Enhanced Power Conversion Efficiency in Bulk Heterojunction Polymer Solar Cells Through Dual-Interface Morphology Modification

Efficient bulk heterojunction（BHJ） polymer solar cells with a poly（3,4-ethylenedioxythiophene）：poly（styrenesulfonate） hole transfer layer（HTL） were fabricated via controlling the spin coating speed of the HTL solution on a particular fluorinated tin oxide substrates of a high roughness.It shows that the functions of the photovoltaic devices increase with the increase of the HTL surface roughness.Then,an imprinting technique was employed to transfer a suitable pattern of nanostructure arrays to the surface of active layers.At the optimized spin coating speed,the photovoltaic devices exhibited a 28.4% increase in efficiency after this imprinting treatment compared with that of nonimprinted photovoltaic devices.It is mainly attributed to the achievement of high interface areas between active layers and electrodes,which not only increases optical absorption by scattering but also facilitates charge carrier collection.

Optimal bulk-heterojunction morphology enabled by fibril network strategy for high-performance organic solar cells

A bicontinuous network formed spontaneously upon film preparation is highly desirable for bulk-heterojunction(BHJ) organic solar cells(OSCs). Many donor-acceptor(D-A) type conjugated polymers can self-assemble into polymer fibrils in the solid state and such fibril-assembly can construct the morphological framework by forming a network structure, inducing the formation of ideal BHJ morphology. Our recent works have revealed that the fibril network strategy(FNS) can control the blend morphology in fullerene, non-fullerene and ternary OSCs. It has been shown that the formation of fibril network can optimize phase separation scale and ensure efficient exciton dissociation and charge carriers transport, thus leading to impressive power conversion efficiencies(PCEs) and high fill factor(FF) values. We believe that FNS will provide a promising approach for the optimization of active layer morphology and the improvement of photovoltaic performance, and further promote the commercialization of OSCs.

Exploring alkylthiol additives in PBDB-T:ITIC blended active layers for solar cell applications

Bulk heterojunction,non-fullerene PBDB-T:ITIC blend polymer solar cells have been fabricated.The active layers consisting of PBDB-T as a donor and ITIC as an acceptor are optimized using a series of alkylthiol additives(1,3-propanedithiol,1,4-butanedithiol,and 1,8-octanedithiol).It is found that the donor and acceptor are phase separated with different crystalline domains.The additives effectively re-organize the morphology and extend the molecule ordering in lamellar structure with increased correlation length in ITIC domain,benefiting the generation and dissociation of exciton and reducing charge recombination.A substantial improvement in power conversion efficiency of the devices from 8.13%to 9.44%is observed.This study shows that the application of alkylthiol additives is a simple and effective approach to improve the device performance in solar cells based on polymer/non-fullerene blend system.

Progress in polymer solar cell

This review outlines current progresses in polymer solar cell. Compared to traditional silicon-based photovoltaic (PV) technology, the completely different principle of optoelectric response in the polymer cell results in a novel configuration of the device and more complicated photovoltaic generation proc-ess. The conception of bulk-heterojunction (BHJ) is introduced and its advantage in terms of mor-phology is addressed. The main aspects including the morphology of photoactive layer, which limit the efficiency and stability of polymer solar cell, are discussed in detail. The solutions to boosting up both the efficiency and stability (lifetime) of the polymer solar cell are highlighted at the end of this review.

体异质结聚合物太阳能电池的界面工程

体异质结聚合物太阳能电池是很有前途的替代化石能源进行能量转换的光伏技术。合成新材料、优化器件结构以及界面工程等方式都能有效提高聚合物太阳能电池的能量转换效率。本文从材料选取、界面掺杂以及界面修饰三个方面阐述界面工程在聚合物太阳能电池中的应用。界面修饰能够促进载流子的产生和输运,证明界面工程对于提高电荷提取效率、钝化表面缺陷和提升电导率等具有重要意义。

体异质结型聚合物太阳电池

聚合物太阳电池因具有重量轻、制备工艺简单、成本低等特点近年来受到了国内外的广泛关注。其中体异质结型聚合物太阳电池(bulk heterojunction polymer solar cell,BHJ-PSC)是目前报道的具有高性能的器件之一。本文系统地综述了BHJ-PSC的最新研究进展。首先介绍了BHJ-PSC的结构及工作原理。其次重点介绍了影响太阳电池性能的给体和受体材料的最新研究成果。另外详细地介绍了影响活性层形貌的几个重要因素,例如共混溶剂和添加剂、给体受体比例以及退火条件等。同时对叠层和反型BHJ-PSC进行了介绍。最后,针对BHJ-PSC存在的问题提出了解决方案并对聚合物太阳电池的应用前景进行了展望。