The Evolution of Photoluminescence Properties of PEA<sub>2</sub>SnI<sub>4</sub> Upon Oxygen Exposure: Insight into Concentration Effects
Yangyang Ju, Xian‐gang Wu, Sheng Huang, Guang Dai, Tinglu Song, Haizheng Zhong
Abstract
Abstract The time evolution of the photoluminescence properties in phenylethylammonium tin halide perovskite (PEA 2 SnI 4 ) film as a function of oxygen concentration is reported. Photo‐brightening and reversible photoluminescence quenching are observed in PEA 2 SnI 4 film at ultralow oxygen concentration (< 1.5 vol%). In the case of 1.5 vol% < [O 2 ] < 21 vol%, the photoluminescence emission of PEA 2 SnI 4 film can be partially recovered after resetting the samples to nitrogen box. As the oxygen concentration further increases with the range of 21 to 95 vol%, the photoluminescence emission of PEA 2 SnI 4 film is significantly quenched and can only be slightly recovered after removing it to the nitrogen box. By correlating the material characterizations and theoretical analysis, the interactions between PEA 2 SnI 4 and oxygen contain physisorption and chemical reactions are illustrated. Depending on the oxygen concentration, the chemical reactions between PEA 2 SnI 4 and oxygen can be reversible and/or irreversible. The insights into oxygen concentration effects provide a guideline to optimize the stability of PEA 2 SnI 4 for achieving high‐performance optoelectronic devices.