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Optical manipulation using planar/patterned metallo-dielectric multilayer structures : a thesis presented for the degree of Doctor of Philosophy in Electrical and Electronic Engineering at the University of Canterbury, Christchurch, New Zealand /Lin, Ling, January 1900 (has links)
Thesis (Ph. D.)--University of Canterbury, 2008. / Typescript (photocopy). "January, 2008." Includes bibliographical references (p. 179-206). Also available via the World Wide Web.
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Coherent plasmon coupling in spherical metallodielectric multilayer nanoresonators /Rohde, Charles Alan, January 2008 (has links)
Thesis (Ph. D.)--University of Oregon, 2008. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 156-162). Also available online in Scholars' Bank; and in ProQuest, free to University of Oregon users.
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Fundamental studies of the interaction between femtosecond laser and patterned monolayer plasmonic nanostructuresHuang, Wenyu. January 2007 (has links)
Thesis (Ph. D.)--Chemistry and Biochemistry, Georgia Institute of Technology, 2008. / Committee Chair: El-Sayed, Mostafa A.; Committee Member: Perry, Joseph W.; Committee Member: Srinivasarao, Mohan; Committee Member: Whetten, Robert L.; Committee Member: Zhang, Z. John.
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Plasmonic field effects on the spectroscopic and photobiological function of the photosynthetic system of bacteriorhodopsinBiesso, Arianna. January 2009 (has links)
Thesis (M. S.)--Chemistry and Biochemistry, Georgia Institute of Technology, 2009. / Committee Chair: Mostafa A. El-Sayed; Committee Member: Adegboyega K. Oyelere; Committee Member: Bridgette Barry; Committee Member: Joseph W. Perry; Committee Member: Mark R. Prausnitz.
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Investigation of optical properties of one-dimensional nanostructures with engineerable heliciity and surface modificationBai, Fan 23 June 2017 (has links)
In this work, the optical properties of two kinds of one-dimensional (1D) nanomaterials, mesoporous silicon nanowires (mpSiNWs) and plasmonic nanospirals (NSs), were studied. These emerging nanomaterials are of great interest because of their fundamental structure-derived properties and potential practical applications. Four aspects of these materials were analyzed in this work. First, although the fabrication mechanism of mpSiNWs has been studied previously via metal-assisted chemical etching, the porosification-induced disturbance to the etching direction, which plays a vital role in controlling the surface crystallinity of mpSiNWs, has not been characterized. In Chapter 2, I discuss the porosification etching mechanism of n-Si(111), which proceeds along the intrinsic back bond etching direction of [111] at room temperature. The porosification substantially weakens the back bonds under the sinking particles, resulting in the deviation of etching from [111]. The preferred direction of etching changes to that with a small angle α, because the direction-switching barrier increases with α and intrinsic back-bond etching is thermodynamically preferential. Second, mpSiNWs typically generate red photoluminescence (PL), but the PL mechanism is still under debate. A laser was used to oxidize the surfaces of mpSiNWs and tune the PL from red to greenish-blue (GB), as described in Chapter 3. The laser oxidation was tuned as a function of laser power, and a complex model of the laser-induced surface modification was proposed to account for the laser-power and post-annealing effect. The laser-induced modification of the PL of mpSiNWs may be useful for data encryption. Third, the fabrication of plasmonic NSs and the study of their optical activities are in their infancy. In Chapter 4, I describe the use of glancing-angle deposition (GLAD) to fabricate silver NSs (AgNSs) with controllable helicity and demonstrate that AgNSs have intrinsic optical responses that originate from their structural helicity. The optical activity of an AgNSs dispersion was characterized by circular dichroism (CD), and systematic engineering of the helicity revealed that their UV and visible optical activities have two different origins. Fourth, physical limits prohibit the sensitive differentiation of enantiomers. In Chapter 5, I describe the grafting of chiral molecules onto AgNSs, which dramatically enhanced the differentiation of L- and D-glutathione (GSH). AgNSs have very strong optical activities that are weakened by GSH adsorption. The severity of the chiroptical weakening effect varies with the absolute configuration of GSH, resulting in enantiomeric differentiation with an anisotropic g-factor of approximately 0.5. This chiral nanoplasmon-induced anisotropy g-factor is superior by 2 to 4 orders of magnitude to those obtained with other methods and about one-fourth of the theoretical value. This proposed method can be adapted to differentiate chiral drugs, which is highly desirable in the pharmaceutical industry for the production of single-enantiomer drugs.
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Enhancement of photo-conversion efficiency of organic solar cells by plasmon resonance effectOtieno, Francis Otieno January 2016 (has links)
A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of requirements for the degree of Master of Science. Johannesburg, 2015. / Organic Photovoltaic (OPVs) is a promising alternative technology to provide clean and inexhaustible energy due to their excellent optoelectronic properties of the active polymer blends. The organic polymers have low weight, tunable electrical and optical properties besides being relatively insensitive to film imperfections which in the long run enable low-cost high-throughput roll-to-roll processing. However, their photo-conversion efficiency (PCE) and instability to air remains their greatest drawback as these preclude their commercialization. Indeed the highest power-conversion efficiency reported in literature is between 10-12 % compared to their inorganic counterparts (40 %). Therefore there is great need for improvement to make them competitive with grid parity. In this thesis, the major factors limiting the efficiency of organic solar cells such as light absorption, exciton diffusion and dissociation as well as charge collection are investigated and discussed.
Despite the high thickness dependent absorption coefficients (>105 cm-1) within the visible spectrum the materials exhibit short exciton diffusion lengths (10-20 nm) which limit the optimal active layer thickness to a few nanometers. Improving optical absorption within this thickness forms the basis of this project. We report the use of surface Plasmons synthesized by both thermal evaporation and Radio Frequency (RF) magnetron sputtering system to tune and enhance optical absorption and scattering using the surface Plasmon resonance effect. The NPs were annealed at various temperatures and for different times to reconstruct and modify their shapes, sizes as well as the inter-particle distance (coverage).
Stability is of paramount importance in organic semiconductor devices. Serious degradation in air constrains their applications potential. The study further investigates the mechanisms that determine the stability of organic photovoltaic devices. Our results depict the degradation mechanisms and their circumvention through the use of high mobility pentacene to improve stability.
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Radiative decay and coupling of surface plasmons on metallic nanohole arrays. / 表面等離子體在金屬納米孔陣列的輻射衰減及耦合 / Radiative decay and coupling of surface plasmons on metallic nanohole arrays. / Biao mian deng li zi ti zai jin shu na mi kong zhen lie de fu she shuai jian ji ou heJanuary 2013 (has links)
了解表面等子體和外部環境之間的相互作用對表面等子體應用的開發非常重要。我們的研究集中在表面等子體與遠場的耦合,以及表面等子體模之間的耦合。 / 首先,我們研究由表面等子體模式耦合所產生的射衰變的變化。我們以角分辨反射光譜測同孔大小的納米孔陣上的簡併表面等子體模的衰減。對於每個孔的大小,我們觀察到在發生共振耦合的光譜區,衰減速有很大的改變,顯示出暗模和模的形成。耦合模很好地解釋衰變的變化。推導出的耦合常隨著孔直徑的增加而增加。我們也對耦合模一些有趣的特性及衰減變化的微觀起源進探討。 / 第二,我們以偏振分辨反射光譜從二維屬陣射散射。我們發現,反射光譜遵循的法模型可以由耦合模和瓊斯矩陣演算推導出。通過用正交方向的偏光器和分析器,反射光譜上的谷翻轉成峰,從以能夠測定出射散射效。我們發現,射散射效與波長和孔直徑的依賴關係和單孔的瑞散射相符合。 / 最後,我們開發一個新的方法,以偏振分辨光譜在實驗中測射衰變。這方法的有效性通過時域有限差分計算得到證明。我們還將此方法應用在實驗據上作為示範。 / Understanding the interaction between surface plasmon and outer environment is crucial in development of plasmonic applications. Our study is focused on the coupling between surface plasmons and far field, and also the coupling between surface plasmon modes. / First, we studied the change in radiative decay rate due to coupling of degenerate surface plasmon modes. We measured the decay rates of two degenerate surface plasmon modes in Au nanohole arrays with different hole sizes by angle-resolved reflectivity spectroscopy. For each hole size, at the spectral region where resonant coupling occurs, we observed a large modification in decay rates, leading to the formation of dark and bright modes. The change in decay rates is well explained by coupled-mode theory. The deduced coupling constant is found to increase with increasing hole diameter. Interesting properties of the coupled modes and microscopic origin of the change in decay rate is also discussed. / Second, we measured the radiative scattering from two-dimensional metallic arrays by using polarization-resolved reflectivity spectroscopy. We found that the reflectivity spectra follow the Fano-like model which can be derived from coupled-mode theory and Jones matrix calculus. By orthogonally orienting the incident polarizer and the detection analyzer, reflectivity dips flip into peaks and the radiative scattering efficiency can be determined accordingly. The dependence of total radiative scattering efficiency on wavelength and hole diameter is found to agree well with Rayleigh scattering by single hole. / Finally, we developed a new method to measure radiative decay rates experimentally by polarization-resolved reflectivity spectroscopy. The validity of this method is proved by finite-difference time-domain simulation. We also applied this method on experimental data as a demonstration. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Lo, Hau Yung = 表面等離子體在金屬納米孔陣列的輻射衰減及耦合 / 羅孝勇. / "December 2012." / Thesis (M.Phil.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 88-92). / Abstracts also in Chinese. / Lo, Hau Yung = Biao mian deng li zi ti zai jin shu na mi kong zhen lie de fu she shuai jian ji ou he / Luo Xiaoyong. / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Basic Theory and Techniques --- p.3 / Chapter 2.1 --- Macroscopic Maxwell Equations and Boundary Conditions --- p.3 / Chapter 2.2 --- Symmetries and Band Structure --- p.4 / Chapter 2.3 --- Coupled-mode Theory --- p.10 / Chapter 2.4 --- Finite-difference Time-domain Simulation --- p.12 / Chapter 2.5 --- Preparation of Metallic Nano-hole Arrays --- p.14 / Chapter 3 --- Fundamentals of Surface Plasmons on Metallic Nanohole Array --- p.18 / Chapter 3.1 --- Confinement and Propagation Nature of SPs --- p.18 / Chapter 3.2 --- Skin Depth and Propagation Length --- p.19 / Chapter 3.3 --- Dispersion Relation and Phase-matching Conditions --- p.21 / Chapter 3.4 --- Measurement of Band Structure: Angle-resolved Reflectivity Mapping --- p.23 / Chapter 3.5 --- Red Shift of Band Structure --- p.26 / Chapter 3.6 --- Comparison of Two Presentations of Band Structure: "ω against k" versus "λ against θ" --- p.28 / Chapter 3.7 --- Resonance Peak Shape: FanoModel and Wood's Anomalus --- p.30 / Chapter 3.8 --- Resonance Peak Shape: "Fano-like" Model --- p.34 / Chapter 3.9 --- Appendix A: Derivation of Eq(3.1) --- p.36 / Chapter 4 --- Decay Rates Modification though Coupling of Degenerate Surface Plasmon modes --- p.40 / Chapter 4.1 --- Introduction --- p.40 / Chapter 4.2 --- Measurements of Degenerate Surface Plasmon Modes --- p.42 / Chapter 4.3 --- Decay rates of Coupled Modes --- p.45 / Chapter 4.4 --- Hole Diameter Dependence of Coupling Constants --- p.47 / Chapter 4.5 --- Understanding the S-polarized Surface Plasmon Modes --- p.50 / Chapter 4.6 --- TE-like Surface Plasmon Modes --- p.53 / Chapter 4.7 --- Microscopic Origin of the Modification in Decay Rate --- p.54 / Chapter 4.8 --- Summary --- p.60 / Chapter 5 --- Direct Measurement of Radiative Scattering of Surface Plasmon Resonance from Metallic Arrays by Polarization-resolved Reflectivity Spectroscopy --- p.61 / Chapter 5.1 --- Introduction --- p.61 / Chapter 5.2 --- Theory of Direct Measurement of Radiative Scattering --- p.62 / Chapter 5.3 --- Comparison with Experiment --- p.65 / Chapter 5.4 --- Comparison with Rayleigh Scattering Model --- p.71 / Chapter 5.5 --- Summary --- p.74 / Chapter 6 --- A Method of Obtaining Radiative Decay Rates From Experiment --- p.76 / Chapter 6.1 --- Introduction --- p.76 / Chapter 6.2 --- Method --- p.77 / Chapter 6.3 --- Prove of Validity --- p.78 / Chapter 6.4 --- Experimental Demonstration --- p.82 / Chapter 6.5 --- Summary --- p.85 / Chapter 7 --- Conclusion --- p.86 / Chapter 8 --- Bibliography --- p.88 / Chapter 9 --- Curriculum Vitae --- p.93
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Plasmonic properties of gold nanorod-based oligomers and arrays. / 基於金納米棒組裝的寡聚體及陣列的表面等離子體共振特性研究 / CUHK electronic theses & dissertations collection / Plasmonic properties of gold nanorod-based oligomers and arrays. / Ji yu jin na mi bang zu zhuang de gua ju ti ji zhen lie de biao mian deng li zi ti gong zhen te xing yan jiuJanuary 2013 (has links)
Shao, Lei = 基於金納米棒組裝的寡聚體及陣列的表面等離子體共振特性研究 / 邵磊. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Shao, Lei = Ji yu jin na mi bang zu zhuang de gua ju ti ji zhen lie de biao mian deng li zi ti gong zhen te xing yan jiu / Shao Lei.
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Dependence of surface plasmon polaritons on the geometry of periodic metallic nanostructures and Its application on biosensing. / 表面等離子體激元對於週期性金屬納米結構幾何形狀的依賴性及其在生物傳感中的應用 / CUHK electronic theses & dissertations collection / Dependence of surface plasmon polaritons on the geometry of periodic metallic nanostructures and Its application on biosensing. / Biao mian deng li zi ti ji yuan dui yu zhou qi xing jin shu na mi jie gou ji he xing zhuang de yi lai xing ji qi zai sheng wu chuan gan zhong de ying yongJanuary 2012 (has links)
由於表面等離子體激元可以將電磁場限制在金屬表面,從而產生強烈的場強增強效果,因此在納米光子學和生物光子學方面具有廣泛的應用價值,其中包括高性能發光二級管、光伏電池、超高分辨率光學成像和超靈敏分子檢測等。尤其在單分子和醫學診斷方面,基於表面等離子體共振的生物傳感器獲得了越來越多的青睞。本論文包括兩部份。第一部份著重討論二維週期性洞陣列的表面等離子體特性,而第二部份則是研究這種洞陣列結構在表面等離子體共振傳感方面的應用。 / 在第一部份中,表面等離子體模式被分為非簡並模式(m,O) 和簡並模式(m,±n)兩種情況分別加以討論。首先,結合實驗結果和理論模型,我們對非簡並模式的衰減壽命和激發效率進行了研究。通過光干涉光刻法和薄膜沉積技術,一系列不同幾何結構的洞陣列樣品被製備出來,且這些樣品具有很高的重複性。利用角分辨色散關係進行模式識別以及確定這些模式的衰減壽命和激發效率。通過調整起偏器和檢偏器的相對方向,表面等離子體模式的非輻射和輻射衰竭均可加以研究。結果發現,衰減壽命強烈依賴於單洞的幾何結構,而且這種行為可以用簡單的靜電模型并考慮高階修正加以解釋。從非輻射衰減和輻射衰減平衡的角度出發,激發效率對幾何結構和共振波長的依賴性也可以理解。對於簡并模式,由於存在稱合,對稱模式和反對稱模式分別被p 偏振激發和S偏振激發。它們的對稱性和對於衰減壽命和共振波長的修正可以用干涉法和模式耦合理論來理解。最後,利用多模耦合方程,我們對色散關係圖譜隨著洞深度增加而演化的情況也進行了探討。 / 第二部份對基於表面等離子體共振的生物傳感器與陣列幾何結構的關係進行了研究。結果發現,激發效率和衰減壽命對表面等離子體共振傳感器的分辨率都起到了關鍵性作用。在共振中,峰值高度和帶寬主要由表面等離子體的衰減速率控制。較低的衰減速率導致較清晰的峰值線型,從而產生較高的傳感器分辨率。因此,通過調整陣列的幾何結構以產生非常低得輻射衰減速率,表面等離于體共振傳感器的品質因數可高達104.8/RIU ,這已經超過了基於梭鏡和納米粒子對應器件的性能表現。 / Surface plasmon polaritons (SPPs) generate a strong localized electromagnetic field on metal surface and thus are promising for nano- and bio-photonics including high performing light-emitting diodes and photovoltaic cells, super-high resolution optical imaging, ultra-high sensitive bimolecular detection, etc. In particular, the application of SPPs on surface plasmon resonance (SPR) biosensor has drawn much more attention recently because of the attempt to realize single molecule detection in medical diagnosis. / This thesis contains two parts. The first part focuses on studying the basic plasmonic properties of two-dimensional periodic hole arrays while the second part concentrates on the application of hole arrays on SPR sensing. / In the first part, SPPs modes on hole arrays are classified into nondegenerate mode (m, 0) and degenerate mode (m, ±n). For nondegenerate mode, its decay lifetime and generation efficiency are studied both experimentally and theoretically. By combining interference lithography and thin film deposition, a set of arrays with a wide range of geometry has been fabricated with high reproducibility. The dispersion relations of arrays are studied by angle-dependent reflectivity for mode identification and detenninations of SPP decay lifetime and generation efficiency. In particular, through orienting the polarization of the specular reflection either parallel or orthogonal to that of the incidence, we can access both the nonradiative and radiative decays of SPPs at different resonance wavelengths. As a result, it is found that decay lifetime is strongly dependent on the geometry of single hole and its behaviors can be understood by using a simple quasi-static model taking into account of the higher order correction as well as numerical simulation deduced by finite-difference timedomain. The dependence of generation efficiency on hole geometry or resonance wavelength can be understood in tenns of trade-off between nonradiative and radiative decay rates. Once these two decay rates equals to each other, the optimum generation efficiency is realized and the field enhancement gets the maximum. And the optimum parameters can be achieved by adjusting the hole geometry or the resonance wavelength. For degenerate mode, due to the coupling between (m, +n) and (m, -n) modes, a symmetric and an anti-symmetric modes are excited under pand s-polarized excitation, respectively. Their symmetries and modifications to the decay lifetime and resonance wavelength can be understood by using the interference method and coupled mode theory. Finally, generalized coupled mode equations are employed to know about the evolution of dispersion relation as hole depth increases. / The dependence of SPR biosensor on the generation and decay of SPPs are studied in the second part. Both the generation efficiency and decay lifetime of SPPs are found to be critical in governing the resolution of SPR biosensor. In SPR, the peak height and linewidth are primarily controlled by the decay rate of SPPs. Lower decay rate leads to sharper peak profile, which results in higher SPR resolution. Therefore, by tailoring the geometry of hole arrays to achieve a very low radiative decay rate, a SPR biosensor with figure of merit (FOM) reaching l04.8/RIU can be realized, which surpasses those of prism and nanoparticle counterparts. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Zhang, Lei = 表面等離子體激元對於週期性金屬納米結構幾何形狀的依賴性及其在生物傳感中的應用 / 張磊. / "November 2011." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 116-125). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Zhang, Lei = Biao mian deng li zi ti ji yuan dui yu zhou qi xing jin shu na mi jie gou ji he xing zhuang de yi lai xing ji qi zai sheng wu chuan gan zhong de ying yong / Zhang Lei. / Chapter Chapter1 --- Introduction --- p.1 / Chapter Chapter2 --- Theoretical Background --- p.7 / Chapter 2.1 --- Maxwell's equations --- p.7 / Chapter 2.2 --- Classic electromagnetic theory for dielectric properties of matter --- p.9 / Chapter 2.3 --- Surface plasmon polaritons at the dielectric/metal interface --- p.11 / Chapter 2.4 --- Excitation of surface plasmon polaritons --- p.16 / Chapter 2.4.1 --- Prism coupling --- p.17 / Chapter 2.4.2 --- Grating coupling --- p.17 / Chapter 2.5 --- lones calculus --- p.19 / Chapter 2.6 --- Finite-difference time-domain method --- p.22 / Chapter Chapter 3 --- Sample Preparation --- p.25 / Chapter 3.1 --- Interference lithography --- p.25 / Chapter 3.1.1 --- Substrate preparation --- p.26 / Chapter 3.1.2 --- Exposure --- p.27 / Chapter 3.1.3 --- Pattern development --- p.30 / Chapter 3.2 --- Thin film deposition --- p.30 / Chapter Chapter 4 --- Experimental Setups and Calibration --- p.33 / Chapter 4.1 --- Experimental setup for measuring dispersion relation --- p.33 / Chapter 4.2 --- Experimental setup calibration --- p.35 / Chapter 4.2.1 --- Calibration of spectrometer --- p.36 / Chapter 4.2.2 --- Calibration of movement stages --- p.38 / Chapter 4.3 --- Data presentation for dispersion relation --- p.40 / Chapter 4.4 --- Summary --- p.41 / Chapter Chapter 5 --- Understanding of Fundamental Properties of SPPs --- p.43 / Chapter 5.1 --- Excitation of SPPs on 2D hole arrays --- p.44 / Chapter 5.2 --- Properties of non degenerate modes and theoretical explanation --- p.53 / Chapter 5.2.1 --- Dependence of lifetime on hole geometry and theoretical explanation --- p.55 / Chapter 5.2.2 --- Dependence of generation efficiency on hole geometry and theoretical explanation --- p.63 / Chapter 5.3 --- Properties of degenerate modes and theoretical explanation --- p.70 / Chapter 5.3.1 --- Dependence of properties of degeneration modes on hole geometry by FDTD --- p.72 / Chapter 5.3.1.1 --- (0, ±l)[subscript s,a] modes --- p.72 / Chapter 5.3.l.2 --- (-1, ±l)[subscript s,a] modes --- p.76 / Chapter 5.3.2 --- Understanding of excitation of degenerate modes by using interference method --- p.79 / Chapter 5.3.3 --- Understanding of coupling between degenerate modes by using coupled mode theory --- p.85 / Chapter 5.4 --- Evolution of dispersion relation as hole depth increases --- p.90 / Chapter 5.5 --- Summary --- p.95 / Chapter Chapter 6 --- Surface Plasmon Resonance Based Label Free Biosensor --- p.98 / Chapter 6.1 --- Basics of surface plasmon resonance (SPR) based biosensor --- p.98 / Chapter 6.2 --- State-of-the-art SPR biosensor --- p.101 / Chapter 6.3 --- SPR biosensor by using 2D metallic hole arrays --- p.102 / Chapter 6.4 --- Summary --- p.111 / Chapter Chapter 7 --- Conclusions --- p.112 / References --- p.116 / Publications --- p.126
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Pseudo-one-dimensional nanostructures for photovoltaic, photocatalytic and plasmonic applications. / 準一維納米結構在光伏、光催化及等離子體激元方面的應用 / CUHK electronic theses & dissertations collection / Pseudo-one-dimensional nanostructures for photovoltaic, photocatalytic and plasmonic applications. / Zhun yi wei na mi jie gou zai guang fu, guang cui hua ji deng li zi ti ji yuan fang mian de ying yongJanuary 2012 (has links)
在本篇論文中,我們成功地在透明導電襯底上製備了一系列準一維納米材料陣列。我們首先製備了氧化鋅納米線陣列,然後把它們用作氧化鋅/硒化鎘核殼納米線纜陣列中的核以及合成硒化鎘和碲化鎘納米管陣列所需的犧牲模板。最後,金納米管陣列則是利用之前製備的硒化鎘納米管陣列為模板合成的。氧化鋅納米線陣列是通過高溫的熱蒸法和低溫的水熱法製備的。水熱法製備的氧化鋅納米線陣列的電導高於熱蒸法製備的氧化鋅納米線陣列,這使得水熱法製備的氧化鋅納米線更適合採用與電相關的後續處理方法。當氧化鋅納米線陣列被用作犧牲模板來製備納米管時,水熱法製備的氧化鋅納米線能被輕易地完全去除。基於這些認識,我們主要採用電化學沉積法在水熱法製備的氧化鋅納米線陣列表面沉積硒化鎘,得到了氧化鋅/硒化鎘核殼納米線纜陣列。接下來,我們將納米線纜陣列光電極和沉積了鉑催化劑的對電極組裝成三文治結構的太陽能電池。研究發現,採用多硫電解液的電池性能比碘基電解液的電池好,其中成分為1摩爾每升硫化鈉,1摩爾每升硫和1摩爾每升氫氧化鈉的多硫電解液的電池效率最高。當去除電化學沉積法生長的氧化鋅/硒化鎘和氧化鋅/碲化鎘核殼納米線纜陣列中的氧化鋅核以後,便在導電襯底上得到了硒化鎘和碲化鎘的納米管陣列。儘管兩種納米管陣列都對可見光有很強的吸收,但是,硒化鎘納米管陣列相比碲化鎘納米管陣列,表現出較高的光響應和較好的光催化降解亞甲基藍的活性。這是因為該樣品中的光生載流子能有效分離,同時能參與化學反應的表面積也較大。最後,我們選用硒化鎘納米管陣列作為模板,利用化學方法製備了金納米管陣列。金納米管的尺寸可以通過控制硒化鎘納米管模板來加以調節。當我們將具有拉曼活性的4-巰基苯甲酸分子吸附到金納米管的表面時,其拉曼散射相比未吸附時,顯著地增強了約四個數量級,如此大的提高來源於金納米管表面附近的局域電場增強效應。 / In this thesis, we demonstrated the synthesis of a series of pseudo-one-dimensional nanostructure arrays on transparent conducting substrates. We started with ZnO nanowire arrays, which were then served as the core for the ZnO/CdSe core/shell nanocable arrays formation. Further taking the ZnO as sacrificial templates led to the formation of CdSe (and CdTe) nanotube arrays. Finally, Au nanotube arrays were fabricated using the CdSe nanotube arrays as the template. ZnO nanowire arrays were synthesized via high-temperature thermal evaporation method (TE) and low temperature hydrothermal method (HT). The electrical conductivity of HT samples on the substrates was higher than that of the TE counterparts, making it attractive for further electrical-based processing. When serving as the sacrificial templates for nanotube fabrication, HT nanowires can be completely removed with ease. Based on these understanding, ZnO/CdSe core/shell nanocable arrays were obtained mainly via electrochemical deposition of CdSe on HT ZnO nanowire arrays. Nanocable-array-photoelectrode was assembled with a Pt-coated counter electrode into a sandwiched solar cell. Polysulfide electrolytes with various compositions were found to work better than iodine-based ones for such cells, and the cell with the polysulfide electrolyte containing 1 M Na₂S, 1 M S and 1 M NaOH showed highest efficiency. Removal of the ZnO cores in the electrodeposited ZnO/CdSe and ZnO/CdTe nanocable arrays left CdSe and CdTe nanotube arrays on the conducting substrate. Although strong visible-light absorption was observed from both two nanotube arrays, higher photocurrent and better photocatalytic degradation activity of methlyene blue were recorded from CdSe-nanotube-array samples (as compared to the CdTe ones), owing to effective charge separation and large surface area for chemical reactions. Lastly, Au nanotube arrays were synthesized via chemical method using CdSe nanotube arrays as the template. The dimensions of the Au nanotubes, as replicated from CdSe nanotubes, were tunable. When absorbed on the Au nanotube arrays surface, the Raman scattering of 4-mercaptobenzoic acid (a Raman-active molecule) was greatly enhanced for~4 orders of magnitude compared to the signals from the dry powder of the same molecule. Such large increase was due to the strong local electrical field enhancement near the Au nanotubes surface. / Detailed summary in vernacular field only. / Zhu, Haojun = 準一維納米結構在光伏、光催化及等離子體激元方面的應用 / 朱浩君. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 141-168). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Abstracts in English and Chinese. / Zhu, Haojun = Zhun yi wei na mi jie gou zai guang fu, guang cui hua ji deng li zi ti ji yuan fang mian de ying yong / Zhu Haojun. / Abstract --- p.i / 摘要 --- p.iii / Acknowledgements --- p.iv / Contents --- p.v / List of Figures --- p.viii / List of Tables --- p.xviii / Chapter Chapter 1 --- Introductions --- p.1 / Chapter Chapter 2 --- Background --- p.4 / Chapter 2.1. --- Nanostructured Photovoltaic (PV) Solar Cells --- p.4 / Chapter 2.1.1. --- Fundamental physics of nanostructures for solar cell applications --- p.5 / Chapter 2.1.2. --- Inorganic nano-architectures for PV cells --- p.9 / Chapter 2.2. --- Nanostructures for Photocatalytic Degradation of Organic Pollutants --- p.18 / Chapter 2.2.1 --- Overview of photocatalytic degradation of organic pollutants --- p.19 / Chapter 2.2.2 --- Photocatalysis under visible light illumination --- p.24 / Chapter 2.3. --- Plamonic Noble Metal Nanostructures --- p.29 / Chapter 2.3.1 --- Surface plasmons of noble metal nanostructures --- p.29 / Chapter 2.3.2 --- Applications of plasmonic noble metal nanostructures in solar energy conversion and sensing --- p.35 / Chapter Chapter 3 --- Methodologies and Instrumentations --- p.45 / Chapter 3.1. --- Materials Growth Methodologies --- p.45 / Chapter 3.1.1. --- Thermal evaporation (TE) methods --- p.45 / Chapter 3.1.2. --- Hydrothermal (HT) methods --- p.47 / Chapter 3.1.3. --- Electrodeposition (ED) methods --- p.49 / Chapter 3.1.4. --- Prototype solar cells assemble --- p.52 / Chapter 3.2. --- Characterization Techniques --- p.53 / Chapter 3.2.1. --- Morphological, structural, and compositional analysis using electron microscopy based techniques --- p.53 / Chapter 3.2.2. --- Photoelectrochemical (PEC) performance test --- p.63 / Chapter 3.2.3. --- Photocatalytic degradation of organic pollutants --- p.65 / Chapter 3.2.4. --- Single-particle scattering imaging and spectroscopy --- p.67 / Chapter Chapter 4 --- ZnO Nanowire Arrays on Conducting Substrates -- A Comparison on the Growth Methodology --- p.71 / Chapter 4.1. --- Introduction --- p.71 / Chapter 4.2. --- Experimental --- p.72 / Chapter 4.3. --- Results and Discussions --- p.75 / Chapter 4.3.1 --- Morphologies, crystal structures and chemical compositions --- p.75 / Chapter 4.3.2 --- ZnO nanowire arrays used as electrodes --- p.80 / Chapter 4.3.3 --- ZnO nanowire arrays used as sacrificial templates in electroplating . --- p.85 / Chapter 4.4. --- Conclusions --- p.88 / Chapter Chapter 5 --- ZnO-core/CdSe-shell Nanocable Arrays for Photovoltaic Solar Cells --- p.89 / Chapter 5.1. --- Introduction --- p.89 / Chapter 5.2. --- Experimental --- p.90 / Chapter 5.3. --- Results and Discussions --- p.93 / Chapter 5.3.1 --- Synthesis of the ZnO-core/CdSe-shell nanocable arrays on ITO/glass --- p.93 / Chapter 5.3.2 --- The photovoltaic (PV) performance --- p.100 / Chapter 5.4. --- Conclusions --- p.107 / Chapter Chapter 6 --- CdSe and CdTe Nanotube Arrays as Visible-light-driven Photocatalyst for Organic Pollutant Degradation --- p.108 / Chapter 6.1. --- Introduction --- p.108 / Chapter 6.2. --- Experimental --- p.109 / Chapter 6.3. --- Results and Discussions --- p.112 / Chapter 6.3.1. --- Morphology, crystal structure, and chemical composition of the nanotube arrays --- p.112 / Chapter 6.3.2. --- Optical properties --- p.116 / Chapter 6.3.3. --- Photoelectrochemical (PEC) performance --- p.117 / Chapter 6.3.4. --- Photocatalytic activities --- p.120 / Chapter 6.4. --- Conclusions --- p.123 / Chapter Chapter 7 --- Fabrication of Au Nanotube Arrays and Their Plasmonic Properties --- p.124 / Chapter 7.1. --- Introduction --- p.124 / Chapter 7.2. --- Experimental --- p.125 / Chapter 7.3. --- Results and Discussions --- p.127 / Chapter 7.3.1. --- Morphology, crystalline structure, and chemical composition of Au nanotube arrays --- p.127 / Chapter 7.3.2. --- Au nanotube formation mechanism --- p.129 / Chapter 7.3.3. --- Plasmonic properties of Au nanotube arrays on ITO/glass substrates --- p.131 / Chapter 7.3.4. --- Plasmonic properties of single Au nanotubes --- p.133 / Chapter 7.3.5. --- Au nanotube arrays on ITO/glass as SERS substrates --- p.134 / Chapter 7.4. --- Conclusions --- p.138 / Chapter Chapter 8 --- Conclusions --- p.139 / Bibliography --- p.141
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