ZnO/TiO_2复合纳米材料的制备及其在染料敏化太阳电池中的运用

本文在长有ZnO纳米粒子作为"种子层"的FTO基底上用水热合成法制备了取向高度一致的ZnO纳米线阵列,用TiCl4的异丙醇溶液在ZnO纳米线阵列的表面生长了纳米结构的TiO2。利用扫描电子显微镜、能量散射谱、X射线衍射分别表征纳米材料的形貌和结构,用Raman光谱研究了材料的晶格结构特性。染料敏化太阳电池的性能测试表明,与纯ZnO作为光阳极相比,ZnO/TiO2复合纳米材料作为光阳极的器件,开路电压和填充因子都得到了提高。     

采用亲水性聚合物阴极界面层的聚合物太阳电池

聚合物太阳电池由于具有质量轻、柔性好、生产成本低和可能实现大面积加工的独特优势,而受到国内外学者广泛的关注,成为研究的热点。聚合物太阳电池的性能强烈依赖于活性层和界面层的性能,其中可以通过改变界面层材料的结构和调节界面层的加工工艺等方法使光伏性能得到优化。近来,亲水性聚合物作为阴极界面层实现高性能有机光电器件表现出了独特的优势和巨大的潜力。重点介绍了采用亲水性聚合物作为阴极界面层提升聚合物太阳电池性能的最新进展。引入亲水聚合物可以调节多种阴极材料的功函数来增强电子收集,对于正装和倒装两种器件结构的聚合物太阳电池,都可以提升开路电压、短路电流、填充因子3个电池参数,而显著提高聚合物太阳电池的效率。     

全无机CsPbBr3钙钛矿太阳电池的研究进展

自2009年第一次报道以来,有机-无机杂化钙钛矿太阳电池(PSCs)的光电转换效率(PCE)从3.8％提升至25.5％,已可以与商业化的晶体硅太阳电池相媲美,引起全世界研究者的极大关注.然而,由于杂化物晶体结构中有机成分弱的化学键,器件长期稳定性受到很大的影响.近年来,用无机Cs+完全取代有机基团构成全无机卤化物钙钛矿被认为是解决太阳电池稳定性问题的有效途径.在Cs基钙钛矿之中,CsPbBr3具有最优异的耐热、耐光、耐湿性能,作为顶电池具有与晶体硅太阳电池组成长寿命叠层太阳电池的潜力.本文系统地综述了CsPbBr3 PSCs领域的研究进展,首先介绍了CsPbBr3 PSCs的发展历史及CsPbBr3的晶体结构和基本特性,随后阐述了CsPbBr3薄膜的制备方法、CsPbBr3的元素掺杂改性、器件的界面工程等方面的研究进展;最后,讨论了当前存在的问题和提高CsPbBr3 PSCs性能的未来方向,为进一步推动钙钛矿太阳电池的实用化进程提供参考.     

有机共混结构太阳电池的稳定性

有机共混结构太阳电池由于质轻、价廉、柔性,受到人们的广泛关注。随着有机共混结构太阳电池的能量转换效率的不断提高,其性能的稳定性也受到人们的重视。文中从太阳光、空气中的氧气和水分等因素对有机共混结构太阳电池的电极、活性层等的作用来说明这些因素对有机共混结构太阳电池稳定性的影响,阐述了影响有机太阳电池稳定性的原因,提出了解决有机共混结构太阳电池稳定性的方法,为高性能、高稳定性的有机共混结构太阳电池的研究提供有价值的参考。     

柔性薄膜太阳电池的研究进展

综述了近年来柔性薄膜太阳电池的发展状况,结合柔性薄膜太阳电池的发展历史,分析了用作柔性衬底薄膜太阳电池的研究成果,探讨了各种器件结构的优缺点,并介绍了柔性衬底材料的选择及柔性太阳电池的研究进展。     

有机-无机杂化光电导电极修饰材料研究进展

有机太阳电池(OPVs)和有机发光二极管(OLEDs)的阴极界面通常由有机小分子、聚电解质以及低温溶胶-凝胶法加工的金属氧化物(最常见的为ZnO)制备而成,由于这些材料导电性不佳使光电器件中阴极界面薄膜厚度限制在30 nm以下,给大面积生产提出了苛刻要求。有机-无机杂化的光电导材料是近来提出的有效提高阴极界面材料电导率的新策略。有机分子具有较高的消光系数,能够在低掺杂浓度下高效吸收可见光,而金属氧化物具有较高的电子迁移率,从有机分子到金属氧化物的光致电子转移能够有效填充金属氧化物中的电子陷阱(缺陷),同时大幅度增加金属氧化物中的载流子密度,因而,这种有机-无机杂化的电极修饰材料具有优异的光电导性能。最近,报道通过掺杂一类苝酰亚胺光敏剂到无定形ZnO薄膜中,显著提高ZnO薄膜在光照下的电导率,解决了ZnO薄膜电导率低的科学问题。将这种杂化的光电导材料用于OPVs与OLEDs器件中,显著提高了器件性能,同时大幅度降低了电极修饰薄膜厚度对器件性能的影响,为大面积器件的快速制备提供了有利条件。     

共轭聚合物受体光伏材料和全聚合物太阳电池

全聚合物太阳电池(all-PSCs)由p-型共轭聚合物给体和n-型共轭聚合物受体共混活性层夹在ITO透明电极和金属顶电极之间所构成,除具有一般有机太阳电池器件结构简单、质量轻、可以制备成柔性和半透明器件等优点外,还具有形貌和光照稳定性好及抗弯折性能高等突出特点,最近成为有机太阳电池领域的研究热点。给体和受体光伏材料的吸收互补和能级匹配是获得高效all-PSC的关键。本文将介绍n-型共轭聚合物受体光伏材料的发展历史,重点介绍最近发展的窄带隙小分子受体高分子化的聚合物受体光伏材料,基于这类聚合物受体光伏材料的全聚合物太阳电池的能量转换效率已经超过了15%。最后对共轭聚合物受体光伏材料和全聚合物太阳电池下一步的研究方向和研究重点进行了展望。     

高效钙钛矿太阳电池及其叠层电池研究进展

钙钛矿太阳电池及其叠层电池发展迅速,成为当前光伏领域的研究热点.有机无机卤化钙钛矿材料具有吸收系数高、带隙可调、制备工艺简单等优点,其单结太阳电池实验室效率从2009年的3.8％迅速提升到25.2％,两端钙钛矿/硅叠层太阳电池效率达到29.15％.钙钛矿太阳电池种类丰富,依据器件结构主要分为介孔型钙钛矿太阳电池和平面型(nip结构和pin结构)钙钛矿太阳电池.大量研究工作通过钝化工程、添加剂工程、能级匹配工程、组分工程等先进技术获得高质量的钙钛矿吸收层和光电性能好、低成本、无污染的电荷传输层,提升电荷提取效率,使得每种器件结构均能实现22％以上的超高效率.但常规钙钛矿材料光、湿、热稳定性差,部分研究通过改善吸收层的成分,研发出准二维钙钛矿太阳电池与全无机钙钛矿太阳电池,更加贴合实际应用.考虑到不同的应用场景,钙钛矿太阳电池又进一步分化出柔性钙钛矿太阳电池与半透明钙钛矿太阳电池,透明导电电极的研发成为该领域的重要突破方向.基于钙钛矿的叠层电池中,高效钙钛矿/硅叠层电池是研究重点,通过优化陷光策略和添加剂工程等方法降低光学损失与电学损失,能够在材料成本增长不大的情况下显著提升电池效率,极具市场竞争力.本文主要阐述了钙钛矿太阳电池及其叠层电池的发展历史、器件种类和结构、功能层材料特性、性能优化策略,并对其面临的挑战以及发展趋势进行了总结与展望.     

量子点在低价太阳电池中的应用及研究状况

太阳电池的发展包括3个阶段,已商业化生产的第一代单晶硅电池成本较高,而薄膜化的第二代太阳电池虽大幅降低了成本,但效率不理想。因此,期待比第一代太阳电池有更高转换效率的同时,保持第二代太阳电池低成本优势的第三代太阳电池的诞生。其中,半导体量子点太阳电池因具有高达66%的热力学转换效率备受关注。介绍了基于量子点的几种低价太阳电池,包括全无机纳米结构太阳电池、染料敏化电池及聚合物太阳电池等,重点介绍了由有机聚合物和无机半导体量子点组成的杂化聚合物/量子点电池的结构及影响器件效率的关键因素。     

杂化钙钛矿材料在太阳电池中的应用与发展

杂化钙钛矿是近年来发展非常迅速的一类新型光电材料。自从2009年日本学者首次研究钙钛矿敏化太阳电池, 经过五年的发展, 有机铅卤化物钙钛矿太阳电池光电转换效率从最初的3.1%跃升到19.3%。本文介绍了有机铅卤化物钙钛矿的结构及其在有机/无机杂化钙钛矿太阳电池中的应用, 并从有机铅卤化物钙钛矿太阳电池的发展历程、器件结构、制备方法等方面做了总结。最后简要讨论了钙钛矿太阳电池的长期稳定性、环境问题, 并就未来发展趋势进行展望。     

染料敏化太阳能电池的研究进展

光导电极材料在染料敏化太阳能电池(DSSC)中起到关键作用,直接影响到太阳能电池的总效率,所以一直是DSSC研究的热点.介绍了DSSC的基本工作原理,概述了当前DSSC中最流行的TiO<,2>和ZnO两种薄膜光导电极材料的制备方法,并从结构、工艺和转换效率等方面对染料敏化TiO<,2>薄膜太阳能电池和染料敏化ZnO薄膜太阳能电池进行了介绍和讨论;同时简要介绍了目前研究非常热门的叠层染料敏化太阳电池的研究进程,最后展望了染料敏化太阳能电池的未来发展前景.     

氧化锌纳米棒形貌对ZnO/Cu2O异质结太阳能电池光伏性能的影响

采用电化学沉积法制备了ZnO纳米棒,首先讨论了电化学沉积参数对氧化锌(ZnO)纳米棒形貌的影响,并对不同长度ZnO纳米棒的光吸收和反射等性质进行了研究.实验发现沉积时间是影响纳米棒长度、直径的重要因素,ZnO纳米棒的微观形貌对其光学性质有重要影响.然后以氧化锌纳米棒为n型材料,以氧化亚铜为p型材料,通过电化学沉积法构筑了ZnO/Cu2O异质结太阳能电池,并测试了其光伏性能,研究表明增长纳米棒阵列的长度使得开路电压、短路电流密度及光电转换效率等性能得到提升.最后,综合分析了氧化锌纳米棒形貌与所组装电池的性能之间的关系,发现调控氧化锌纳米棒的形貌是提高ZnO/Cu2O异质结太阳能电池光伏性能的有效途径.     

Electrochemical Deposition of ZnO Nanorods on Transparent Reduced Graphene Oxide Electrodes for Hybrid Solar Cells

Monocrystalline ZnO nanorods (NRs) with high donor concentration are electrochemically deposited on highly conductive reduced graphene oxide (rGO) films on quartz. The film thickness, optical transmittance, sheet resistance, and roughness of rGO films are systematically studied. The obtained ZnO NRs on rGO films are characterized by X‐ray diffraction, transmission electron microscopy, photoluminescence, and Raman spectra. As a proof‐of‐concept application, the obtained ZnO NRs on rGO are used to fabricate inorganic–organic hybrid solar cells with layered structure of quartz/rGO/ZnO NR/poly(3‐hexylthiophene)/poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (P3HT/PEDOT:PSS)/Au. The observed power conversion efficiency (PCE, η), ≈ 0.31%, is higher than that reported in previous solar cells by using graphene films as electrodes. These results clearly demonstrate that rGO films with a higher conductivity have a smaller work function and show a better performance in the fabricated solar cells.     

ZnO纳米四脚状阵列电极染料敏化太阳能电池

采用化学气相沉积(CVD)法制备了不同尺寸的四脚状纳米ZnO和ZnO纳米棒。采用X射线粉末衍射(XRD)、扫描电子显微镜(SEM)对纳米ZnO的晶型结构和形貌进行表征,研究结果表明CVD法制备的四脚状纳米ZnO具有三维空间结构,其最小平均臂宽约为70nm,臂长约300nm,制备的纳米棒直径约为84nm,长约2μm,且都为六方纤锌矿晶型结构。将ZnO纳米四脚状及纳米棒利用滚涂法在FTO导电玻璃上形成ZnO光阳极,经N719染料敏化后组装成染料敏化太阳能电池,光电性能结果表明,染料敏化小尺寸的四脚状纳米ZnO太阳能电池光电转换效率(η=1.88%)高于染料敏化大尺寸的四脚状纳米ZnO太阳能电池光电转换效率(η=1.18%),远高于染料敏化ZnO纳米棒太阳能电池的光电转换效率(η=0.7%)。     

Historical Analysis of High-Efficiency,Large-Area Solar Cells: Toward Upscaling of Perovskite Solar Cells

The status and problems of upscaling research on perovskite solar cells, which must be addressed for commercialization efforts to be successful, are investigated. An 804 cm² perovskite solar module has been reported with 17.9% efficiency, which is significantly lower than the champion perovskite solar cell efficiency of 25.2% reported for a 0.09 cm² aperture area. For the realization of upscaling high-quality perovskite solar cells, the upscaling and development history of conventional silicon, copper indium gallium sulfur/selenide and CdTe solar cells, which are already commercialized with modules of sizes up to ≈25 000 cm², are reviewed. GaAs, organic, dye-sensitized solar cells and perovskite/silicon tandem solar cells are also reviewed. The similarities of the operating mechanisms between the various solar cells and the origin of different development pathway are investigated, and the ideal upscaling direction of perovskite solar cells is subsequently proposed. It is believed that lessons learned from the historical analysis of various solar cells provide a fundamental diagnosis of relative and absolute development status of perovskite solar cells. The unique perspective proposed here can pave the way toward the upscaling of perovskite solar cells.     

Advances in Solution‐Processed Multijunction Organic Solar Cells

The efficiency of organic solar cells can benefit from multijunction device architectures, in which energy losses are substantially reduced. Herein, recent developments in the field of solution‐processed multijunction organic solar cells are described. Recently, various strategies have been investigated and implemented to improve the performance of these devices. Next to developing new materials and processing methods for the photoactive and interconnecting layers, specific layers or stacks are designed to increase light absorption and improve the photocurrent by utilizing optical interference effects. These activities have resulted in power conversion efficiencies that approach those of modern thin film photovoltaic technologies. Multijunction cells require more elaborate and intricate characterization procedures to establish their efficiency correctly and a critical view on the results and new insights in this matter are discussed. Application of multijunction cells in photoelectrochemical water splitting and upscaling toward a commercial technology is briefly addressed.     

Organic Solar Cells: A Review of Materials,Limitations, and Possibilities for Improvement

Significant attention has been given during the last few years to overcome technological and material barriers in order to develop organic photovoltaic devices (OPVs) with comparable cost efficiency similar to the inorganic photovoltaics (PVs) and to make them commercially viable. To take advantage of the low cost for such devices, major improvements are necessary which include: an efficiency of around 10%, high stability from degradation under real-world conditions, novel optically active materials, and development of novel fabrication approaches. In order to meet such stringent requirements, the research and development in OPVs need to improve upon the short diffusion length of excitons, which is one of the factors that are responsible for their low power conversion efficiency. This review discusses some of the most significant technological developments that were presented in the literature and helped improve photovoltaic performance, such as tandem architectures, plasmonics, and use of graphitic nanostructural materials, among others.

Tandem organic solar cells with embedded plasmonics are a promising approach to further increase the power conversion efficiency of organic solar cells, by harvesting complementary spectral regions with high quantum efficiencies. Polymeric nanocomposites incorporating graphitic nanostructures were extensively investigated for the next generation of efficient and low-cost solar cells, since such nanomaterials show excellent electrical and mechanical properties, excellent carrier transport capabilities, and provide an efficient pathway to the dissociated charge carriers.     

Monolithic Organic/Colloidal Quantum Dot Hybrid Tandem Solar Cells via Buffer Engineering

Monolithically integrated hybrid tandem solar cells (TSCs) that combine solution-processed colloidal quantum dot (CQD) and organic molecules are a promising device architecture, able to complement the absorption across the visible to the infrared. However, the performance of organic/CQD hybrid TSCs has not yet surpassed that of single-junction CQD solar cells. Here, a strategic optical structure is devised to overcome the prior performance limit of hybrid TSCs by employing a multibuffer layer and a dual near-infrared (NIR) absorber. In particular, a multibuffer layer is introduced to solve the problem of the CQD solvent penetrating the underlying organic layer. In addition, the matching current of monolithic TSCs is significantly improved to 15.2 mA cm⁻² by using a dual NIR organic absorber that complements the absorption of CQD. The hybrid TSCs reach a power conversion efficiency (PCE) of 13.7%, higher than that of the corresponding individual single-junction cells, representing the highest efficiency reported to date for CQD-based hybrid TSCs.     

Activated Electron‐Transport Layers for Infrared Quantum Dot Optoelectronics

Photovoltaic (PV) materials such as perovskites and silicon are generally unabsorptive at wavelengths longer than 1100 nm, leaving a significant portion of the IR solar spectrum unharvested. Small‐bandgap colloidal quantum dots (CQDs) are a promising platform to offer tandem complementary IR PV solutions. Today, the best performing CQD PVs use zinc oxide (ZnO) as an electron‐transport layer. However, these electrodes require ultraviolet (UV)‐light activation to overcome the low carrier density of ZnO, precluding the realization of CQD tandem photovoltaics. Here, a new sol–gel UV‐free electrode based on Al/Cl hybrid doping of ZnO (CAZO) is developed. Al heterovalent doping provides a strong n‐type character while Cl surface passivation leads to a more favorable band alignment for electron extraction. CAZO CQD IR solar cell devices exhibit, at wavelengths beyond the Si bandgap, an external quantum efficiency of 73%, leading to an additional 0.92% IR power conversion efficiency without UV activation. Conventional ZnO devices, on the other hand, add fewer than 0.01 power points at these operating conditions.     

薄膜太阳能电池的研究进展

综述了目前国际上研究得最多的几种薄膜太阳能电池材料的研究现状和各自的最新进展.包括硅基类(非晶硅、多晶硅、微晶硅)、无机化合物类(碲化镉、铜铟硒、砷化镓)、有机类、染料敏化(二氧化钛、氧化锌)等,并从材料、工艺和转换效率等方面比较和讨论了它们各自性能的优劣,最后展望了这些薄膜太阳能电池材料未来的研究方向及应用前景.