Response of Ch3nh3pbi3 Films to Thermal Exposure and Proton Irradiation

Abstract

For the purpose of the space application, the thermal stability and proton irradiation effects of the MAPbI3 (MA+=CH3NH3+) films have been investigated via the experimental and molecular dynamics simulation methods. Surface decomposition of MAPbI3 is found to occur at 100 ℃, which leads to the formation of a PbI2 layer on the sample surface that suppresses the decomposition of the underlying MAPbI3. PbI2 can be further decomposed into Pb and I2 at 150 ℃, creating a porous structure of the residual MAPbI3 film. After 100 keV proton irradiation, the photoluminescence yield from the MAPbI3 keeps almost unchanged with proton fluences up to 1 × 1013 p/cm2, followed by a rapid decrease at the higher fluences. It is speculated that the irradiation-induced interstitials and vacancies predominantly recombine with each other, which is owing to the fast migration of the defects in MAPbI3. However, the defect recombination efficiency decreases with increasing defect concentration. The MA component in MAPbI3 is preferentially to be damaged by proton irradiation, which accounts for the optical degradation of the film.

Keywords: Perovskites, Proton irradiation, Thermal stability.