▎ 摘　　要

The tuning of charge carrier density of graphene is an essential factor to achieve the integration of highefficiency electronic and optoelectronic devices. We demonstrate the reversible doping in graphene using deep ultraviolet (UV) irradiation and treatment with O-2 and N-2 gases. The Dirac point shift towards a positive gate voltage of chemical vapor deposition grown graphene field-effect transistors confirms the p-type doping, which is observed under UV irradiation and treatment with O-2 gas, while it restores its pristine state after treatment with N-2 gas under UV irradiation. The emergence of an additional peak in the X-ray photoelectron spectra during UV irradiation and treatment with O-2 gas represents the oxidation of graphene, and the elimination of this peak during UV irradiation and treatment with N-2 gas reveals the restoration of graphene in its pristine state. The shift in the G and 2D bands in Raman spectra towards higher and then lower wavenumber also suggests p-type doping and then reversible doping in graphene. The controlled doping and its reversibility in large area grown graphene offer a new vision for electronic applications.