▎ 摘　　要

The strategy of using the thermal expansion of a copper single crystal can provide an approach to produce homogeneous strain along the basal plane to study the strain characteristic of graphene with temperature. Using an in situ Raman measurement under an ultrahigh vacuum (UHV) environment, the ability to remove contaminations allowed the direct observation of the strain property in as-grown chemical vapor deposited graphene (CVD-graphene) with temperature on a Cu(100) substrate. In this study, the strain coefficients of the G and G' bands with temperature were investigated from the in situ temperature-dependent Raman spectra of the as grown CVD-graphene on the Cu(100) single crystal 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 range from 100 to 800 K. On the basis of the strain coefficients and the correlation map of the G- and G'-band frequencies, we made a reasonable presumption that a uniaxial-like strain is exhibited in graphene on Cu(100). For a correction to the magnitude of the uniaxial strain, the mode Gruneisen parameters at room temperature are estimated to be about similar to 1.8 for the G bands, in reasonable agreement of the literature values. This strategy made it possible to estimate the temperature-dependent mode Gruneisen parameters of the G and G' bands for the first time.