▎ 摘　　要

The radio-frequency, i.e. 0.5-40 GHz, characteristics of chemical vapor deposition-grown graphene monolayer via HNO3 doping is experimentally investigated. According to the obtained results, the sheet resistance of HNO3-treated graphene decreases about half compared to bare graphene. In the case of radio-frequency characteristics, the transmission coefficient and effective conductivity of the HNO3-treated graphene are more enhanced than those of the bare graphene. Moreover, the intrinsic resistance and inductance of the HNO3-treated graphene itself show diminishing tendency with frequency increase. As a result, it is verified that the direct current as well as high frequency characteristics of graphene are improved by using the chemical doping method. (C) 2014 Elsevier Ltd. All rights reserved.