Intrinsic photoluminescence Stokes shift in semiconductors demonstrated by thin-film CdS formed with pulsed-laser deposition

Abstract While not reported in the literature, by employing highly oriented, semi-insulating, thin-film CdS as test material, we present the observation of the intrinsic photoluminescence Stokes shift in a semiconductor. Analysis of Raman peaks, transmission, reflection, and photoluminescence shows that during band-to-band emission at room temperature one-to-two longitudinal optical phonons with energy of 39.8 meV are emitted. The result is confirmed by the theoretically expected Huang–Rhys factor.