Effect of iodine impurity on the absorption spectrum and phase transitions in CsPbCl3 thin films

Abstract

The absorption spectra of thin films of solid solutions CsPb(Cl1-xIx)3 0<x<1 were studied. It has been found that at low concentrations x<0.2, excitonic spectra of a amalgamation type are formed. The concentration shift of the exciton bands with increasing x at x=0.3 indicates the formation of the exciton spectrum of persistence type in the interval 0.3<x<1. The iodine impurity leads to an insignificant increase of the phase transition temperatures in the orthorhombic and cubic phases of CsPbCl3.