Paper Title
Photoinduced Defect Formation in Pristine and Doped CsPbBr3 Perovskite

Abstract
The effect of lead substitution by silver cations at concentrations of 0, 0.32, 0.52, 0.97, and 1.53 at% on absorption and photo stimulated defect formation of dispersed CsPbBr3 perovskites has been studied by diffuse reflectance spectroscopy. Our results indicate that Ag+ doping does not affect the band gap in perovskite. The essential response demonstrated by CsPbBr3 perovskites to irradiation in intrinsic absorption spectral region is photo stimulated generation of new defect states. Their formation results in appearance of new corresponding absorption bands in extrinsic absorption spectral region. The analysis of kinetics of photo stimulated defect accumulation infers that two different mechanisms are realized: typical for both photo resistant and photosensitive solids. In former case the photo stimulated defect formation occurs due to charge carrier trapping by existing defects in perovskites while in latter scenario new lattice defect states are formed due to electronic excitation dissipation. It has been demonstrated that efficiencies of both defect formation photo processes are dependent on Ag do pant concentration. Keywords - Halide Perovskites, Doping, Defect Formation, Photo Excitation, Diffuse Reflectance Spectroscopy