▎ 摘　　要

Graphene shows great promise as a transparent conductive electrode for optoelectronic applications. However, residues generated during the graphene transfer process lead to the degradation of device performance. Here, we show that a combination of UV/ozone pretreatment with the conventional process of graphene transfer can help in obtaining a large area graphene film with a clean surface on arbitrary substrates. In general, after CVD growth, a graphene film would be formed on both bottom and upper surfaces of a Cu foil. With UV/ozone pretreatment, a graphene layer with an undamaged and clean surface can be obtained, which is free of the residues. In addition, the quality of the obtained graphene can also be improved, which is revealed by the increase of the I-2D/I-G ratio from 2.0 to 3.6 for graphene films prepared without and with UV/ozone pretreatment, respectively. The transferred graphene films show higher transparency (97.5% at 550 nm), and the electron mobility (1178 cm(2) V-1 s(-1)) can be improved by a factor of two compared to that prepared by the conventional transfer process (685 cm(2) V-1 s(-1)). Considering its high efficiency, low cost, and easy scalability, the UV/ozone-assisted transfer method can be beneficial to the performance of graphene-based device applications such as transparent conducting electrodes.