Assessment of the anharmonic phonon decay, Fröhlich interactions, and phonon lifetime in Zn0.98Mn0.02S thin films through temperature‐dependent Raman spectroscopy

Abstract This report accounts for the occurrence of the temperature‐induced variation in the phonon properties and the spatial variation in the Raman spectra for the spray‐deposited Zn 0.98 Mn 0.02 S thin films. The study of the temperature dependence of the Raman line position, line width, and the phonon lifetime using the theoretical models that consider the thermal expansion and three‐ and four‐phonon anharmonic effects is the novelty of this work. The lifetime of the LO phonon in Zn 0.98 Mn 0.02 S thin film was as low as 0.234 ps, indicating material suitability for optical limiting applications. The intensity ratio I 2LO /I 1LO ranges within 0.5 at most of the ( x , y ) positions in the Raman mapping data, indicating the nanocrystalline nature of Zn 0.98 Mn 0.02 S.