Gu Xiaojing, Xiang Wanchun, Tian Qingwen, Liu Shengzhong Frank
Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Shaanxi Key Laboratory for Advanced Energy Devices, Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi'an, 710119, China.
Dalian National Laboratory for Clean Energy;, iChEM, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.
Angew Chem Int Ed Engl. 2021 Oct 18;60(43):23164-23170. doi: 10.1002/anie.202109724. Epub 2021 Sep 15.
Iodine vacancies (V ) and undercoordinated Pb on the surface of all-inorganic perovskite films are mainly responsible for nonradiative charge recombination. An environmentally benign material, histamine (HA), is used to passivate the V in perovskite films. A theoretical study shows that HA bonds to the V on the surface of the perovskite film via a Lewis base-acid interaction; an additional hydrogen bond (H-bond) strengthens such interaction owing to the favorable molecular configuration of HA. Undercoordinated Pb and Pb clusters are passivated, leading to significantly reduced surface trap density and prolonged charge lifetime within the perovskite films. HA passivation also induces an upward shift of the energy band edge of the perovskite layer, facilitating interfacial hole transfer. The combination of the above raises the solar cell efficiency from 19.5 to 20.8 % under 100 mW cm illumination, the highest efficiency so far for inorganic metal halide perovskite solar cells (PSCs).
全无机钙钛矿薄膜表面的碘空位（V ）和配位不足的Pb是无辐射电荷复合的主要原因。一种环境友好型材料——组胺（HA），被用于钝化钙钛矿薄膜中的V 。一项理论研究表明，HA通过路易斯酸碱相互作用与钙钛矿薄膜表面的V 结合；由于HA有利的分子构型，额外的氢键（H键）增强了这种相互作用。配位不足的Pb和Pb簇被钝化，导致钙钛矿薄膜内的表面陷阱密度显著降低，电荷寿命延长。HA钝化还会引起钙钛矿层能带边缘的向上移动，促进界面空穴转移。上述因素的综合作用使太阳能电池在100 mW cm光照下的效率从19.5%提高到20.8%，这是目前无机金属卤化物钙钛矿太阳能电池（PSC）的最高效率。
