We present a combined experimental and computational study of two-dimensional molybdenum disulfde (MoS2) and the effect of temperature on the frequency shifts of the Raman-active E2g and A1g modes in the monolayer. While both peaks show an expected red-shift with increasing temperature, the frequency shift is larger for the A1g more than for the E2g mode. This is in contrast to previously reported bulk behavior, in which the E2g mode shows a larger frequency shift with temperature. The temperature dependence of these phonon shifts is attributed to the anharmonic contributions to the ionic interaction potential in the two-dimensional system.
@article{arxiv.1307.2447,
title = {Temperature-dependent Phonon Shifts in Monolayer MoS2},
author = {Nicholas Lanzillo and A. Glen Birdwell and Matin Amani and Frank J. Crowne and Pankaj B. Shah and Sina Najmaei and Zheng Liu and Pulickel M. Ajayan and Jun Lou and Madan Dubey and Saroj K. Nayak and Terrance P. O'Regan},
journal= {arXiv preprint arXiv:1307.2447},
year = {2015}
}