In‐Situ Growth of One‐Dimensional Blocking Layer to Mitigate Deficient Surface of Single‐Crystal Perovskites
Changke Jiang, Ning Li, Ning Li, Yawei Niu, Nianqiao Liu, Dalin Li, Gan Jin, Yu Lin Zhong, Xutang Tao, Zhaolai Chen
Abstract
Abstract Organic‐inorganic halide perovskite (OIHP) single crystals are promising for optoelectronic application, but their high surface trap density and associated ion migration hinders device performance and stability. Herein, a one‐dimensional (1D) perovskites are designed and proposed as blocking layer at the crystal/electrode interface to mitigate the surface issues. As a model system, the interface ion migration in Cs 0.05 FA 0.95 PbI 3 (FA=formamidinium) single‐crystal perovskite solar cells (PSCs) is obviously suppressed, leading to increase of T 90 lifetime from 260 to 1000 hours, five times better than previously reported results. Besides, the reduction of surface iodide ion vacancies inhibits nonradiative recombination, thus increasing the efficiency from 22.1 % to 23.8 %, which is one of the highest values for single‐crystal PSCs. Since the deficient crystal surface is a universal and open issue, our strategy is instructive for optimizing diverse single‐crystal perovskite devices.