Spectroscopy of condensed matter

Features of Raman scattering in lead sulfide and lead sulfide-selenide epitaxial films

A. V. Fedorov^a, A. V. Baranov^a, S. P. Zimin<sup>bc

a</sup> ITMO University, 197101 St. Petersburg, Russia
^b P.G. Demidov Yaroslavl State University, 150003 Yaroslavl, Russia
^c Yaroslavl branch of the Institute of physics and technology, Institution of Russian academy of sciences, 150007 Yaroslavl, Russia

Abstract: Raman scattering spectra of 1–2 $\mu$m thick $n$-PbS(111) epitaxial films grown by molecular beam epitaxy on BaF$_2$(111) substrates were obtained and analyzed. The spectra were recorded at a low excitation level of 0.36 mW/$\mu$m$^2$, which did not cause photo- and thermal degradation of the films. It is shown that, in accordance with the symmetry selection rules, the bands in the spectra correspond to overtone or combination tones of phonon modes of PbS at special points of the Brillouin zone. The analysis of the bands of oxides and oxysulfates of lead, which can mask the bands of lead sulfide, was carried out. The obtained data were used in the analysis of the recorded Raman scattering spectra by epitaxial films of a ternary solid solution PbS$_{0.5}$Se$_{0.5}$.

Keywords: Raman scattering, low excitation level, photooxidation, epitaxial films, lead sulfide, lead sulfide-selenide.

Received: 23.01.2022
Revised: 23.01.2022
Accepted: 07.02.2022

DOI: 10.21883/OS.2022.07.52722.3193-22

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