We report an innovative method for chlorine doping of graphene utilizing an inductively coupled plasma system. TEM analysis reveals that the pre-doping (doping before wet transfer) and normal-doping (doping after wet transfer) were generally formed and trapped well between graphene layers; moreover, by thermal stability testing, the chlorine-trapped layer-by-layer graphene showed a very high thermal stability in vacuum at 230 °C for 100 hours. We also obtained the sheet resistance and optical transmittance of the Cl-trapped tri-layer graphene at 72 Ω sq−1 and 95.64% at 550 nm wavelength, respectively. In addition, the high hole mobilities for the chlorine-trapped bi- and tri-layer graphene were observed up to 3352 and 3970 cm2 V−1 s−1, respectively.
