▎ 摘　　要

Electron-phonon coupling strength was studied in graphene-MgB2 composites to explore the possibilities for a higher superconducting transition temperature (T-c). For the first time in the experimental work on MgB2, the Raman active E-2g mode was split into two parts: a softened mode corresponding to tensile strain and a hardened mode attributed to the carbon substitution effect. The tensile strain effect is suggested to improve T-c of graphene-MgB2 composites because it increases the electron-phonon coupling strength of MgB2.