Raman spectroscopy of layered lead tin disulfide (PbSnS2) thin films

Nowadays, the attention of researchers is focused on the large family of chalcogenides that poses very unique and interesting properties. One of them is the teallite – PbSnS 2 , almost unrevealed ternary compound, promising thermoelectric material. In this work, we present first detailed Raman studies of PbSnS 2 , including the polarization‐dependent and temperature‐dependent measurements (80–400 K range). The strong effect of polarization angle and temperature on the Raman spectra was observed. The polarization studies allowed to assign symmetry of observed modes. The temperature evolutions of the Raman spectra were explained by optical phonon decay into two or three acoustic phonons with equal energies. The extracted first‐order temperature coefficients are among the largest reported so far for layered materials. Our results might be helpful in understanding the anisotropic optical, thermal and electrical properties of PbSnS 2 . Copyright © 2016 John Wiley & Sons, Ltd.