The integration structure enhances performance of perovskite solar cells

• 作者: Qiang Zeng Xianyi Meng Zhimin Fang Ming Cheng Shangfeng Yang Yongbo Yuan Yuanhang Cheng Zhiwen Jin Qinye Bao Fangyang Liu Feng Hao Liming Ding
• 来源期刊: 科学通报（英文版）
• 年，卷（期）: 2021,（4）
• 所属期刊栏目: SHORT COMMUNICATIONS
• 页码范围: 310-313
• 页数: 4页
• 语种: 英文

摘要

In recent years, all-inorganic perovskite solar cells (PSCs) have attracted tremendous interest due to their excellent thermal stability [1-3].Unlike organic-inorganic halide perovskites, whose organic component is volatile at temperatures higher than 200 ℃, all-inorganic perovskites can tolerate temperatures over 400 ℃ without deterioration [4].However, the power conversion efficiency (PCE) for all-inorganic PSCs is much lower than that of organic-inorganic halide PSCs mainly due to its Wider bandgap,which leads to limited light absorption and low short-circuit current density (Jsc).At present, the most studied all-inorganic perovskites are CsPbI3 and CsPbl2Br.Partly replacing Ⅰ with Br can decrease the preparation temperature, but the bandgap will increase [5,6].To improve the performance of inorganic PSCs,many researches focused on crystallinity control and interfacial engineering [7-10].Few works were done to broaden the photoresponse to improve Jsc, thus improving the PCE.Developing tandem or integrated solar cells is an effective approach to make full use of sunlight [11,12].For tandem solar cells, the preparation process is very complicated.As for integrated devices, direct deposition of solution-processed organic bulk-heterojunction (BHJ) layer on perovskite layer makes preparation process easier.And the BHJ layer not only acts as charge-transport layer (CTL), but also absorbslow-energy photons to increase the Jsc.However, the utilization of BHJ as CTL makes integrated solar cells suffer from open circuit voltage (Voc) loss.Therefore, in this work, we applied our original concept of integrated solar cells by just using a polymer donor PTB7-Th (Fig.1a) rather than BHJ.PTB7-Th not only acts as the hole-transport layer (HTL) in CsPbI2Br solar cells but also broadens the photoresponse.Moreover, PTB7-Th can also passivate the CsPbl2Br surface and suppress the charge recombination at the interface.The best device based on PTB7-Th HTL offered a PCE of 14.63％.