Chen, I.-Hui, and 陳怡蕙. "The Development of Observation Technique Using Transmission Electron Microscopy for Liposome at Low Temperature." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/595e62.
Повний текст джерела國立臺北科技大學
材料科學與工程研究所
103
In the past 30 years, cryo-transmission electron microscopy (cryo-EM) technology has been developed in many aspects for the applications on observing biological and medical specimens. Cryo-EM has been proven to be able to analyze some protein structures Cryo-EM allows users to quick-freeze the bio-samples in vitrified ice, observe the sample under the near-native condition, thus is a powerful tool to understand the samples in the native liquid phase. However, during cryo-EM operation, the high energy electron beam could quickly damage the ice sample. Therefore low-dosage imaging technique is usually used for cryo-EM. Even so, taking an image for a long exposure time could easily result in damaging on the icy bio-samples. Adding some sugar into bio-sample solution before TEM sample preparation was known to preserve the bio specimen better against the damage caused by the electron beam. This work aims for studying the effect of trehalose addition on preserving bio-samples under cryo-EM operation. Liposome was used as the bio-specimens for this study. In this work, various concentrations of trehalose solution were mixed with liposome solutions and made into cryo-EM specimens, then were taken images under different conditions of electron dosages used. The results show that trehalose addition is in fact effective in slowing the electron beam damaging occurring time on the cryo-EM specimen. This finding could be useful for practical applications of cryo-EM operation.
Lan, Che-wei, and 連哲緯. "The Low-Temperature Bonding Technique for Plastic-Based Microfluidic Chips and its Applications for Micromixers." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/25260062919662294167.
Повний текст джерела國立中山大學
機械與機電工程學系研究所
92
Abstract A new technique for bonding of polymer micro-fluidic devices has been developed. This method can easily bond biochips with complex flow patterns and metal layer. Above all, using a patterned glass, the micro-channel structures on Poly-Methyl Meth-Acrylate (PMMA) substrates were generated by one-step hot embossing procedure. In contrast with the traditional thermal bonding, this paper presents low-temperature and low-pressure packaging for polymer micro-fluidic platforms. Furthermore, the disposable plastic biochip has successfully been tested by the measurement of tensile strength and surface roughness. This paper also reports details of the passive and active micro-mixers. According to experimental and numerical investigations, the mixing performance of passive micro-mixers is expectably to be found. In addition, to quantify the mixing concentration distribution in the micro-channel, it has been demonstrated by launching the image analysis programs. The bonding efficiency of the solvent is twenty four times as strong as thermal bonding efficiency.
Chen, Tang-Yuan, and 陳瑭原. "Low-Temperature Bonding Technique for Plastic Microfluidic Chips and its Applications on Plastic Diffuser Micropumps." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/07719197619420033940.
Повний текст джерела南台科技大學
機械工程系
94
A new technique for bonding of polymer micro-fluidic devices has been developed. This method can easily bond biochips with complex patterns. By using a patterned Ni mold, the micro-channel structures on Poly-Methyl Meth-Acrylate (PMMA) substrates were generated by one-step hot embossing procedure and bonding of low temperature. In contrast with the traditional thermal bonding, the method presents low-temperature and low-pressure packaging for polymer micro-fluidic platforms. Furthermore, the tensile strength of the disposable plastic biochip was 179 kgf., which is 2 to 15 times greater than that of conventional methods. This paper also applied this technique on plastic diffuser micro-pumps, based on piezoelectric actuation. The pump was made of -PMMA, and the diameter and depth of the pump chamber was 6 mm and 200 mm, respectively. The working fluid was non-degassed de-ionized (DI) water. The flow rate of 53.6 ml/min was obtained at a 100 Vpp and 400 Hz square wave drivin g signal.
Chung, Chien-Chen, and 鐘健禎. "Study the Ultrafast Dynamics of High-Tc Superconductor at Low Temperature by Femtosecond Pump-Probe Technique." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/06779363552955463291.
Повний текст джерела國立交通大學
電子物理系
86
We have preformed a series of transient reflectivity(△R/R) measurements on oxygen-controlled YBCO thin films at different temperatures. A home-made femtosecond pump-probe system including a passively mode-lock Ti:sapphire laser and a continuous transfer cold finger cryostat were used for these measurement. The △R/R curves versus delay time of the oxygen-rich YBa2Cu3Ox (x=6.95) film for temperature ranging from 120K to 20Kwere different from those reports previously. The difference may due to the fact that they used different photon energy (~2eV) for the measurements and the drastically changes of density of states near Fermi level caused by pump beam could be probed. We also find the relaxation time has an abrupt change and become longer at superconducting state for oxygen-rich film while the relaxation time increases slightly with decreasing temperature for oxygen-deficiency (x=6.0) film. Additionally, we also measured the transient differential reflectivity of PBCO thin film. The sign of △R/R at room temperature is positive but it has a tendency to become negative at 240K and finally becomes negative below 220K. The change in sign if △R/R may due to the width of charge-transfer gap decreases when the temperature decreases.
Yang, Janne-Min, and 楊建民. "Investigation on the Formation Mechanism of Ultra-fine Zn-ferrite Powders at Low Temperature (<500℃) by Tartrate Technique." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/67347728940886342337.
Повний текст джерела國立成功大學
資源工程研究所
90
In the nonconventional preparation of spinel ferrite powders, the pyrolytic decomposition of precursors often occurs through multi-stage transformation paths, which involve different metastable intermediate phases. The present investigation deals with the synthesis of nano-sized zinc ferrite powders using the tartrate precursor technique. The focus of this investigation is to study the development of the intermediate phase during the decomposition of precursor, as well as the formation mechanism of zinc ferrite. Accordingly, the nano-sized zinc ferrite powders can be obtained at low-temperature (< 500℃) in this study. Characterizations of the various experimental products have been conducted as: (i) thermal behavior by DTA/TG, (ii) crystalline phase determined by XRD and TEM method, (iii) crystallite and particle sizes measured by Scherrer formula-XRD powder method, BET surface area diameters, and TEM, and (iv) magnetic properties and electronic structure of Zn conducted by SQUID and XPS techniques. The experimental results are given as follows: 1.The thermal reaction sequence during the precursor decomposition to synthesize zinc ferrite powders as performed in this work can be noted as follows: Step 1: Decomposition of the tartrate precursor Zn1Fe2-tartrate precursor 2/3Fe3O4+ZnO Step 2: Oxidation of Fe3O4 2/3 Fe3O4 +1/6O2 γ-Fe2O3 Step 3: Formation of inverse spinel Zn-ferrite γ-Fe2O3+ZnO (Fe3+)A[Zn2+Fe3+]BO2-4 Step 4: Inverse-normal spinel transformation (Fe3+)A[Zn2+Fe3+]BO2-4 (Zn)A[Fe2]BO2-4 2.The intermediate phase, Fe3O4, could not effectively react with ZnO to synthesize zinc ferrite at low temperature. The key step of preparation of ultrafine zinc ferrite powders by tartrate technique is the preheating process, in which the precursor is thermally treated between 300°and 400℃ for several hours to ensure complete conversion of the Fe3O4 into γ-Fe2O3. Therefore the ultrafine and mono-phase ZnFe2O4 can be obtained at low temperature by preventing the formation of α-Fe2O3 via preheating process. 3.It has been proven that the octahedral sites are preferentially exposed on the spinel surfaces. The γ-Fe2O3 is a cubic spinel, chemical formula of which is (Fe3+)[Fe3+5/3□1/3]O4, where □ stands for the vacancy of cation and distribution on the octahedral sites. Thus the γ-Fe2O3 can provide the cation vacancies on octahedral sites for Zn2+ ions diffusing into the octahedral-structured clusters, and then forming the inverse spinel zinc ferrite. The model of reaction mechanism between γ-Fe2O3 and ZnO is also built-up from the experimental results.
Hsieh, Chia-Chen, and 謝佳真. "The Study of The Low Temperature Flip-Chip Package by Applying AlGeSn-Based Transient Liquid Phase Bonding Technique." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/em95pz.
Повний текст джерела國立虎尾科技大學
電子工程系碩士班
101
In this study, the films are proposed that can be apply for low-temperature flip chip package by transient liquid phase bonding as AlGeSn-base. The AlGe/Sn films are deposited by thermal evaporation. And then the sample is placed in the vacuum environment for thermocompression bonding. In this experiment, use to the different film thickness ratio of AlGe and Sn for 280oC~350oC bonding, TAlGe:TSn=1:1, 2:1, 3:1, respectively. To find the best parameters, graphically produced, LED flip chip package and electrical measurements, after shear stress testing, SEM, EDS, and XRD analysis. The results show, the AlGeSn film will have the dendritic structure on the surface and phase separation after bonding at 350oC. TAlGe:TSn= 2:1 after bond at 300oC and 350oC, TAlGe:TSn=3:1 after bond at 350oC for 60min with the best of the shear strength. The XRD analysis, the main diffraction peak is Sn(200), the relative intensity of Ge(111) is between 0.4 to 0.6,and Al(111) is between 0.1 to 0.2. In LED flip chip package, it have the high forward voltage for 4.49V, and increase the thickness to about 4.5μm, the forward voltage drop of 4.7% under 20mA.