Electron-phonon interaction in perovskite nanocrystals in fluorophosphate glass matrix

The photoluminescence (PL) spectra of CsPbBr$_3$ perovskite nanocrystals grown in a fluorophosphate glass matrix exhibit phonon replicas of the exciton line. The dependence of intensity of the phonon replica on its number is simulated taking into account the difference in the curvature of the excited and ground adiabatic potentials. The Raman spectra of CsPbBr$_3$ nanocrystals are measured. Calculations based on the density functional theory is performed to obtain the spectrum of phonon states of these crystals in the orthorhombic phase. The phonon frequencies observed in the PL and Raman spectra are compared with the calculation results.