Study of the Substrate-Induced Strain of As-Grown Graphene on Cu(100) Using Temperature-Dependent Raman Spectroscopy: Estimating the Mode Grüneisen Parameter with Temperature

Abstract

The strategy of using the thermal expansion of copper single crystal can provide an approach of homogenous strain along the basal plane to study the strain characteristic of graphene with temperature. Using an in-situ Raman measurement under a ultra-high vacuum (UHV) environment, the ability to remove contaminations allowed the direct observation of the strain property in as-grown chemical vapor deposition (CVD)-graphene with temperature on a Cu(100) substrate. In this study, the strain coefficients of G and G’ band with temperature were investigated from the in-situ temperature-dependent Raman spectra of the as-grown CVD-graphene on the single crystal of Cu(100) under UHV. By eliminating the minor contributions of the lattice expansion and anharmonic phonon scattering effects, we were able to estimate the strain coefficient of the G and G’ bands of graphene over a wide temperature from 100 K to 800 K. Based on the strain coefficients and the correlation map of the G- and G’-band frequencies, we made a re...