Thermally induced correlation effects studied by Raman spectroscopy in PtSe2/Al2O3 systems

Abstract

In this paper, we report the analysis of the Raman spectroscopy results of PtSe₂ layers (ranging from 1 to 10 layers) deposited on an Al₂O₃ substrate, compared to those of the sub-micron thin flake and bulk PtSe₂. The positions of typical PtSe₂ Raman modes and the integral intensity ratios of the A_1g and E_1g bands are compared and discussed for all the systems considered in the temperature range from room temperature to 520 K. Moreover, the correlation plot of E_1g and A_1g is used to analyse the correlations of the dominant Raman modes in the PtSe₂/Al₂O₃ systems, in which the frequency position (in-plane to out-of-plane) ratio exhibits a well-defined linear dependence on temperature.