Jiang Sheng, Xiong Shaobing, Dong Wei, Li Danqin, Yan Yuting, Jia Menghui, Dai Yannan, Zhao Qingbiao, Jiang Kai, Liu Xianjie, Ding Liming, Fahlman Mats, Sun Zhenrong, Bao Qinye
School of Physics and Electronic Science, East China Normal University, Shanghai, 200241, China.
Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai, 200241, China.
Adv Sci (Weinh). 2022 Oct;9(30):e2203681. doi: 10.1002/advs.202203681. Epub 2022 Aug 28.
Perovskite solar cells (PSCs) suffer from significant nonradiative recombination at perovskite/charge transport layer heterojunction, seriously limiting their power conversion efficiencies. Herein, solution-processed chromium multioxide (CrO ) is judiciously selected to construct a MAPbI /CrO /Spiro-OMeTAD hole-selective heterojunction. It is demonstrated that the inserted CrO not only effectively reduces defect sites via redox shuttle at perovskite contact, but also decreases valence band maximum (VBM)-HOMO offset between perovskite and Spiro-OMeTAD. This will diminish thermionic losses for collecting holes and thus promote charge transport across the heterojunction, suppressing both defect-assisted recombination and interface carrier recombination. As a result, a remarkable improvement of 21.21% efficiency with excellent device stability is achieved compared to 18.46% of the control device, which is among the highest efficiencies for polycrystalline MAPbI based n-i-p planar PSCs reported to date. These findings of this work provide new insights into novel charge-selective heterojunctions for further enhancing efficiency and stability of PSCs.
钙钛矿太阳能电池（PSCs）在钙钛矿/电荷传输层异质结处存在显著的非辐射复合，严重限制了其功率转换效率。在此，经过审慎选择，采用溶液处理的二氧化铬（CrO）构建了MAPbI/CrO/Spiro-OMeTAD空穴选择性异质结。结果表明，插入的CrO不仅通过在钙钛矿接触处的氧化还原穿梭有效地减少了缺陷位点，还减小了钙钛矿与Spiro-OMeTAD之间的价带最大值（VBM）-最高占据分子轨道（HOMO）偏移。这将减少收集空穴时的热电子损失，从而促进电荷在异质结中的传输，抑制缺陷辅助复合和界面载流子复合。结果，与对照器件的18.46%相比，实现了21.21%的显著效率提升以及优异的器件稳定性，这是迄今为止报道的基于多晶MAPbI的n-i-p平面PSCs的最高效率之一。这项工作的这些发现为新型电荷选择性异质结提供了新的见解，以进一步提高PSCs的效率和稳定性。
