Photoluminescence Properties of Microstructural CH3NH3PbI3 Perovskite Prepared by Thermal Evaporation

Abstract

We report the optical characterizations of perovskite (CH3NH3PbI3) thin films prepared by vapor deposition method By SEM we could observe the difference of crystal size and shape between PbI2 and CH3NH3PbI3 prepared by vapor deposition method The absorbance and transition spectra were investigated to confirm the optical difference between PbI2 and CH3NH3PbI3 Photoluminescence peak of the perovskite films at 780 nm excited via 532 nm CW laser at room temperature was observed and we confirm the bandgap is around 1 58 eV at room temperature through experiments stated above and temperature-dependent PL measurement We also found that high photoluminescence stability of perovskite films prepared by vapor deposition at high relative humidity Last we observed emission peak located at about 780 nm and we change the depths of the films which 532 nm CW laser focuses on to observe PL spectra We found the appearance of two peaks Through XRD patterns we could infer the origins of this feature All measurements except temperature-dependent PL spectra are processed at room temperature and 50% relative humidity This humidity is much higher than other foreign studies Perovskite material has high sensitivity to water molecules so people would prevent perovskite samples from water or high humidity Thus our sample is very strong

Date of Award	2016 Aug 30
Original language	English
Supervisor	Hsu-Cheng Hsu (Supervisor)