Identification of the symmetry of phonon modes in CsPbCl3 in phase IV by Raman and resonance-Raman scattering

The first- and second-order Raman phonon spectra of CsPbCl3 were measured in phase IV using Raman and resonance-Raman scattering. Twelve Raman active phonons were resolved at 32, 35.5, 42, 52, 72, 90, 110, 115, 121, 189, 200.5, and 375 cm−1 and correlated to the phonon spectrum of CsPbCl3 in phase I. The highest frequency longitudinal optical mode is 375 cm−1.