Resolving Mixed Intermediate Phases in Methylammonium-Free Sn-Pb Alloyed Perovskites for High-Performance Solar Cells  

作　　者：Zhanfei Zhang Jianghu Liang Jianli Wang Yiting Zheng Xueyun Wu Congcong Tian Anxin Sun Zhenhua Chen Chun-Chao Chen 

机构地区：[1]School of Materials Science and Engineering,Shanghai Jiao Tong University,Shanghai 20024,People’s Republic of China [2]Shanghai Synchrotron Radiation Facility(SSRF),Shanghai Advanced Research Institute,Chinese Academy of Sciences,Shanghai 201800,People’s Republic of China

出　　处：《Nano-Micro Letters》2022年第10期178-196,共19页纳微快报（英文版）

基　　金：funded by the Natural Science Foundation of Shanghai(22ZR1428200);the National Natural Science Foundation of China(51950410581);the Shanghai Government(20JC141500);and CATL-SJTU joint funding.

摘　　要：The complete elimination of methylammonium(MA)cations in Sn-Pb composites can extend their light and thermal stabilities.Unfortunately,MA-free Sn-Pb alloyed perovskite thin films suffer from wrinkled surfaces and poor crystallization,due to the coexistence of mixed intermediate phases.Here,we report an additive strategy for finely regulating the impurities in the intermediate phase of Cs_(0.25)FA_(0.75)Pb_(0.6)Sn_(0.4)I_(3)and,thereby,obtaining high-performance solar cells.We introduced d-homoserine lactone hydrochloride(D-HLH)to form hydrogen bonds and strong Pb-O/Sn-O bonds with perovskite precursors,thereby weakening the incomplete complexation effect between polar aprotic solvents(e.g.,DMSO)and organic(FAI)or inorganic(CsI,PbI_(2),and SnI_(2))components,and balancing their nucleation processes.This treatment completely transformed mixed intermediate phases into pure preformed perovskite nuclei prior to thermal anneal-ing.Besides,this D-HLH substantially inhibited the oxidation of Sn^(2+) species.This strategy generated a record efficiency of 21.61%,with a Voc of 0.88 V for an MA-free Sn-Pb device,and an efficiency of 23.82%for its tandem device.The unencapsulated devices displayed impressive thermal stability at 85℃ for 300 h and much improved continuous operation stability at MPP for 120 h.

关 键 词：Intermediate phase Homogeneous nucleation process MA-free tin-lead alloyed perovskite Light and thermal stability Tandem device 

分 类 号：TM914.4[电气工程—电力电子与电力传动]