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Localized Surface Plasmon Enhanced Green-Yellow Light Emission of the ZnO Nanorod Arrays Using Metal Island Film
No full text在本論文中，我們利用水熱法於金跟銀上合成出高指向性的柱狀氧化鋅。 在第一部分，我們觀察成長於鍍金矽基板上的柱狀氧化鋅。我們發現到金膜上金顆粒有助於氧化鋅的成長。在X光繞射部分，我們發現到此柱狀氧化鋅結構對於(103)面有高指向性。 透過區域化表面電漿共振的效果，成功的提高了柱狀氧化鋅在缺陷部份的放光。 透過金的幫助下，在光激螢光我們觀察到可能光/紫外光的放光比有將近107倍的加強。可見發光的波峰部分，可以觀察到逐漸由570 nm 紅移到 600nm，這是由於金的區域化表面共振散射長波長共振帶所導致的結果。而在陰極電子激螢光部分，也顯示出與光激螢光相同的結果。 第二部分，我們同樣地利用水熱法在鍍銀的矽基板上成長高指向性柱狀氧化鋅。掃描式電子顯微鏡觀察到銀的膜厚與金屬顆粒有正比趨勢。在X光繞射譜，我們發現此柱狀氧化鋅對於(002)面有高指向性。透過光激螢光的分析，銀對於缺陷放光的則加強在波長500nm附近。透過以上分析，我們證實了區域化表面電漿共振與金屬的顆粒大小有很大的相依性，並且根據金屬的顆粒及種類，會分別加強不同波長的放光。 而發光的強度與金屬膜厚的趨勢則是正相關。In this thesis, we synthesized the high orientation ZnO nanorods array by hydrothermal process. First, we studied the ZnO on the Au-coated Si substrate. The diameter of ZnO arrays could be controlled with the aid of Au island films as a catalyst. The X-ray diffraction investigation indicated that the epitaxy of the ZnO array preferred to grow along the plane (103). Defect-level emission was greatly enhanced due the localized surface plasmon resonance of Au island film coupled with ZnO array. The intensity ratio of visible/UV was enhanced 107 times with the aid of Au island films. The enhanced DLE redshift from 570 to 600 nm confirms that the PL enhancement arises mostly from the effective scattering of the LSP in the longer wavelength range of in-plane resonance band. Second, we demonstrate that vertical well-aligned crystalline ZnO nanorods arrays were grown on Ag/Si substrates by hydrothermal process. Different thicknesses of Ag films on Si substrates were prepared by e-gun evaporator. The morphology of Ag films were observed by the scanning electron microscopy. The XRD of ZnO on Ag islands result indicated that the epitaxy will grow along the plane (002). The Ag films have help for the enhancement of the emission at around 500nm. We prove that the LSP resonance depends on the size of the metal and the LSP resonance only happens at specific wavelength. The effect of the LSP varies with both the intensity and wavelength of DLE.摘要 ivbstract ivcknowledgement ivontents ivist of figures vihapter 1 : Introduction 1.1 Nanotechnology 1.2 Self-Assembly 3.3 1-D Semiconducting Structures 4.4 Zinc oxide (ZnO) Nanostructures 6.5 Hydrothermal 7.6 Localized Surface Plasmon Resonance (LSPR) 9.7 Scope and Aim of the Thesis 10.8 References 11hapter 2 : Experimental 14.1 Growth of the ZnO Nanorods 14.2 Scanning Electron Microscope (SEM) 16.3 Transmission Electron Microscopy (TEM) 17.4 X-ray Diffraction (XRD) 21.5 Photoluminescence (PL) 23.6 References 27hapter 3: Localized Surface Plasmon Enhanced Green-Yellow Light Emission of the ZnO Nanorod Arrays Using Au Island Film 28.1 Introduction 28.2 Experimental 29.3 Results and Discussions 29.3.1 Structural Characterization 30.3.2 PL 33.3.3 CL 38.4 Summary 39.5 References 60hapter 4: Localized Surface Plasmon Enhanced Green-Blue Light Emission of the ZnO Nanorod Arrays Using Ag Island Film 62.1 Introduction 62.2 Experimental 63.3 Result and Discussion 64.3.1 Sample preparation 64.3.2 X-Ray Diffraction (XRD) Analysis 65.3.3 Surface Plasmon Characterization 65.3.4 Emission Enhancement 66.4 Summary 71.5 References 82hapter 5: Conclusions 84hapter 6: Future Work-ZnO nanowire dye-sensitized solar cell 86.1 Introduction 86.2 Approach 88.3 References 8
Solar Energy-Harvesting Schemes via Nanostructures
No full text第一個工作我們利用水熱法成長氧化鋅奈米線在市售五吋單晶矽太陽能電池上。其附合結構，包含氧化鋅奈米線/氮化矽抗反射層/微米坑洞，使電池的短路電流提升到38.45毫安培/每平方公分，開路電壓609毫伏特，及光電轉換效率14.04%，在高角度60度光入射測試只有損失5.3%的短路電流。在第二個工作，我們使用奈米球製作奈米柱與奈米牆複合結構作為抗污封裝玻璃，經過六星期的戶外測試，電池仍能可以維持98.8%原本的效率。第三個工作我們利用硒化銅銦鎵量子點設計梯流效應降低染料敏化太陽能電池的暗電流，使電池的短路電流提升到15.27毫安培/每平方公分，開路電壓762毫伏特，及光電轉換效率8.02%，最後一個工作我們利用氮參雜的石墨烯搭配白金作為背電極，其梯流效應，高催化特性及高反射率使得染料敏化太陽能電池的光電轉換效率得到大幅的提升。In first work, we employ a ZnO nanorod/Si3N4-coated Si microgroove-based hierarchical structure (HS) for a light-harvesting scheme in 5 inch single crystalline Si solar cells. ZnO nanorods and Si microgrooves were fabricated by a simple and scalable aqueous process. The excellent light-harvesting characteristics of the HS, such as broadband working ranges and omnidirectionality have been demonstrated using external quantum efficiencies and reflectance measurements. The solar cells with the hierarchical surface exhibit excellent photovoltaic characteristics, i.e., a short-circuit current (JSC) of 38.45 mA/cm2, open-circuit voltage of 609 mV and conversion efficiency of 14.04%. As incident angles increase from 0o to 60o, only 5.3% JSC loss is achieved by employing the hierarchical surface, demonstrating the enhanced omnidirectional photovoltaic performances, also confirmed by the theoretical analysis. A viable scheme for broadband and omnidirectional light harvesting using the HS employing microscale/nanoscale surface textures on single crystalline Si solar cells has been demonstrated. In second work, fused-silica packaging glass fabricated with a hierarchical nanostructure was found to exhibit superior antireflective and self-cleaning properties. The nanostructure was achieved by colloidal lithography and reactive ion etching techniques, displaying the stacking of ultra-thin nanorods on top of nanowalls. Commercial Si solar cells covered with the hierarchically structured packaging glass exhibit enhanced photovoltaic performances, and the enhancement becomes increasingly prominent after 6 weeks of outdoor exposure. Similar improved performances were attained by GaAs-based solar cells with the same hierarchical glass. The enhanced device performances indicate that the nanostructured surface can effectively repel polluting dust/particles and facilitating optical waves propagating through the fused-silica, which was confirmed by numerical analyses. In third work, Ga-rich CuIn(1-x)GaxSe2(CIGS) quantum dots (QDs) with a wide bandgap of 1.58eV were utilized in dye-sensitized solar cells for energy harvesting. Ga-rich CIGS QDs at TiO2 photoanodes afford the recombination reduction and thus suppress the dark current, leading to the increase of short-circuit current from 14.47 to 15.27 mA/cm2 and open-circuit voltage from 751 to 762mV. This is due to well-adjusted conduction band minimum of Ga-rich CIGS QDs between that of TiO2 and excited state oxidation potential of N719, enhancing the photoelectron collection and suppressing electron back-transfer from TiO2 to oxidized redox species in the electrolyte. In final work, nitrogen-doped graphene (NGR) was utilized in dye-sensitized solar cells for energy harvesting. NGR on Pt-sputtered fluorine-doped tin oxide substrate (NGR/Pt/FTO) as counter electrode (CE) achieves the high efficiency of 9.38% via the nitrogen doping into graphene. This is due to (i) the hole-cascading transport at the interface of electrolyte/CEs via controlling valence band maximum of NGR located between the redox potential of I-/ I- redox couple and the Fermi level of Pt by nitrogen doping, (ii) the extended electron transfer surface effect provided by large-surface-area NGR, (iii) the high charge transfer efficiency due to superior catalytic characteristics of NGR via nitrogen doping, and (iv) the superior light-reflection effect of NGR/Pt/FTO CEs, facilitating the electron transfer from CE to I3- ions of the electrolyte and light absorption of dye. The result demonstrated that the NGR/Pt hybrid structure is promising in the catalysis field.
Keywords: antireflective coating, ZnO nanorods, dye-sensitized solar cell, nitrogen-doped graphene, CIGS, quantum dot.口試委員審定書
誌謝…………………………………………………………………………………….i
中文摘要………………………………………………………………………………ii
ABSTRACT…………………………………………………………………………..iii
CONTENTS…………………………………………………………………………..iv
LIST OF FIGURES…………………………………………………………………...vi
LIST OF TABLES……………………………………………………………………vii
Chapter 1 Introduction ………………………………………………………………1
Chapter 2 A Efficient Broadband and Omnidirectional Light-Harvesting Scheme Employing a Hierarchical Structure Based on a ZnO Nanorod/Si3N4-coated Si Microgroove on 5-inch Single Crystalline Si Solar Cells…………………………..3
2.1 Introduction
2.2 Experimental
2.3 Results and discussion
2.4 Summary
2.5 References
2.6 Supporting information
Chapter 3 Enhancement of Omnidirectional and Self-Cleaning Properties Employing the Hierarchical Packaging Glass for Solar Cells…………………...38
3.1 Introduction
3.2 Experimental
3.3 Results and discussion
3.4 Summary
3.5 References
3.6 Supporting information
Chapter 4 An Energy-Harvesting Scheme Utilizing Ga-Rich CuIn(1-x)GaxSe2 Quantum Dots for Dye-Sensitized Solar Cells………….………………………..74
4.1 Introduction
4.2 Experimental
4.3 Results and discussion
4.4 Summary
4.5 References
4.6 Supporting information
Chapter 5 Nitrogen-Doped Graphene/Pt Counter Electrodes for Dye-Sensitized Solar Cells…………………………………………..……………………...……….96
5.1 Introduction
5.2 Experimental
5.3 Results and discussion
5.4 Summary
5.5 References
5.6 Supporting information
Chapter 6 Conclusion …………………………………………….……………….125
Curriculum Vita
The Influence of Boundary Layer Processes on Advection Fog
No full text本研究探討邊界層之環境特徵和物理過程對平流霧維持之影響。初始條件由金門平流霧觀測實驗資料簡化而來，呈現近飽合的潮濕邊界層和逆溫結構，可影響垂直混合與霧頂長波輻射冷卻作用。並使用渦度方程建立的雲解析模式以4公尺高解析度進行一系列理想化的大渦流實驗。在透過開關特定物理過程來探討物理過程的模擬結果中，地表通量在霧已形成後具有較小的影響力且作用僅限於近地層;長波輻射冷卻能有效的增加霧水，但在此個案的環境中無法有效產生紊流動能;太陽輻射是使霧消散的重要機制，其加熱霧層並減少霧水;垂直風切加強霧層內的混合作用並擴大霧層的垂直分布，且在此個案中的紊流動能貢獻分布上，風切的貢獻遠重要於浮力的貢獻。在探討環境條件的模擬結果中，垂直風切強度可由臨界理查森數(Ri=0.25)分為強、弱垂直風切兩類，強垂直風切會將穩定層化邊界層調整成混合邊界層，並使霧層上移而變成層雲，但在弱垂直風切時，霧層則能夠穩定地維持。最後探討風切和海溫交互作用的影響，發現在弱垂直風切時(Ri > 0.25)，冷海溫的冷卻作用能加強霧層的穩定度並明顯的增加霧水;而高海溫的加熱作用則會破壞逆溫結構，將邊界層調整成混合邊界層並使霧層消散;而在強垂直風切時(Ri < 0.25)，冷海溫無法有效地透過冷卻作用建立逆溫結構，雖層雲中液態水含量增多，但仍無法使層雲下降而成霧;而暖海溫的加熱作用則更加增厚混合邊界層的厚度並減少了層雲中的雲水含量。海溫作用所需的反應時間較紊流混合作用長，因此海溫作用調整邊界層結構的效果並不如風切的作用。本研究指出環境近地面風場和與紊流傳送作用對平流霧結構有最明顯的影響，因此在使用區域模式模擬平流霧時，所選取的邊界層和紊流參數化以及垂直解析度配置能否正確呈現穩定層化與混合邊界層之間的轉換，是決定模擬結果的關鍵因素。This study investigates the influences of boundary layer (BL) processes and the environmental conditions on the maintenance of advection fog through idealized large-eddy simulations. The initial conditions were simplified from the in-situ sounding data during the fog episode at Kinmen Island. A near saturated moist layer with temperature inversion is throughout the domain, which represents the characteristics of advection fog. This kind of vertical profile of moisture can influence the effects of turbulent mixing and longwave radiative cooling at fog top. A series of idealized large-eddy simulations were carried out using the Vector Vorticity equation cloud-resolving model at a high resolution of 4 m. By turning on/off selected physical processes, the results show that surface heat and moisture fluxes have little influence on liquid water content and are restricted to surface layer when the fog layer already exists. Longwave radiative cooling is the dominant process to generate fog water but in this case cannot effectively generate turbulent kinetic energy (TKE) through buoyancy flux due to the specific environmental moisture condition. Solar radiation heats and evaporates the liquid water content within the fog layer. Vertical wind shear enhances the turbulent mixing and extents the vertical distribution of fog layer. Vertical wind shear also drives the shear instability, and the averaged magnitude of shear production of TKE is much larger than that of buoyancy production of TKE in this case. As to evaluate the impact of environmental wind profiles on the maintenance of the fog layer, Richardson number (Ri) is identified as the critical parameter. The stronger vertical wind shear (Ri < 0.25) modifies the boundary layer from a stable boundary layer to a well-mixed boundary layer. As a result, the fog layer no longer maintains but shifts upward into stratus cloud. In contrast, the fog layer can maintain under the condition of weaker vertical wind shear (Ri > 0.25). Lastly, the sensitivity of the fog layer structure to both the environmental vertical wind shear and sea surface temperature (SST) is investigated. Results show that the combination of weaker vertical wind shear (Ri > 0.25) and colder SST is favorable to the maintenance of fog. However, warmer SST dissipates the fog layer in the condition of weaker vertical wind shear (Ri > 0.25). On the other hand, fog layer cannot exist in the condition of stronger vertical wind shear (Ri < 0.25) whether the SST is colder or warmer. This study suggests that the vertical profile of wind speed and the effect of turbulent transport have the most significant influence on the structure of advection fog. Therefore, when simulating the advection fog by regional models, the results would highly depend on whether the chosen BL and turbulence parameterization schemes and vertical resolution can accurately represent the transition between a stable and well-mixed BL
An Efficient Temporal Model for Action Recognition Using Multivariate Linear Prediction
No full text對於辨識長時間的動作，時間之間的高階依賴關係非常有用，但是利用高階依賴關係，將造成常用的圖形時間模型像是HMM或者是CRF的模型計算複雜度很大程度的提升。本論文提出使用多變數線性預測，來利用時間上高階依賴關係。我們時間模型的計算複雜度比較低。除此之外，相較於圖形時間模型，我們的演算法不用定義與人工標記狀態，並且在有一定程度雜訊的Bag-of-Word 表示法上可以改善辨識率，而這個表示法在前人的研究中得到顯著的成果。我們的方法也擁有很好的應用能力，為了顯示這個能力，我們不僅在視訊資料上像是KTH和UCF資料庫實驗，同時也在骨架資料上像是MSR、Kinect資料庫實驗。在大多數情況，我們得到相較於世界上最先進的系統更好的結果。To recognize temporally extended actions, it is useful to introduce high-order temporal dependence into the recognition task. However, this will highly increase the computational complexity, when the commonly used graphical models such as HMM and CRF are employed. In this thesis, multivariate linear prediction is proposed to exploit high-order temporal dependence with lower computational complexity. In addition, our method makes no effort on defining and manually labeling states and can improve bag-of-word representations, which may contain considerable noise but has shown excellent performance in previous work. To show the applicability of the proposed method, we experiment not only on video datasets including KTH and UCF but on skeleton datasets such as MSR 3D action and UCF Kinect. In most of them, our method gets superior performance than the state-of-the-art methods
Surface profile-controlled close-packed Si nanorod arrays for self-cleaning antireflection coatings
No full text
Use of Acupuncture and Cupping in patients awaiting Total Knee Arthroplasty (TKA) due to Osteoarthritis of the Knee: Randomized Controlled Clinical Trial
No full textA osteoartrite é a doença articular crônica mais prevalente no mundo. De natureza degenerativa e inflamatória, é considerada uma das dez principais afecções causadoras de incapacidade que acometem a população mundial. Sua incidência é maior nas pessoas acima de 50 anos de idade, comprometendo a qualidade de vida, gerando prejuízos diretos e indiretos à economia. Dentre todas as articulações possíveis de desenvolverem esta doença, o joelho é o segmento mais comumente afetado. Normalmente, manifesta-se com dor de início insidioso e gradativo, e que muitas vezes está acompanhada de rigidez articular e perda funcional. A Acupuntura é uma opção terapêutica não farmacológica descrita na literatura, no entanto sua eficácia no tratamento dessa condição específica ainda é controversa. O objetivo deste trabalho é de contribuir com a literatura mundial no que diz respeito à eficácia da Acupuntura na osteoartrite de joelho, e investigar se há algum incremento de benefício, quando associado ao uso da Ventosaterapia. Cento e vinte pacientes aguardando tratamento cirúrgico do ambulatório de joelho do IOT-HCFMUSP foram convidados para participarem do projeto. Foram aplicados os critérios de inclusão e exclusão, e os que aceitaram assinaram o Termo de Consentimento Livre e Esclarecido (TCLE), e posteriormente foram alocados nos grupos existentes: Grupo A Acupuntura Sham + Ventosa Sham; Grupo B - Acupuntura Sham + Ventosa Verdadeira; Grupo C - Acupuntura Verdadeira + Ventosa Sham; Grupo D Acupuntura Verdadeira + Ventosa Verdadeira. Foram utilizados os questionários de Western Ontario and McMaster Osteoarthritis Index (WOMAC) que avaliam dor, rigidez e funcionalidade, e também foi registrada a quantidade de analgésicos e/ou anti-inflamatórios utilizada durante o período da pesquisa. A combinação da Acupuntura com a Ventosaterapia demonstrou melhora dos níveis de dor (EVA) e diminuição da quantidade do uso de medicamentos para dor dos pacientes com osteoartrite avançada do joelhoOsteoarthritis is the most prevalent chronic joint disease in the world. As degenerative and inflammatory nature, it is considered one of the 10 main disabling conditions that affects the world population. Its incidence is higher in people over 50 years old, compromising the quality of life, causing direct and indirect damage to the economy. Among all the possible joints to develop this disease, the knee is the most commonly affected segment. It usually presents with pain of insidious and gradual onset, which is often accompanied by joint stiffness and functional loss. Acupuncture is a non- pharmacological therapeutic option described in the literature, however, its efficacy in the treatment of this specific condition is still controversial. The objective of this work is to contribute to the world literature regarding the effectiveness of Acupuncture in knee osteoarthritis, and if there is any increase in benefit when associated with the use of Cupping Therapy. 120 patients waiting for surgical treatment from the knee outpatient clinic of the IOT-HCFMUSP were invited to participate in the project. Inclusion and exclusion criteria were applied, and those who accepted signed an informed consent form (ICF), and later allocated to the existing groups: A. Group A Acupuncture Sham + Cupping Sham; B. Group B - Acupuncture Sham+ True Cupping; C. Group C - True Acupuncture + Cupping Sham; D. Group D True Acupuncture + True Cupping. The Western Ontario and McMaster Osteoarthritis Index (WOMAC) questionnaire was used, which assesses pain, stiffness and functionality, and the number of analgesics and/or anti-inflammatory drugs used during the research period was also recorded. The combination of Acupuncture with Cupping Therapy demonstrated pain improvement by Visual Analogue Score (VAS) and decrease the amount of pain medication used by patients with advanced knee osteoarthriti
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Acupuncture effects on symptoms of depression, menopause and sleep quality for women battling breast cancer: a randomized controlled pilot study
No full textNesta tese a terapia com acupuntura é utilizada para mitigar os sintomas induzidos pelo bloqueio hormonal a que pacientes com câncer de mama são rotineiramente submetidas. O protocolo de pontos de acupuntura selecionado tem por base a teoria da Medicina Tradicional Chinesa sobre o aparecimento da miríade de sintomas que compõem a síndrome climatérica. Sessenta mulheres com diagnóstico de câncer de mama que se encontravam em uso de tamoxifeno foram divididas em três grupos, um grupo foi submetido a tratamento com acupuntura por 10 sessões semanais, outro foi submetido a intervenção simulada (sham) também por 10 sessões semanais e o terceiro grupo permaneceu sem intervenção específica por 10 semanas (lista de espera). A intensidade dos sintomas foi aferida através de escalas voltadas à avaliação de depressão, qualidade do sono e sintomas relacionados à menopausa. Os resultados mostram maior controle dos sintomas no grupo que foi submetido à acupuntura em comparação com os demais grupos, sendo essa diferença não só estatisticamente significante como também com grande tamanho de efeito indicando a possibilidade do uso desta terapia na otimização da qualidade de vida durante o tratamento do câncer de mamaIn this study, acupuncture therapy is used to mitigate the symptoms induced by the hormonal blockade to which breast cancer patients are routinely submitted. The selected acupuncture point protocol is based on the theory of Traditional Chinese Medicine on the appearance of the myriad of symptoms that make up the climacteric syndrome. Sixty women diagnosed with breast cancer who were using tamoxifen were divided into three groups, one group was submitted to acupuncture treatment for 10 weekly sessions, another one was submitted to sham intervention also for 10 weekly sessions and the third group was monitored without specific intervention for 10 weeks (waiting list). The intensity of symptoms was measured using scales aimed at assessing depression, sleep quality and symptoms related to menopause. The results show greater control of symptoms in the group that underwent acupuncture compared to the other groups, and this difference is not only statistically significant but also with a large effect size, indicating the possibility of using this therapy to optimize quality of life during breast cancer treatmen
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