Raman scattering in lead selenide films at a low excitation level

摘要

Raman scattering spectra of epitaxial lead selenide films were measured at low (0.06 mW/mu m(2)) excitation power densities to ensure the absence of photo- and thermal modifications of the film material. It is shown that observed transitions correspond to overtones or combinational tones of PbSe phonon modes implying a high quality of crystalline structure of the material for which the first order Raman effect is prohibited. An increase in incident excitation density leads to the appearance of transitions related to lead oxides, which masks characteristic spectral features of lead selenide.