title: Surface passivation of mixed-halide perovskite CsPb(BrxI1-x)3nanocrystals by selective etching for improved stability.
abstract: In recent years, there has been an unprecedented rise in the research of halide perovskites because of their important optoelectronic applications, including photovoltaic cells, light-emitting diodes, photodetectors and lasers. The most pressing question concerns the stability of these materials. Here faster degradation and PL quenching are observed at higher iodine content for mixed-halide perovskite CsPb(BrxI1-x)3nanocrystals, and a simple yet effective method is reported to significantly enhance their stability. After selective etching with acetone, surface iodine is partially etched away to form a bromine-rich surface passivation layer on mixed-halide perovskite nanocrystals. This passivation layer remarkably stabilizes the nanocrystals, making their PL intensity improved by almost three orders of magnitude. It is expected that a similar passivation layer can also be applied to various other kinds of perovskite materials with poor stability issues.
authors.affiliation: National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Jing
authors.forename: Mian
authors.initials: M
authors.lastname: Zhang
authors.forename: Xiang
authors.initials: X
authors.lastname: Huang
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Ren
authors.forename: Peng
authors.initials: P
authors.lastname: Wang
authors.forename: Zhenda
authors.initials: Z
authors.lastname: Lu