Enhancing the Efficiency and Stability of Triple-Cation Perovskite Solar Cells by Eliminating Excess PbI2 from the Perovskite/Hole Transport Layer Interface

• DOI: 10.1021/acsami.0c17258
• Publication Date: 2020-11-23T23:44:57Z
• Authors: Zhelu Hu; Qingzhi An; Hengyang Xiang; Lionel Aigouy; Baoquan Sun; Yana Vaynzof; Zhuoying Chen
• Keywords: Formamidinium; Perovskite solar cell

Metal halide perovskites are promising contenders for next-generation photovoltaic applications due to their remarkable efficiency and compatibility with solution-processed fabrication. Among the various strategies control crystallinity morphology of perovskite active layer its interfaces transport layers, fabrication solar cells from precursor solutions a slight excess PbI2 has become very common. Despite this, role such is still rather controversial, lacking consensus on effect bulk interface properties layer. In this work, we investigate removing surface triple-cation mixed-halide Cs0.05(FA0.83MA0.17)0.95Pb(I0.83Br0.17)3 by four different organic salts performance stability. We show that treatments iodide as methylammonium (MAI) formamidinium (FAI) can lead strongest beneficial effects cell efficiency, charge recombination suppression, stability while non-iodide bromide (MABr) chloride (MACl) also provide improvement in terms suppression moderate extent comparison untreated sample. Under optimized conditions continuous illumination, MAI- FAI-treated devices maintained 81 86% initial power conversion (PCEs), respectively, after 100 h illumination (versus 64% PbI2). Our study demonstrates eliminating at perovskite/hole (HTL) treating simple efficient route enhance particular cells.