Tesis sobre el tema "Nanospheres Lithography"
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Perotto, Giovanni. "TWO DIMENSIONAL SELF ASSEMBLY OF NANOSPHERES, A VERSATILE METHOD FOR NANOFABRICATION". Doctoral thesis, Università degli studi di Padova, 2010. http://hdl.handle.net/11577/3422011.
Texto completoIl campo delle nanotecnologie è uno dei più innovativi e multidisciplinari della ricerca moderna. Sempre pi`u numerose diventano le tecniche per manipolare la materia su scala nanometrica, modificando così le proprietà fisico, chimiche e morfologiche a livelli mai raggiunti prima. Alla nano scala la manipolazione morfologica è accompagnata dal cambiamento delle proprietà che smettono di essere intrinseche della materia ma diventano dipendenti da altri fattori come la forma, la dimensione e l’ambiente in cui le nanostrutture sono immerse. Uno dei casi più eclatanti è il colore dell’oro e dell’argento quando sono sottoforma di particelle nanometriche. L’oro, ad esempio, può essere di colore rosso-vino, verde, blu e nero, semplicemente cambiando la forma o l’ambiente attorno ad esso. Manipolando la materia opportunamente possono comparire nuove proprietà come la trasmissione della luce attraverso aperture che sono molto più piccole della lunghezza d’onda della luce, dando la possibilità di ottenere il controllo della propagazione della luce ad un livello molto intimo. Si può capire quindi come per poter sfruttare le enormi potenzialità offerte dalle nanotecnologie sia importante avere tecnologie di fabbricazione che permettano un preciso controllo nella produzione di oggetti nanometrici o con strutture nanometriche. Le tecnologie al momento disponibili che permettono di creare strutture con precisione molto elevata (pochi nanometri) sono tecnologie ”seriali” come l’Electron Beam Lithography o il Focused Ion Beam. Queste tecniche sono limitate alla produzione di un oggetto alla volta e quindi comportano costi elevati e lunghi tempi. Le tecnologie ”parallele” derivano dall’industria dei semiconduttori e sono tecniche litografiche che hanno come limite la risoluzione della luce utilizzata ( 200nm). In questo lavoro di tesi si cercherà di dare risposta alla domanda di tecniche di fabbricazione di strutture nanometriche utilizzando una tecnica che abbia le seguenti caratteristiche: • quickness • low cost • ability to synthesize very small nanostructures • reproducibility • easy implementation Si è scelto di utilizzare la capacità della materia di organizzarsi spontaneamente in strutture ordinate. In particolare si è sfruttata la tendenza di nanoparticelle sferiche di polistirene ad impaccarsi in strutture compatte ed ordinate costituendo dei ”cristalli colloidali”. Un singolo strato di nanosfere autoassemblate è una struttura interessante perchè presenta dei pori tra le particelle di forma e dimensioni ben definite, che possono essere modificate cambiando le dimensioni delle sfere che costituiscono il cristallo bidimensionale. Verrà illustrato un metodo semplice e rapido per ottenere questi monostrati di particelle ordinate e per poterli depositare su vari substrati. Questi cristalli bidimensionali verranno utilizzati per depositare una matrice ordinata di nanoparticelle plasmoniche, con un ottimo controllo sulla loro forma e dimensioni, consentendo di realizzare particelle con proprietà su misura per l’applicazione desiderata. Verranno anche studiate applicazioni di queste nanoparticelle come sensori di molecole e per amplificare il segnale Raman grazie all’effetto SERS. Verrà inoltre studiato l’aumento di temperatura di queste nanoparticelle quando vengono illuminate da un laser risonante con la loro risonanza di plasma di superficie. Per applicazioni spettroscopiche applicate a sistemi biologici il cambiamento di temperatura può avere effetti rilevanti in un ambiente complesso come quello biologico. In seguito verrà dimostrato come questi cristalli colloidali bidimensionali possono essere utilizzati per creare altre classi di nanostrutture, come ad esempio una matrice di buchi nanometrici in un film metallico. Queste strutture sono studiate da quando è stato scoperta la loro capacità di far trasmettere attraverso strutture che sono molto minori del limite di diffrazione per le lunghezze d’onda trasmesse. Una sintesi che si basa sulle nanosfere autoassemblate può essere interessante per queste strutture grazie alla sua intrinseca flessibilità. Si possono infatti cambiare in modo molto semplice i parametri geometrici che caratterizzano la matrice di buchi quali le dimensioni dei buchi e il periodo degli stessi. Un’altra tipologia di nanostrutture che verrà realizzata sono film sottili nanostrutturati di TiO2. La titania è un semiconduttore di grande interesse tecnologico in molti campi diversi: dalla catalisi, alla conversione di energia ai sensori di gas. Verranno fabbricati, con la stessa tecnologia, dei film con una porosità ordinata e delle superfici nanostrutturate con un motivo a incavi. Infine verrà dimostrata la possibilità di utilizzare i cristalli colloidali 2D accoppiati con una tecnologia molto utilizzata dall’industria dei semiconduttori quale l’impiantatore ionico. Pattern nanometrici verranno realizzati su silicio utilizzando le nanoparticelle autoassemblate come maschera per il fascio ionico.
Matcheswala, Akil Mannan. "GOLD NANOSPHERES AND GOLD NANORODS AS LOCALIZED SURFACE PLASMON RESONANCE SENSORS". UKnowledge, 2010. http://uknowledge.uky.edu/gradschool_theses/60.
Texto completoKandulski, Witold. "Shadow nanosphere lithography". [S.l.] : [s.n.], 2007. http://deposit.ddb.de/cgi-bin/dokserv?idn=985533013.
Texto completoPaudel, Trilochan. "Nanosphere Lithography for Nano Optical Applications". Thesis, Boston College, 2011. http://hdl.handle.net/2345/3155.
Texto completoThesis advisor: Krzysztof Kempa
Many different techniques are available to create nanopatterns in nanoscale devices. However, a few are flexible and inexpensive enough to be practical in the nanotechnology. Here, we study the nanosphere lithography (NSL) based on a self-assembly of microspheres. Using this technique, we have developed various patterns in metallic films, ranging from honeycomb arrays of "quasi-triangles" to circular holes. These various patterns have been used subsequently either as nano-optical structures directly, with remarkable optical and plasmonic properties, or as substrates for further nano-processing. In one such nano-processing, the "quasi-triangle" patterns were used as a catalyst for carbon nanotube growth. The resulting aligned arrays of carbon nanotubes were employed in nanocoax solar cells. In another nano-processing, the arrays were used as masks for electrodeposition. In addition to the nano processing and measurements, we have employed the FDTD computer simulations, to develop a full understanding of the nano-optical and plasmonic properties of the developed structures
Thesis (PhD) — Boston College, 2011
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Physics
Gleason, Russell. "Nanosphere lithography applied to magnetic thin films". Thesis, California State University, Long Beach, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=1524199.
Texto completoMagnetic nanostructures have widespread applications in many areas of physics and engineering, and nanosphere lithography has recently emerged as promising tool for the fabrication of such nanostructures. The goal of this research is to explore the magnetic properties of a thin film of ferromagnetic material deposited onto a hexagonally close-packed monolayer array of polystyrene nanospheres, and how they differ from the magnetic properties of a typical flat thin film. The first portion of this research focuses on determining the optimum conditions for depositing a monolayer of nanospheres onto chemically pretreated silicon substrates (via drop-coating) and the subsequent characterization of the deposited nanosphere layer with scanning electron microscopy. Single layers of permalloy (Ni80Fe20) are then deposited on top of the nanosphere array via DC magnetron sputtering, resulting in a thin film array of magnetic nanocaps. The coercivities of the thin films are measured using a home-built magneto-optical Kerr effect (MOKE) system in longitudinal arrangement. MOKE measurements show that for a single layer of permalloy (Py), the coercivity of a thin film deposited onto an array of nanospheres increases compared to that of a flat thin film. In addition, the coercivity increases as the nanosphere size decreases for the same deposited layer. It is postulated that magnetic exchange decoupling between neighboring nanocaps suppresses the propagation of magnetic domain walls, and this pinning of the domain walls is thought to be the primary source of the increase in coercivity.
Murray, William Andrew. "Optical properties of nanoscale silver structures fabricated by nanosphere lithography". Thesis, University of Exeter, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.421567.
Texto completoДемиденко, Максим Геннадійович, Максим Геннадьевич Демиденко, Maksym Hennadiiovych Demydenko, Максим Миколайович Іващенко, Максим Николаевич Иващенко y Maksym Mykolaiovych Ivashchenko. "Сучасні технології отримання наноструктурованих поверхонь: micro/nanopatterning, nanoparticles, nanosphere lithography". Thesis, Видавництво СумДУ, 2008. http://essuir.sumdu.edu.ua/handle/123456789/4327.
Texto completoStoianov, Stefan Vladimirov. "Properties modification of nanopatterned surfaces functionalized with photo activated ligands". Diss., Virginia Tech, 2011. http://hdl.handle.net/10919/40434.
Texto completoPh. D.
Sirotkin, Evgeny. "Macroscopic Arrays of Ferromagnetic Nano-elements Produced by Etched Nanosphere Lithography". Thesis, University of Exeter, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.520489.
Texto completoPatoka, Piotr [Verfasser]. "Tunable plasmonic properties of nanostructures fabricated by shadow nanosphere lithography / Piotr Patoka". Berlin : Freie Universität Berlin, 2011. http://d-nb.info/102549024X/34.
Texto completoBrassat, Katharina [Verfasser]. "Surface nanopatterning by self-assembly techniques: Nanosphere- and block copolymer lithography / Katharina Brassat". Paderborn : Universitätsbibliothek, 2018. http://d-nb.info/1155467507/34.
Texto completoGibson, Kirsty. "Nanosphere lithography fabricated nanostructures for use in surface-enhanced Raman scattering biosensing applications". Thesis, University of Strathclyde, 2012. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=18940.
Texto completoAthanasiou, Modestos. "Fabrication and characterisation of III-nitride based nanostructure devices using nanosphere lithography techniques". Thesis, University of Sheffield, 2015. http://etheses.whiterose.ac.uk/8893/.
Texto completoLim, Jin-Hee. "Synthesis and Characterization of Nanostructures in Porous Anodic Aluminum Oxide Templates". ScholarWorks@UNO, 2011. http://scholarworks.uno.edu/td/455.
Texto completoChowdhury, Mustafa Habib. "The use of Surface Enhanced Raman Spectroscopy (SERS) for biomedical applications". Texas A&M University, 2005. http://hdl.handle.net/1969.1/4816.
Texto completoKent, Ronald Douglas. "Controlled Evaluation of Silver Nanoparticle Dissolution Using Atomic Force Microscopy". Thesis, Virginia Tech, 2011. http://hdl.handle.net/10919/35632.
Texto completoMaster of Science
Tiu, Brylee David Buada. "Conducting Polymers for Molecular Imprinting and Multi-component Patterning Applications". Case Western Reserve University School of Graduate Studies / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=case1449227860.
Texto completoLiu, Chang. "Controlled Evaluation of Silver Nanoparticle Dissolution: Surface Coating, Size and Temperature Effects". Diss., Virginia Tech, 2020. http://hdl.handle.net/10919/97509.
Texto completoDoctor of Philosophy
Nanomaterials, defined as materials with at least one characteristic dimension less than 100 nm, often have useful attributes that are distinct from the bulk material. The novel physical, chemical, and biological properties enable the promising applications in various manufacturing industry. Silver nanoparticles (AgNPs) represent one of the most widely manufactured nanomaterials and has been used as the antimicrobial agent in a wide range of consumer products. However, either the AgNPs themselves or dissolved Ag+ ions has a significant potential for the environmental release. The environmental fate and transport of AgNPs drawn considerable attentions because of the potential danger to environment and human health. Dissolution of nanoparticles is an important process that alters their properties and is a critical step in determining their safety. Ag+ ions migrate from the nanoparticle surface to the bulk solution when an AgNP dissolves. Studying nanoparticles' dissolution can help in the current move towards safer design and application of nanoparticles. This research aimed to acquire comprehensive kinetic data of AgNP dissolution to aid in the development of quantitative risk assessments of AgNP fate. AgNP arrays were produced on glass substrates using nanosphere lithography (NSL) and changes in the size and shape during the dissolution process were monitored by atomic force microscopy (AFM). First, surface coating effects were investigated by using three different coating agents. Coatings prevented dissolution to different extents due to the various way they were attached to the AgNP surface. Moreover, small, medium, and large sized AgNPs were used to study the size effects on AgNP dissolution. The surrounding medium concentration and temperature were the two variables that were included in the size effects study.
Kent, Ronald Douglas. "Controlled Evaluation of Metal-Based Nanomaterial Transformations". Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/74998.
Texto completoPh. D.
Aleeva, Yana. "Fabrication and characterisation of ZnO nanostructures: from nanoscale building blocks to hybrid nanomaterials - towards emerging technologies in sensing applications". Doctoral thesis, Università di Catania, 2012. http://hdl.handle.net/10761/977.
Texto completoNeupane, Suman. "Synthesis and Electron Emission Properties of Aligned Carbon Nanotube Arrays". FIU Digital Commons, 2014. http://digitalcommons.fiu.edu/etd/1168.
Texto completoVyas, V. "AN ATOMIC FORCE MICROSCOPY BASED INVESTIGATION OF INTERFACIAL PROPERTIES OF BIOCOMPATIBLE CLUSTER ASSEMBLED THIN FILMS". Doctoral thesis, Università degli Studi di Milano, 2011. http://hdl.handle.net/2434/155514.
Texto completoUshkov, Andrei. "Extraordinary optical transmission in holographic and polycrystalline diffractive nanostructures". Thesis, Lyon, 2020. http://www.theses.fr/2020LYSES026.
Texto completoThe thesis is devoted to the Extraordinary Optical Transmission observed in diffractive systems. An industrial need in integration and miniaturization of optical components stimulates the development of planar grating-based devices with thicknesses comparable to operating wavelengths. The EOT effect is perspective for plasmonic applications in structure-induced colors, optical filtering, lasing, optical biosensors due to the improved signal-to-noise ratio and a simplified device design. Aimed at practically available materials and industrially-compatible surface nanotexturing methods, a systematic study of EOT through continuous aluminum films was performed. A modification of laser interference lithography allowing rapid fabrication of variable depth gratings was proposed, theoretically established and experimentally validated. The variable depth defines the efficiency of plasmonic coupling at a fixed wavelength, offering additional possibilities for light manipulations. Using this approach the existence of optimal grating depth for EOT was demonstrated experimentally and depth-resolved structure-induced colors were observed in transmission. For the first time the effect of EOT was experimentally measured in polycrystalline samples, fabricated via nanosphere photolithography. A phenomenological model of EOT in polycrystaline structures and a dimensionless coefficient of disorder are proposed to explain measured transmission curves. The grating depth and disorder concurrence was studied numerically. The systematic study of EOT in various diffraction systems presented in this thesis might pave the way towards more effective plasmonic devices and industrial applications
Piccotti, Diego. "Two-Dimensional Nanostructure Arrays for Plasmonic Nanolasers". Doctoral thesis, Università degli studi di Padova, 2019. http://hdl.handle.net/11577/3423324.
Texto completoNell'ultima decina di anni, l'interesse per i nanolaser plasmonici è cresciuto siccome sono uno tra i modi più promettenti per la miniaturizzazione dei laser. Infatti, questi dispositivi possono superare il limite di confinamento fisico della luce, grazie alla cavità virtuale data dalle nanostrutture plasmoniche che sostituiscono la convenzionale cavità ottica macroscopica. Inoltre, questi dispositivi plasmonici possono supportare modalità di funzionamento ad alta velocità, bassa soglia di emissione laser e una direzionalità ben definita. Per questa ragione, durante questo progetto, ci siamo concentrati sulla progettazione, la sintesi e la caratterizzazione di nanolasers plasmonici basati su array di nanocupole di oro e array di nanodischi di argento. Al fine di sintetizzare reticoli di nanoparticelle con un ordine elevato, abbiamo utilizzato la Nanosphere Lithography (NSL), una tecnica economica e ad alta produttività basata sull'autoassemblaggio di nanosfere di polistirene. Grazie alla versatilità della NSL, abbiamo sviluppato diversi protocolli di nanofabbricazione, combinando la NSL con i processi di Reactive Ion Etching (RIE) e deposizione fisica da vapore (PVD). Successivamente, abbiamo studiato le proprietà ottiche dei campioni sintetizzati, ricostruendo la struttura a bande ottica lungo le direzioni di alta simmetria dello spazio reciproco. Abbiamo selezionato due adeguati emettitori coloranti, la Pyridine 2 e lo Styryl 9M, al fine di accoppiare la loro emissione con le modalità ottiche dei reticoli nanostrutturati, sulla base delle informazioni della struttura a bande ottica. Inoltre, per ottimizzare le proprietà plasmoniche e l'amplificazione del campo locale delle nanostrutture metalliche, delle simulazioni numeriche sono state effettuate tramite il software COMSOL Multiphysics. L'interazione tra il colorante e la struttura plasmonica ha generato un'emissione amplificata. In particolare, nel reticolo di nanocupole di oro accoppiato alla piridina 2 disciolta in etanolo, un'amplificazione dell'emissione si presenta a720nm con un comportamento a soglia a 0.9 mJ/cm^2 . Inoltre, è stata ottenuta un'emissione direzionale a 17° con una divergenza angolare di 3° che avviene lungo l'anomalia di Rayleigh. Confrontando i risultati dei reticoli di nanocupole di oro con quelli dei reticoli di nanocupole di silice, abbiamo concluso che i modi di reticolo danno un contributo alla direzionalità dell'emissione, mentre i modi plasmonici forniscono una riduzione della soglia laser superando così la perdita di energia. Il reticolo esagonale di nanodischi di argento mostra un comportamento simile a quello con le nanocupole di oro: abbiamo trovato una soglia laser a 1.6 mJ/cm^2 , con anche una simile FWHM. In questo caso, questo fascio è diretto a 65° e presenta una divergenza angolare di circa 14° . Inoltre, abbiamo studiato anche un nanolaser con un mezzo di guadagno a stato solido per l'interesse nelle applicazioni e nell'integrazione di dispositivi su chip. Il colorante laser Styryl 9M è incorporato in un film di PMMA e accoppiato con un reticolo di nanocupole di oro. Questo sistema a stato solido presenta un'emissione amplificata a 795 nm con una soglia di 1.2 mJ/cm^2 e una FWHM di circa 26 nm. Questo campione manifesta anche un'emissione direzionale a 24° con una divergenza angolare di 6° . Ulteriori ricerche hanno dimostrato la possibilità di eliminare il substrato, creando un dispositivo autoportante, che presenta un'emissione amplificata con proprietà simili a quella con il substrato. Infine, per discernere la natura spontanea o stimolata dell'emissione, abbiamo misurato la coerenza del raggio emesso. Tramite un interferometro di Michelson dedicato, la lunghezza di coerenza è stimata a circa 29 um per i reticoli di nanocupole d'oro sopra la soglia. Questo risultato ha dimostrato che è possibile ottenere un'emissione coerente, a bassa soglia e altamente direzionale, accoppiando un colorante fluorescente adeguato con una cavità virtuale opportunamente progettata e realizzata da una reticolo ordinato di nanostrutture plasmoniche.
Ludemann, Michael. "In situ Raman-Spektroskopie an Metallphthalocyaninen: Von ultradünnen Schichten zum organischen Feldeffekttransistor". Doctoral thesis, Universitätsbibliothek Chemnitz, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-206568.
Texto completoKandulski, Witold [Verfasser]. "Shadow nanosphere lithography / vorgelegt von Witold Kandulski". 2007. http://d-nb.info/985533013/34.
Texto completoWu, Wen-Hsien y 吳文獻. "Development of nanofabrication technique using Nanosphere Lithography". Thesis, 2006. http://ndltd.ncl.edu.tw/handle/15150840482140437255.
Texto completo國立成功大學
光電科學與工程研究所
94
Recently, Nanosphere lithography (NSL) has attracted a lot of interests because it is potentially a low-cost nanofabrication technique Nanostructure fabrications using NSL have been realized by various researchers. In this dissertation, nanofabrication using NSL has been studied and successfully demonstrated. The content of this dissertation is divided into two parts. First, two experimental methods (Drop Method and Capping Method) that lead to the formation of the NSL shadow mask are studied. This shadow mask is composed of a single layer of closed-packed two-dimensional array of nanometer-scaled silica spheres. The experimental conditions for both methods are optimized in order to fabricate a NSL shadow mask that covers a large area. It is observed that the Drop Method usually results in smaller mask area and is not suitable for further nanofabrication. In the other hands, the Capping Method can produce mask with large area and is further studied. The effects of the particle density and the type of solution using the Capping method are investigated. Both are important factors for NSL mask fabrication. Furthermore, a template-assisted NSL mask is also successfully demonstrated. In the second part of this dissertation, the NSL shadow mask is used as the shadow mask for metal depositions. Three types of metals (gold, silver, and aluminum) are selected for due to their visible-near IR localized surface plasmon resonance (LSPR) wavelength. Arrays of metal nano-clusters on top of the substrates are successfully fabricated and can be observed by optical microscope. Absorptions peaks from localized surface plasmon resonance from the metal clusters can be observed in the absorption measurements. The resonance wavelength is found to red-shift when the size of the metal clusters increases. In addition, it is also found that the resonance wavelength is very sensitive to the surrounding of the metal clusters. The resonance wavelength red-shifts when the metal clusters are covered by a thin-film of Silicon oxide. In conclusion, nanofabrication using Nanosphere lithography is successfully demonstrated. It provides a simple and low-cost way to fabricate nanostructures on a flat surface and has huge potential for industrial and research applications.
Chou, Fang-yu y 周芳瑜. "Fabrication of Metallic Nanostructure using nanosphere Lithography". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/47715335189688714940.
Texto completo國立成功大學
光電科學與工程研究所
95
Fabrications of metallic nanostructures are becoming increasingly important in a variety of scientific applications. In this dissertation, metallic nanoparticle arrays are fabricated using nanosphere lithography. A single layer of nanosphere arrays consisted of nanospheres with diameters of 0.5µm, 0.7µm, 1.0µm, 1.6µm, 2.0µm is utilized as the shadow mask for the metallic nanoparticles arrays. The optimized experimental conditions for the formation of nanosphere arrays are systematically studied. The maximum area of this single layer nsnosphere array can be obtained is approximately 30mm x15 mm limited by the current experimental instruments. It is also able to form a single layer of nanosphere arrays within a pre-patterned 60 �慆-wide trench. O2 plasma etching is also able to reduce the size of polystyrene nanospheres. The absorption spectra from Ag nanostructures fabricated with nanopshere lithography exhibit responses from localized surface plasmon resonant scattering (SPRS) from the Ag nanostructures. The observed localized surface plasmon resonance blue-shifted as the size of metallic nanoparticle decreased. The resonance also blue shifted as the shape of metallic nanoparticle changed from a triangular form to a circular form. The application of Ag nanostructures in organic solar cell is also investigated. The power conversion efficiencies of the solar cell with Ag nanoparticles (2.42%) are higher than the device with Ti nanoparticles (1.68%). Effect from the surface plasmon resonance scattering is a possible cause for this enhanced power conversion efficiency.
Lin, Fang-Yi y 林芳宜. "Gallium Nitride Nanowires Growth using Nanosphere Lithography". Thesis, 2018. http://ndltd.ncl.edu.tw/handle/df3m6e.
Texto completo國立交通大學
電子物理系所
106
The benefits for nanowire device applications are based on quantum confinement effect and larger surface. The important requirement of that is the precise control of GaN nanowires with well uniformity. In addition, investigating the key factor to determine the growth orientations of nanowires is important for nanowire devices To reduce substrate cost and integrate with silicon, the bottom-up method via HVPE is used to grow GaN nanowires with Au/Ni catalysts on the low-cost Si(111). However, the average diameter and growth locations of nanowires are nonuniform due to the Au/Ni droplets with random sizes and locations before nanowires growing. The Au/Ni catalysts-assisted method is based on the VLS or VSS growth mechanism. According to both growth mechanisms, the average diameter of the nanowires are almost the same size as the tip of the catalyst, so nanosphere lithography (NSL), an effective method, is introduced to improve the uniformity. The NSL improvement is achieved by controlling the large-area catalyst positions and sizes to define where the nanowires grow and make the diameters of nanowires more consistent. The main growth orientation of the GaN nanowires grown via Au/Ni catalysts on four different substrates or grown via different catalysts on Si (111) is m-plane, so there is no direct relation between the growth orientation and the lattice structure of substrate or different catalysts under our growth conditions. In summary, the growth orientation is almost consistent, so the VLS growth mechanism is dominant. The key factor to determine the growth orientation of GaN nanowires is that at the initial nucleation phase, the composition of Ga-part in the liquid droplet is low, which leads to the non-polar m-axis GaN nanowire growth.
Tsai, Shou-Hsuan y 蔡守軒. "Fabrication of Nanostructure with Template-Assisted Nanosphere Lithography". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/62011593028849957507.
Texto completo國立成功大學
光電科學與工程研究所
96
In this thesis, the improvement of nanosphere lithography (NSL) and the template-assisted nanosphere lithography were both reported. Nanosphere lithography utilizes one single layer of close-packed nanosphere arrays as a shadow mask to fabricate periodic nanostructure on top of different substrates and has been developed in our group for several years. Large area (30 mm × 15 mm) consists of one single layer of nanosphere arrays can be fabricated. However, we have difficulties to deposit metal through this single layer of nanosphere arrays. In this research, the residue of surfactant located between spheres was identified to be the origin of this problem with the help from scanning electron microscopy. By annealing in high temperature or treating with oxygen plasma, the residue can be effectively removed and large area (20μm × 20μm ) of metallic nanoparticles arrays can be fabricated. Template-assisted nanosphere lithography was also developed in this research. Nanosphere arrays were fabricated inside the photolithography-fabricated patterns. The effects of various parameters were studied and optimized to fabricate a single layer of nanosphere arrays. The arrays were subsequently treated with reactive ion etching (RIE) to slightly reduced the size of the sphere. After depositing metal through the remaining nanosphere arrays, large area of periodic nano-hole arrays can be fabricated. However, the limitation of the RIE using a metallic hard mask has delayed further developments of the template-assisted nanosphere lithography. Therefore, modification of the process is required to avoid the metallic hard mask. We believe that template-assisted nanosphere lithography can be applied in several important optoelectronic devices and advanced their device performance.
Meng-HungTsai y 蔡孟宏. "Patterning of TCO Film Using Nanosphere Lithography Technique". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/96562502932960815521.
Texto completoHo, Yu-Hsiu y 何瑜修. "A Study of Antireflective Structure Using Nanosphere Lithography". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/80973993856405834293.
Texto completo國立交通大學
材料科學與工程學系
100
When the light impinges the interface between two different media, some of light is reflected at interface. The reflection creates many problems, such as flare and glare, and may reduce the performance of electro-optical devices. Traditionally, a coating of dielectric thin film with low refractive index was used to reduce the reflection. But the coating can only suppress the reflection in a single or narrow-band wavelength. However, the reflection can be reduced in broadband, if the surface has nanoscale protuberance arrays. In this study, we developed a process to fabricate the protuberance arrays on quartz surface using nanosphere lithography and two different polystyrene (PS) sphere sizes, 600 nm and 200 nm. First, the polystyrene sphere arrays can be prepared on the quartz surface by a self-assembly technique. The protuberance arrays on quartz surface were then fabricated by CF4 reactive ion plasma etching under the masking of polystyrene sphere. Different profiles of protuberances such as spot-like, truncated-cone, and paraboloid-like shapes can be made and controlled by etching time. At fixed CF4 flow rate and pressure, the aspect ratio of paraboloid-like protuberance arrays of 200 nm in period is about 1.35 and 1.15 for 600 nm PS sphere arrays as a mask. In addition, the quartz surface with paraboloid-like profile arrays is found to show better transmittance than other structures. Simulations were also carried out to assess if the paraboloid-like profile arrays on the quartz surface have the potential to enhance the light power in OLED. The light power of OLED as a function of different period and height in the paraboloid nanostructure was calculated using FullWAVETM, a finite-difference time-domain (FDTD) simulator. When the period of protuberance is 200 nm and the aspect ratio of protuberance is 3, the light power of OLED substrate with paraboloid-like protuberance arrays shows 14% increase.
Chung-BinTseng y 曾重賓. "Development of Plasma-Assisted Nanosphere Lithography and its Application". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/19964941008396383275.
Texto completo國立成功大學
光電科學與工程研究所
98
In this dissertation, various nanofabrication techniques using nanometer-sized colloids are developed and different types of nanoparticle arrays are successfully fabricated. Large areas (~ 3 mm x 3 mm) of ordered periodic arrays are obtained by all methods investigated. First, metal nanoparticles arrays were fabricated using conventional Nanosphere Lithography (NSL). Localized surface plasmon resonances (LSPR) of these nanoparticles made from different metal were investigated. LSPR experiences red-shift as the physical sizes increase or higher-refractive-index substrate was used. Second, NSL combining with oxygen plasma treatments was demonstrated to be able to fabricate metallic nanotriangles with different side length. LSPR also red shifts as the size of the nanotriangles increases due to oxygen plasma etching. Oxygen plasma etching also reduced the gap distance between nanotriangles. The smallest gap distance fabricated was estimated to be 40 nm. Nanotriangles pairs with sub-100nm gap are referred as bowtie nanoantennas that are of great importance in Nanophotonics. LSPR of the nanoantenna was observed to red-shifted as the gap distance decreased. In addition, preheated nanosphere solution was used along with the plasma-treated NSL. This method can fabricate bowtie nanoantenna with very narrow and uniform gap separation that regular plasma-treated NSL can not obtain. Third, two-dimensional circular nanodisk arrays were also fabricated by using Nanospherical Lens Lithography (NLL). Nanodisks with diameters between 800 to 960 nm were fabricated using 1 μm polystyrene nanospheres as the lithographic mask. 500 nm polystyrene nanospheres were also demonstrated to obtain similar results. Plasmonic properties of Metal-Insulator-Metal nanodisks using NLL were investigated. LSPR mode splitting was observed in the transmission spectra for nanodisk arrays with different disk diameters. In conclusion, nanofabrication techniques using Nanosphere Lithography, Plasma-treated NSL, Plasma-treated NSL using pre-heated nanospheres, and Nanospherical Lens Lithography were developed in this research. Each of the techniques can fabricated large-area ordered nanoparticles arrays with low fabrication cost. The future applications for these fabricated arrays can contribute greatly in Nanophotonics and offer exciting experimental results.
Huang, Wan-Ru y 黃琬茹. "Fabrication of Ni-silicide / Si heterostructure nanowires by nanosphere lithography". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/79656754305490325260.
Texto completo國立中興大學
材料科學與工程學系所
99
With the shrinking of the dimensions of electronic devices, the-low resistivity and high-stability metal silicides have been widely used as the contacts on source, drain, gate in transistors to reduce contact resistance. Preferred silicides for the applications are titanium silicide (TiSi2), cobalt silicide (CoSi2) and nickel silicide (NiSi). Because NiSi has a wide process window, less silicon consumption, low film stress, nickel silicide is consider to be the most promising candidate for scaled devices below one hundred nanometers. In the study of nanoelectronic devices, carbon nanotubes (CNT) and silicon nanowires (SiNW) have been used as building blocks. However, the structure and size of CNTs is difficult to control process. The size of SiNWs can be controlled by a lithography technology, and can be integrated with semiconductor process. Therefore, SiNW has advantage over CNT. As the semiconductor industry continues to shrink the dimensions of electronic devices, the study of properties of metal silicide nanowires becoming more and more importance. In this study, a large number of nanowires with a controlled diameter, growth orientation were fabricated by combining polystyrene nanosphere lithography with metal-induced catalyst etching. Then, nickel silicide/ silicon heterostructure nanowires were formed by glancing angle deposition technique and solid-phase reaction. The effects of the size of Si nanowires on the formation of nickel silicide and the electrical property of nickel silicide/silicon interfaces in heterostructure nanowires were investigated. The results show that nickel silicide/silicon heterostructure nanowires were fabricated successfully. The front-end of nickel silicide part is Ni3Si2, The silicides formed at the silicide/silicon interface were NiSi and NiSi2 in the thinner nanowires (diameter≦105nm) and the thicker nanowires (diameter≧110nm), respectively, which is because that the formation of nickel silicide was a surface diffusion controlled process. The interfacial electrical properties of NiSi/silicon hetrojunction (in the thinner nanowires) and NiSi2/silicon hetrojunction (in the thicker nanowires) were Schottky contact and Ohmic contact, respectively.
Wang, Chien-hsun y 王建勳. "Periodic arrays 2D well-ordered nanostructures fabricated via nanosphere lithography". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/31538189638263127424.
Texto completo國立中央大學
化學工程與材料工程研究所
96
In the present study, we have demonstrated that 2D periodic arrays of nickel metal and silicide nanodots can be successfully fabricated on (111)Si substrates by using the polystyrene (PS) nanosphere lithography (NSL) technique and thermal annealing. The results of an investigation on the interfacial reactions between the Ni nanodots and (111)Si substrates after different heat treatments are reported. From the TEM and SAED analysis, only epitaxial NiSi2 nanodots were found to form on (111)Si at a temperature as low as 300 °C. The results indicated that the growth of epitaxial NiSi2 is more favorable for the samples with smaller Ni nanodot sizes. The epitaxial NiSi2 nanodots were found to grow with an epitaxial orientation with respect to the (111)Si substrates: [111]NiSi2//[111]Si and {220}NiSi2//{220}Si. In addition, these epitaxial NiSi2 nanodots formed on (111)Si were observed to be heavily faceted and the faceted edges of the NiSi2 nanodot were identified to be parallel to <1 0>Si directions. On the other hand, during the experiments, the double-layered arrays of PS spheres were occasionally found to form on silicon substrates. The epitaxial NiSi2 nanodot arrays formed from the bilayer masks exhibit larger interparticle spacings and smaller particle sizes. By combining the nanosphere lithography, heat treatments, wet chemical etching and electrodeposition techniques, we also successfully fabricate large-area shape- and size-tunable metal nanostructures (nanobowls and nanopillars) and nanohole arrays on Si and SiGe substrates. The morphology evolution, size uniformity and crystal structure of the produced nanostructures have been systematically investigated by SEM, AFM, TEM, and SAED analyses. The observed results present the exciting prospect that with appropriate controls, the colloidal NSL technique promises to offer an effective and economical patterning method for fabrication of a variety of well-ordered nanostructures with selected shape, size, and periodicity on different substrates without complex lithography.
Chen, Yi-Jung y 陳沂蓉. "Construction of Two dimensional Au sphere array using Nanosphere lithography". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/35016953960254885745.
Texto completoWu, Hung-Chun y 吳泓均. "Fabrication of Nanostructure by Nanosphere Lithography Technology and Its Applications". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/48332193534762899682.
Texto completo中華大學
工程科學博士學位學程
101
Periodic nanostructures have recently gained widespread attention because of their unique properties and promising applications in numerous fields, such as sensors, photonic crystals, and optoelectronic devices. Various techniques can be used to fabricate periodic arrays of nanostructures, including X-ray lithography method, electron-beam lithography (EBL), and interference lithography (IL). Although these lithographic techniques have been used to control the morphology of the periodic structure arrays, they are time consuming and costly. Hence, researchers have focused on the study of simple, high-resolution and low-cost nanosphere lithography (NSL) technique to fabricate periodic nanostructure arrays. This dissertation investigates the structure, morphology, wettability, and optical properties of Cr, CrN, and polycarbonate (PC) nanostructure patterns using technology based on NSL. The content of this dissertation is divided into three sections. Firstly, this study shows the effect on their capillary force and convective flux properties associated with controlling the spin speed of the spin coater and concentration of the polystyrene (PS) nanosphere solution. A monolayer of nanospheres with a hexagonal close-packed array structure was formed on glass substrates using the spin-coating method. The size and shape of the size-tunable ordered PS nanosphere arrays structure can be manipulated using the reactive ion etching (RIE) process. The second section of this dissertation investigates the fabrication of hierarchical porous Cr nanoring array patterns using a magnetron sputtering process and NSL-based technique. To study the optical effects of the substrate and the Cr ring-shaped nanostructure film, different nanosphere sizes and deposition thicknesses are introduced to adjust the size and shape of the ring-shaped nanostructures. The optical transmittance of porous Cr nanoring arrays can be enhanced using surface plasmon resonance. The luminous enhancement at a special wavelength of 525 nm and better color purity were observed in this Cr nanoring structure. This new approach has various potential applications in optoelectronic devices and optical sensors. The third section of this dissertation shows that the surface of the nanomold of CrN nanohole arrays has a low surface energy. The optical properties of the antireflective PC-tapered nanopillar layer were successfully replicated from the CrN nanomold. These antireflective surfaces are promising for the fabrication of antireflective surface structures with various bands, and these antireflective optical materials have wide applications in various optoelectronic products.
Chen, Yen-Chang y 陳彥璋. "Low-Cost Nanofabrication of Semiconductor Optoelectronic Devices using Nanosphere Lithography". Thesis, 2016. http://ndltd.ncl.edu.tw/handle/69243899402239130690.
Texto completo國立臺灣大學
光電工程學研究所
104
In this dissertation, we will demonstrate the fabrication of various nanoscale optoelectronic devices using a low-cost nanofabrication method developed from Nanosphere Lithography (NSL). First, we will discuss how to use a top-down nanofabrication approach to fabricate silicon nanonet field-effect transistors (FETs). We will also discuss the electric properties of these FETs and apply them for biosensing application. In the final part of this these, I will discuss how to use the two-step etch technique and regular photolithography to fabrication InGaN/GaN cavity LED. The basic electric and optical properties will also be discussed.
Li, Yu-Hsien y 李宥賢. "The Study of Magnetic Nano Dots Array by Nanosphere Lithography". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/15099116132888799125.
Texto completo中興大學
材料工程學系所
95
Patterned media can reduce the intergranular interaction between the magnetic grain particles. This feature can reduce the noise signal generation in hard disk and if incorporate with high Ku value material can also slacken the superparamagnetism effect to occur and hence obtain a higher recording density. Nanosphere lithography has advantages such as low-cost, high-throughput and can efficiently producing large scale well-ordered 2D periodical arrays in nano-structures. This study using the self- assembly capability of nanosphere to producing high Hc alloy type Sm-Co, Fe-Pt nano dots array and soft magnetic material Co dots. The outcome was then used to analysis the relationship between magnetic nano-particle domain wall structure transformation and intergranular interaction. From the experiment result, it shows that using 508nm nanosphere mask can obtain 178nm Fe-Pt nano dots array. Without external field exertion, the dots array is usually multi-domain structure and with annealing treatment at temperature 600℃, the Hc value can rise to 4.42kOe. The experiment results showed that covering the Fe-Pt dots array with 10nm cobalt thin film can significant increasing the Hc value of the cobalt film which is single domain structure with the same dipole rotation direction.
Zheng, Ming-Zhe y 鄭名哲. "Fabrication of Metal Mesh Transparent Conductive Films Using Nanosphere Lithography". Thesis, 2018. http://ndltd.ncl.edu.tw/handle/b4r658.
Texto completo國立中興大學
材料科學與工程學系所
106
Metal mesh has high light transmission, high conductivity and high flexibility, so it is considered to be used to replace the indium tin oxide(ITO)which is commonly used for transparent conductive electrode. We use nanosphere lithography to prepare silver metal mesh.the advantages of nanosphere lithography are low cost and convenient. Since silver is easily oxidized to silver oxide, indium-zinc-oxide (ITZO) is deposited to protect silver. ITZO has good photoelectric properties in the normal temperature process, and it can also improve the overall light transmission. We have successfully prepared single layer closed-packed structure of 800nm and 2000nm polystyrene spheres.Metal mesh was obtained by oxygen plasma etching the nanosphere template、sputtering and nanosphere lift-off. It can be known from the experiment that as the thickness of silver increases, the light transmission decreases, and the light reflection increases.In the infrared light region,we also observe the extraordinary optical transmission.This phenomenon is related to the resonance coupling of the surface plasma and the electromagnetic wave. The meshes prepared by using 800nm and 2000nm polystyrene as templates have the highest figure of merit in Ag 20nm/ITZO 40nm and Ag 30nm/ITZO 40nm respectively, and their values are 3.1mΩ-1 and 1.1mΩ-1. It can be known from the experiment that during the sputtering process, the atoms will scatter into the bottom of the nanosphere.It causes the line width of mesh to increase and the light transmission to decrease, thereby degrading the figure of merit. The mesh prepared by using 2000 nm polystyrene as a template has high light transmission,but since the line width of mesh is partially discontinuous,the resistance value is increased, and the figure of merit is decreased.
Yen, Chen-Chung y 閻正中. "Applications of Nanoscale Optoelectronic Devices Fabricated Using Low-cost Nanosphere Lithography". Thesis, 2017. http://ndltd.ncl.edu.tw/handle/6zg9xp.
Texto completo國立臺灣大學
應用物理研究所
105
In this study, we will demonstrate several nanoscale optoelectronic devices fabricated using Nanosphere Lithography (NSL). First, periodic nanoparticles and inverted pyramid nanostructures are fabricated on top of flexible substrates using template-stripping method. Optical properties of these nanostructures are investigated experimentally and verified theoretically by using finite-difference time domain (FDTD) methods. Second, optical properties of periodic aluminum nanodisks are also investigated and the simulated extinction spectra reveal a tunable lattice plasmon mode peak within the visible spectra range. We will cover the fabricated nanodisks arrays with gain materials to study the lattice plasmon assisted lasing. In the last part of this dissertation, we will demonstrate the fabrication of silicon nanonet field-effect transistors (FETs). The electric properties of these nanonet FETs are investigated. We will also discuss the results measured by these Si nanonet FETs for chemical and biosensing applications.
Hsieh, Ho-Yen y 謝合彥. "Fabrication of Nanostructure Array by Reactive Ion Etching and Nanosphere Lithography". Thesis, 2009. http://ndltd.ncl.edu.tw/handle/64818896336121462436.
Texto completo潘羿明. "Analysis of GaN Grown On Patterned Sapphire Fabricated by Nanosphere Lithography". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/35073935886019317327.
Texto completo國立清華大學
光電工程研究所
101
GaN material has a great development space for blue LED. However, lattice mismatch exists between GaN and substrate material, so it is restricted to be used. Recently, GaN-based LED grown on a patterned sapphire substrate (PSS) is widely studied. It can not only efficiently reduce threading dislocation (TD) density of GaN grown on, but also enhance light extraction efficiency as well. We successfully fabricate PSS of different scales by nanosphere lithography and compare the characteristics of GaN on each substrate. We compared the quality of GaN films grown on them by PL and XRD. The results indicate that the quality is the best when grown on pattered sapphire substrates with period 100 nm and duty ratio 100%. The results match. We can conclude that the quality of GaN films is better when grown on PSS with smaller period and larger duty ratio.
Chen, Ping-Chi y 陳品齊. "Fabrication of Superhydrophobic Polymer Surface Using Nanosphere Lithography and Plasma Modification". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/94996001246427744658.
Texto completo中原大學
化學工程研究所
101
In this study, polystyrene and PET polymers covered with silica nanospheres in the form of monolayer were modified by CF4 plasma to form nanostructured surface. The plasma diagnostics (OES) and surface analysis (CA, FE-SEM, XPS, UV-vis) were used to elucidate the process-structure-property relationship. The results revealed that super-hydrophobic surface with water contact angle of 155° were achieved on polystyrene polymers. The surface consisted of nano-pillars of about 300 nm in height and 100 nm in diameter, and the fluorine-to-carbon atomic ratio was about 0.8. The surface was also oleophobic as the CH2I2 contact angle reached 110°. Moreover, the surface exhibited good self-cleaning effect and visible light transmittance. Due to its high oxygen content in the pristine PET polymer, the CF4 plasma modified PET surface was not super-hydrophobic. Although nano-pillars were formed on PET surface, but its fluorine-to-carbon ratio was lower and oxygen-to-carbon ratio was higher than the plasma modified polystyrene. Therefore, a thin layer of fluorocarbon film of about 30 nm was deposited on CF4 plasma modified PET surface. Consequently, the surface hydrophobicity (~169°) and fluorine-to-carbon ratio (1) was increased dramatically and oxygen-to-carbon ratio was significantly decreased. The modified PET surface exhibited excellent self-cleaning effect since the WCA hysteresis was about 5° and the sliding angle was less than 8° in dynamic contact angle analysis.
Yu-MinHuang y 黃鈺閔. "Combination of Nanosphere and Electron-beam lithography to fabricate large-scale nanostructures". Thesis, 2015. http://ndltd.ncl.edu.tw/handle/32575645711046690534.
Texto completoLi, Chan-chin y 李展進. "Surface enhanced Raman active substrate fabricated by nanosphere lithographic technique". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/30350893344714137086.
Texto completo國立中央大學
光電科學與工程學系
102
Surface enhanced Raman scattering (SERS) active silver periodic particle array (PPA) substrates are fabricated by nanosphere lithographic technique. Base on the reported results in literatures, the shift of plasmon resonance wavelength can be manipulated via varying the fabrication parameters such as particle size, thickness and shape. Experimentally, thermally induced shape change was observed which results in the red shift of the resonant wavelength. The result is in close agreement with that obtained by Van Duyne. In addition, a local site on the PPA with resonance wavelength close to =532 nm was chosen to examine the resonant Raman response from model molecule Rhodamine 6G (R6G). The measured Raman spectrum, clearly reveals the vibrational fingerprint of the R6G molecule, demonstrating the enhancement capability of the fabricated substrate for molecular analysis substrate. Finally, fluorescence life time measurement of R6G on various substrates was conducted by TCSPC system, with the aim to justify the interplay between substrate quenching effect and the enhancement factor of R6G.
"Development of Nanosphere Lithography Technique with Enhanced Lithographical Accuracy on Periodic Si Nanostructure for Thin Si Solar Cell Application". Doctoral diss., 2015. http://hdl.handle.net/2286/R.I.29713.
Texto completoDissertation/Thesis
Doctoral Dissertation Materials Science and Engineering 2015
Ji, Li active 21st century. "SiOx-based resistive switching memory integrated in nanopillar structure fabricated by nanosphere lithography". Thesis, 2014. http://hdl.handle.net/2152/26200.
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Wu, Kun-Yang y 吳坤陽. "Application of Interface Engineering and Nanosphere Lithography in the Organic Electronic Devices Fabrication". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/30001412451560990107.
Texto completo國立清華大學
材料科學工程學系
100
The energy level alignment between a metal and an organic semiconductor (M/O) is regarded as the dominant factor affecting carrier injection efficiency. In particular, it plays a crucial role in the performances of organic light emitting diodes (OLEDs) including electroluminance efficiency and life-time. Through electrode surface modification, the size and direction of the interface dipole can be introduced to modulate the energy alignment at the interface. In this study, a series of thiol compounds, including fluorine-substituted benzyl mercaptans, n-alkanethiol, cyano-terminated (CN-), trifluoro-terminated (CF3-), perfluroinated substituents and binary mixtures with opposite dipoles, were used to modify the silver anode through the formation of well-ordered self-assembled monolayers (SAMs) and applied in the fabrication of top-emitting electroluminescent devices. The device performances were measured and analyzed to understand the effect of modification on the charge injection. It is demonstrated that the same substituent placed at different positions on a phenyl ring results in different dipole moment and modulate the work function/charge injection differently. Furthermore we demonstrated that besides the dipolar functional group, the chain length of alkanethiol can be used to tune the tunneling distance for charge injection. Through selection of the two parameters (dipolar functional group and tunneling distance), the energy alignment can be fine-tuned and influence the charge balance and luminescence efficiency. VII Furthermore, SAMs of binary mixtures of n-decanethiol and the perfluorinated analogue were formed on silver surface. Through change of mixing ratio, the work function of silver can be tuned continuously over a wide range: from 4.1 eV to 5.8 eV. The mixed SAM-modified Ag surfaces were used as the anode in the fabrication of hole-only devices and electroluminescent devices using different hole-transporting materials (HTL). Through the analysis of charge injection efficiency/luminescence efficiency, strategy of improving hole/electron carrier balance is proposed. With generally low mobility associated with organic semiconductors and limitations on the fabrication involving lateral transistors as driving component, we also extended our work on vertical type transistors, which uses greatly reduced channel length to lower driving voltage and increase current output. A large-area and periodically patterned nanoporous Al grids with controlled pore size were fabricated by poly(ethylene oxide)-assisted self-assembly of polystyrene nanospheres. This grid layer was used as the base electrode in a space-charge limited transistor (SCLT) with vertical architecture. A high performance device with poly(3-hexylthiophene) (P3HT) as conducting semiconductor was achieved with a high on-current
Huang, Chao-Kai y 黃昭凱. "Applying Nanoparticles and Nanosphere-Lithography to Enhance Light Harvesting of Silicon Solar Cell". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/11594077584109837024.
Texto completo國立交通大學
應用化學系碩博士班
100
This thesis is focus on the anti-reflection and luminescent down-shifting property of silicon solar cell. The content is divided into three parts:(1) Nanoparticles_Silica (2) Nano-Honeycomb Structure Layer (3) Nano-Phosphors_YVO4:Bi3+:Eu3+. Part one: In this study, silica nanospheres dispersed in a surfactant solution were spin-coated on commercially available silicon solar cells to form colloidal crystals on the surface. This self-assembled nanoparticle layer served as an anti-reflection (AR) layer for solar cell devices. The self-assembled layer exhibits excellent anti-reflection properties in the UV and NIR wavelength regions. We also showed that the overall conversion efficiency of polycrystalline Si solar cells coated with the silica nanospheres was increased from 11% to 12.3% when using optimized spin-coating parameters and nanoparticle concentrations. Part two: This experiment demonstrates the process for manufacturing a ZnO honeycomb sub-wavelength structure using nanosphere lithography technology exhibiting excellent anti-reflection properties from the UV to NIR wavelength regions. This honeycomb nanostructure, combined with commercially available crystalline Si solar cells, show substantially improved conversion efficiency from 15.6% to 16.6% using optimized honeycomb sizes and precursor concentrations of ZnO. The present work develops an unsophisticated and economical technique suitable for industrial applications in producing a uniform and low-reflective texture. Part three: The colloids of YVO4 nanoparticles on micro-textured Si surface are demonstrated to have promising potential for efficient solar spectrum utilization in crystalline Si solar cells. The solar cells showed an enhancement of 4% in short-circuit current density and approximately 0.7% in power conversion efficiency when coated with YVO4 nanoparticles. The properties of cells integrated with YVO4 nanoparticles were characterized to identify the role of YVO4 in improved light harvesting. The current experiments conclude that the colloids of YVO4 nanoparticles not only act as luminescent down-shifting centers in the ultraviolet region but also serve as an anti-reflection coating for enhancing the light absorption in the measured spectral regime.