体相异质结型有机太阳能电池的研究进展

基于电子给/受体共混体系制备的体相异质结型有机太阳能电池是一种低耗、高效的有机光伏器件.作为器件核心,光电转化共混活性层的质量优劣会直接影响器件的能量转换效率.研究发现,不同的给/受体材料组成、2种材料的共混比例、共溶剂的选择以及器件的热退火处理等因素都可影响到活性层质量.结合上述研究热点,综述了体相异质结型有机太阳能电池近年来的研究进展,阐述了该研究领域下一步发展的重点、趋势及前景.     

Si/PEDOT:PSS异质结太阳能电池研究进展

以有机材料作为空穴传输层的Si/有机杂化太阳能电池由于其器件结构与制备工艺的不断优化,在短期内实现了理论探究与合成应用的快速增长。但有机材料具有的导电性低和复合界面间稳定性差等缺点,严重影响了复合器件的光电转化效率和使用寿命,阻碍了异质结太阳能电池的技术发展与市场应用。在Si/有机杂化太阳能电池领域,聚3,4-乙烯二氧噻吩/聚苯乙烯磺酸盐(PEDOT∶PSS)是目前为止效果最佳的有机半导体。PEDOT∶PSS具有高导电性和高透过率等特点,使其成为一种理想的有机空穴传输层材料,并在异质结太阳能电池技术发展和工业应用中脱颖而出。利用PEDOT∶PSS的高导电性能可实现空穴的有效传输,其较高的透过性降低了P-N结生成过程中的寄生吸收,并且在制备中免去了传统硅基太阳能电池所需的高温环节,有效地降低了实际生产成本。近五年来,为降低PEDOT∶PSS中绝缘的PSS对电子传输和表面复合性的影响,大量学者进行了掺杂改性和界面设计的研究工作,有效降低了绝缘性PSS带来的影响,充分发挥了PEDOT高透性和高导电率的优势,优化表面陷光性和器件稳定性,实现了光电转化效率从5.09%至17.4%的大幅度跳跃。本文从Si/PEDOT∶PSS异质结太阳能电池的结构与工作原理出发,重点介绍了Si材料和PEDOT∶PSS有机物的表面修饰、PEDOT∶PSS的掺杂改性、界面氧化层改性和对嵌入式微电网电极改造手段及它们对整体器件性能提升的影响等工作,归纳并分析了Si/PEDOT∶PSS杂化太阳能电池的最新研究进展,展望了太阳能电池的技术研发和理论研究,对未来Si/PEDOT∶PSS异质结太阳能电池的实验室技术研发与工业化生产应用具有一定参考意义。     

CuSCN作为石墨烯/硅异质结太阳能电池无机界面层的数值模拟

界面工程是改善石墨烯/硅异质结太阳能电池性能的有效方法之一,但目前常用的界面材料存在价格高、稳定性差等问题.本实验采用AFORS-HET软件对石墨烯/硅太阳能电池进行数值模拟,并引入无机界面材料CuSCN实现降低电池成本、优化器件性能和稳定性的目的,研究了CuSCN界面层的作用、CuSCN层的空穴迁移率和CuSCN/n-Si的价带补偿对太阳能电池性能的影响.结果表明,引入CuSCN界面层和增加CuSCN层的空穴迁移率均有利于提高器件的光伏性能.当CuSCN/n-Si界面的价带补偿大于-0.1 eV时,CuSCN层可作为电子阻挡-空穴传输层;并且当CuSCN/n-Si界面的价带补偿为0.2 eV时,所构建的石墨烯/CuSCN/硅异质结太阳能电池模型取得了25.8％的最佳光电转换效率.本研究有助于揭示影响石墨烯/CuSCN/硅异质结太阳能电池性能的各种因素,为制备低成本、高效率的石墨烯/硅太阳能电池提供了有效途径.     

硅异质结太阳能电池用透明导电氧化物薄膜的研究现状及发展趋势

硅异质结(SHJ)太阳能电池是目前光伏产业中的重要组成部分,其由于具有高开路电压(V_oc)等优点而引起了广泛的关注。在硅异质结太阳能电池中,透明导电氧化物(TCO)薄膜层的光学性能和电学性能分别影响着电池的短路电流(J_sc)、填充因子(FF),进而影响电池的转换效率。近年来,SHJ电池中TCO层的研究主要集中于掺杂的In₂O₃和ZnO体系。本文从硅异质结太阳能电池的不同结构出发,概述了TCO薄膜的光电性能(透过率、禁带宽度、方块电阻、载流子浓度、迁移率和功函数)以及与相邻层的接触对电池性能的影响,介绍了不同体系的透明导电氧化物薄膜在硅异质结太阳能电池中的应用及研究现状,并展望其未来的发展趋势。     

聚噻吩/无机纳米异质结薄膜太阳能电池材料的研究进展

近年来基于聚噻吩/无机纳米材料的异质结薄膜太阳能电池研究发展迅速,引起了研究者广泛的关注。阐述了异质结薄膜太阳能电池的工作原理,较全面综述了聚噻吩/无机纳米材料的异质结薄膜太阳能电池的最新研究结果,包括:聚噻吩与TiO2、ZnO、CdSe和CdS无机纳米材料复合电池器件等。分析和展望了今后聚噻吩/无机纳米材料异质结薄膜太阳能电池的研究重点和发展方向。     

(PEDOT-PSS)-碳纳米管复合膜硅基太阳能电池

碳纳米管-Si(CNTs-Si)肖特基太阳能电池具有制作简单、成本低的优势。然而,受限于CNTs薄膜的电阻高、结区均匀性差、反光严重等因素,该类器件的光电转换效率仍较低。本文研究了聚3,4-乙撑二氧噻吩-聚苯乙烯磺酸盐(PEDOT-PSS)-CNTs复合透明膜的制备及其在硅太阳能电池中的应用。电流-电压曲线表明,PEDOT-PSS的引入可以大幅度提升CNTs-Si器件的光电转换效率(从5.9%到11.6%)。作为透明电极,复合膜中的取向CNTs可有效地收集和传导太阳能电池结区的光生空穴,而PEDOT-PSS则有效填补了CNTs膜的面内空隙,进而增加了肖特基结的面积。采用表面刻有倒金字塔结构的聚二甲基硅氧烷(PDMS)作为减反层,有效地降低入射光的反射,增加Si表面对光的吸收,进一步将(PEDOT-PSS)-CNTs-Si器件的光电转换效率提升至12.4%。电子束感生电流技术表明器件的光电转换主要基于复合膜与Si之间的肖特基结。     

纳米与粉体材料

金纳米层可改善太阳能电池转换效率据报道,美国加州大学洛杉矶分校的研究人员与来自中国和日本的同行通过将金纳米粒子用于有机光电太阳能电池,助其增强了光吸收的能力,极大地提高了电池的光电转化率。在太阳能的世界,有机光电太阳能电池具有广泛的潜在应用,不过它们至今仍被认为是处于起步阶段。这些用有机高分子或小分子作为半导体的碳基电池     

新型钙钛矿太阳能电池的研究进展

太阳能光伏发电是解决目前日益严重的能源与环境问题的一种有效手段,在最近几年里,新型钙钛矿太阳能电池得到迅猛发展,其最高光电转换效率已经达到20%,已成为可再生能源领域的研究热点之一。钙钛矿太阳能电池是以具有钙钛矿结构的有机-金属卤化物等作为核心光吸收、光电转换、光生载流子输运材料的太阳能电池,具有能量转换高和成本低的优点且其核心光电转换材料具有廉价、容易制备的特点,因此获得了学术界的特别关注。首先总结了钙钛矿太阳能电池的结构与原理,然后综述了钙钛矿太阳电池在结构和材料方面的最新研究进展,特别是无铅钙钛矿太阳能电池的一些研究,最后分析了钙钛矿太阳能电池的发展趋势及发展中亟需解决的问题。     

氧化钼空穴传输层在有机太阳能电池中的研究进展

有机太阳能电池是一类具有前途的解决能源和环境问题的太阳能电池。其中有机太阳能电池中的空穴传输层对器件性能起着重要的作用。氧化钼因无毒、高功函等优点,在有机太阳能电池中作为空穴传输层得到了广泛的应用研究。从氧化钼的制备和器件结构方面综述了氧化钼在有机太阳能的研究成果,初步展望了其以后的发展方向。     

有机太阳能电池电子传输层材料研究进展

随着人类社会的不断进步和科学技术的迅猛发展,太阳能作为一种可再生能源在如今资源匮乏的年代备受关注。太阳能具有成本低廉、储量丰厚、利用简单等诸多优点,吸引了众多学者竞相研究探索。有机太阳能电池作为新一代固态薄膜电池,因其可溶液加工、卷对卷印刷和打印制备成柔性器件,向已经商业化但价格昂贵的无机硅太阳能电池发起了革命性的挑战。在现阶段,有机太阳能电池还存在稳定性相对较弱和光电转换效率相对偏低两方面的缺陷。尽管已报道的有机太阳能电池的光电转换效率已经达到16.70%,但离商业化生产还有很大距离。电子传输层在器件中发挥着重要的作用,对有机太阳能电池的光电转换效率和稳定性有重要影响。目前,应用于有机太阳能电池的电子传输层材料主要为金属氟化物、n型金属氧化物、有机小分子类、聚合物电解质类和富勒烯类等。在众多电子传输层材料中,有机类电子传输层因其结构可调、可溶液加工、便于大面积印刷等优势而备受关注。本文对有机类电子传输层材料进行了归纳总结,包含聚芴类、聚噻吩类、苝酰亚胺类、富勒烯类。通过阐述已有的研究进展,对比分析各种电子传输层材料的优劣,展望电子传输层材料的发展趋势和研究前景。     

Solution-processed bulk heterojunction solar cells based on interpenetrating CdS nanowires and carbon nanotubes

Incorporation of a bulk heterojunction is an effective strategy to enhance charge separation and carrier transport in solar cells, and has been adopted in polymeric and colloidal nanoparticle solar cells to improve energy conversion efficiency. Here, we report bulk heterojunction solar cells based on one-dimensional structures, fabricated by mixing CdS nanowires (CdS NWs) and single-walled carbon nanotubes (CNTs) to form a composite film with mutually interpenetrating networks through a simple solution-filtration process. Within the composite, the CNT network boosts charge separation by extracting holes generated from CdS NWs and also forms the transport path for carrier collection by the external electrode. At an optimized CNT loading of about 5 wt.%, the CdS NW/CNT bulk heterojunction solar cells showed three orders of magnitude increase in photocurrent and cell efficiency compared to a cell with the same materials arranged in a stacked layer configuration with a plain heterojunction. External quantum efficiency and photoluminescence studies revealed the efficient charge transfer process from photoexcited CdS NWs to CNTs in the mixed form. Our results indicate that the bulk heterojunction structure strategy can be extended to semiconductor NWs and CNTs and can greatly improve solar cell performance.      

Effect of perylenetetracarboxylic dianhydride layer as a hole blocking layer on photovoltaic performance of poly-vinylcarbazole: C60 bulk heterojunction thin films

Thin film solar cells with a structure of poly(9-vinylcarbazole) and C₆₀ bulk heterojunction were fabricated and characterized. The effects of 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) as a hole blocking layer for the organic solar cells between active layer and metal layer were also investigated, and the optimized cell structures with PTCDA improved the short-circuit current density and fill factor up to twice values, which resulted in an increase of the conversion efficiency. Microstructure analysis was carried out by using X-ray diffraction and transmission electron microscopy, which indicated the bulk nanocomposite structure Energy levels of the molecules were calculated, and the interfacial structure was discussed based on the experimental and calculated results.     

Three-dimensional nano-networked P3MT/PCBM solar cells

The bulk heterojunction has been widely applied for the construction of efficient organic polymer solar cells. Typically, the heterojunction is formed as a result of the phase segregation of the donor and acceptor mixture. Here, we report a study in which, differently than the common annealing approach, efficient bulk heterojunction solar cells were fabricated using electrochemically grown 3-dimension (3D) poly-3-methyl-thiophene (P3MT) nano-networked structures. Porous and interconnected P3MT (donor) nano-structures were first electrochemically grown on a transparent Au electrode; then PCBM (acceptor) was infiltrated into the openings of the 3D P3MT nano-structure structure to form the bulk heterojunction. With this approach, efficient exciton dissociation can be realized, and importantly, excellent continuity of both donor and acceptor phases can be accomplished; and proper connection of each phase to the corresponding electrode is insured, therefore allowing effective collection of the free carriers. A power conversion efficiency (PCE) of 3.0% has been demonstrated.     

无机纳米晶/共轭聚合物太阳能电池光敏层制备方法及微观形貌调控

相比硅太阳能电池,无机纳米晶/共轭聚合物太阳能电池因其兼备有机/无机杂化的优点,而近年来一直是国内外广泛关注的热点之一.文中对目前该种太阳能电池光敏层的各种微观形貌、制备方法及研究进展进行了综述.详细介绍了无机纳米晶/共轭聚合物光敏层的三种制备方法,即物理共混法、化学键合式共混法和原位法.同时着重关注了无机纳米晶/共轭...     

影响共混结构聚合物光电池性能的因素

共混结构聚合物光电池是一种极有前途的太阳能电池, 其性能主要由器件的开路电压Voc,短路电流Isc,填充因子FF,能量转换效率η等因素决定.笔者结合自己的实验经验,从溶剂、给体与受体材料的比例、器件后处理、电极等方面综述了这些因素对器件的性能影响,为提高聚合物光电池工艺提供了有意义的信息.     

Mechanism of recombination losses in bulk heterojunction P3HT:PCBM solar cells studied using intensity modulated photocurrent spectroscopy

Intensity modulated photocurrent (IMPS) and photovoltage (IMVS) spectroscopies were used to study the mechanism of photoprocesses in P3HT:PCBM bulk heterojunction organic solar cells at various light intensities. The use of the frequency domain techniques allowed us to separate the bulk and interfacial processes and gain a valuable insight into the mechanism of losses in these devices. The results provide direct evidence that interfacial nongeminate recombination is one of the dominant loss and aging mechanisms in bulk heterojunction organic solar cells. The trapping of photoexcited holes in the P3HT phase was found to contribute to the increased recombination rate. The results suggest that promising ways of improving the efficiency of bulk heterojunction solar cells may be reducing the charge trapping both at and near the P3HT:PCBM interface, as well as improving the efficiency of charge extraction at contacts.     

Printing highly efficient organic solar cells

The technological attraction in organic solar cells is their compatibility to printing processes. However, up to today, nearly no literature on "printed" organic solar cells have been published and the major body of the research work was done by spin coating or blading techniques. Transferring the spin-coating or doctor blading process currently used for the fabrication of bulk heterojunction solar cell to a printing process holds morphological challenges that have not been observed or reported up to today. We highlight these challenges and we show that inkjet printing of organic bulk heterojunction solar cells requires completely novel approaches and skill sets compared to the current state of the art. By adjusting the chemical properties of the poly(3-hexylthiophene) polymer donor and by using our recently developed inkjet solvent mixture, we have gained control over the nanomorphology of poly(3-hexylthiophene):fullerene blends during the printing process and report a new record power conversion efficiency of 3.5% for inkjet printed poly(3-hexylthiophene):fullerene based solar cells.     

Controlled growth of a molecular bulk heterojunction photovoltaic cell.

The power conversion efficiency of organic photovoltaic cells has increased with the introduction of the donor-acceptor heterojunction that serves to dissociate strongly bound photogenerated excitons. Further efficiency increases have been achieved in both polymer and small-molecular-mass organic photovoltaic cells through the use of the bulk heterojunction (BHJ), where the distance an exciton must diffuse from its generation to its dissociation site is reduced in an interpenetrating network of the donor and acceptor materials. However, the random distribution of donor and acceptor materials in such structures can lead to charge trapping at bottlenecks and cul-de-sacs in the conducting pathways to the electrodes. Here, we present a method for growing crystalline organic films into a controlled bulk heterojunction; that is, the positions and orientations of donor and acceptor materials are determined during growth by organic vapour-phase deposition (OVPD), eliminating contorted and resistive conducting pathways while maximizing the interface area. This results in a substantial increase in power conversion efficiency compared with the best values obtained by 'random' small-molecular-weight BHJ solar cells formed by high-temperature annealing, or planar double heterojunction photovoltaic cells using the same archetypal materials systems.     

High‐Performance Organic Bulk‐Heterojunction Solar Cells Based on Multiple‐Donor or Multiple‐Acceptor Components

Organic solar cells (OSCs) based on bulk heterojunction structures are promising candidates for next‐generation solar cells. However, the narrow absorption bandwidth of organic semiconductors is a critical issue resulting in insufficient usage of the energy from the solar spectrum, and as a result, it hinders performance. Devices based on multiple‐donor or multiple‐acceptor components with complementary absorption spectra provide a solution to address this issue. OSCs based on multiple‐donor or multiple‐acceptor systems have achieved power conversion efficiencies over 12%. Moreover, the introduction of an additional component can further facilitate charge transfer and reduce charge recombination through cascade energy structure and optimized morphology. This progress report provides an overview of the recent progress in OSCs based on multiple‐donor (polymer/polymer, polymer/dye, and polymer/small molecule) or multiple‐acceptor (fullerene/fullerene, fullerene/nonfullerene, and nonfullerene/nonfullerene) components.     

P3HT:PCBM, best seller in polymer photovoltaic research

In the field of polymer‐based photovoltaic cells, poly(3‐hexylthiophene) (P3HT) and 1‐(3‐methoxycarbonyl)propyl‐1‐phenyl[6,6]C₆₁ (PCBM) are, to date, the most‐studied active materials around the world for the bulk‐heterojunction structure. Various power‐conversion efficiencies are reported up to approximately 5%. This Research News article is focused on a survey of the tremendous literature published between 2002 and 2010 that exhibits solar cells based on blends of P3HT and PCBM.