文献类型：期刊文献

英文题名：Efficient Defect Passivation for Perovskite Solar Cells by Controlling the Electron Density Distribution of Donor-π-Acceptor Molecules

作者：Wu, Tianhao[1];Wang, Yanbo[1];Li, Xing[3];Wu, Yongzhen[3];Meng, Xiangyue[2];Cui, Danyu[1];Yang, Xudong[1];Han, Liyuan[1,2]

机构：[1]Shanghai Jiao Tong Univ, State Key Lab Met Matrix Composites, 800 Dong Chuan Rd, Shanghai 200240, Peoples R China;[2]Natl Inst Mat Sci, Res Network & Facil Serv Div, Tsukuba, Ibaraki 3050047, Japan;[3]East China Univ Sci & Technol, Joint Int Res Lab Precis Chem & Mol Engn, Key Lab Adv Mat, Sch Chem & Mol Engn, Shanghai 200237, Peoples R China

年份：2019

卷号：9

期号：17

外文期刊名：ADVANCED ENERGY MATERIALS

收录：;EI(收录号：20191006605285);WOS:【SCI-EXPANDED(收录号:WOS:000471338400007)】；

基金：T.W. and Y.W. contributed equally to this work. This work was partially supported by the National Natural Science Foundation of China (grant numbers 11574199 and 11674219), the New Energy and Industrial Technology Development Organization (NEDO, Japan), the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning, Natural Science Foundation of Shanghai (17ZR1414800).

语种：英文

外文关键词：defect passivation; donor-pi-acceptor molecules; electron density distribution; perovskite solar cells

摘要：Organic-inorganic hybrid perovskite solar cells (PSCs) are a promising photovoltaic technology that has rapidly developed in recent years. Nevertheless, a large number of ionic defects within perovskite absorber can serve as non-radiative recombination center to limit the performance of PSCs. Here, organic donor--acceptor (D--A) molecules with different electron density distributions are employed to efficiently passivate the defects in the perovskite films. The X-ray photoelectron spectroscopy (XPS) analysis shows that the strong electron donating N,N-dibutylaminophenyl unit in a molecule causes an increase in the electron density of the passivation site that is a carboxylate group, resulting in better binding with the defects of under-coordinated Pb2+ cations. Carrier lifetime in the perovskite films measured by the time-resolved photoluminescence spectrum is also prolonged by an increase in donation ability of the D--A molecules. As a consequence, these benefits contribute to an increase of 80 mV in the open circuit voltage of the devices, enabling a maximum power conversion efficiency (PCE) of 20.43%, in comparison with PCE of 18.52% for the control device. The authors' findings provide a novel strategy for efficient defect passivation in the perovskite solar cells based on controlling the electronic configuration of passivation molecules.