Influence of impurities on the absorption spectrum of thin Cs4PbI6 films

Abstract

The absorption spectrum of the solid solutions (Cs1-xMx)4PbI6 (M=Rb,K) 0х1 is studied in the spectral range 2-6 eV at T = 90K. The formation of solid solutions (Cs1-xRbx)4PbI6 in all range of concentrations is established, the compound К4PbI6 is unstable. Linear concentration of long-wavelength exciton band parameters in the (Cs1-xMx)4PbI6 indicates the localization of excitons in PbI64- structural elements of the compounds crystal lattice