▎ 摘　　要

A high-quality HCa2Nb3O10 (HCNO) nanoflake (epsilon(r) = 9.1) consisting of high-kappa perovskite nanosheets is adopted as a gate dielectric for graphene-based electronics. A dual-gated device was physically constructed by directly dry-transferring a 22-nm-thick HCNO nanoflake as a top gate dielectric onto graphene. The fabricated graphene field-effect transistor could be operated at biases <1.5V with a gate leakage below 1 pA. The top-gate capacitance and mobility of the dual-gated graphene device at room temperature were estimated to be 367 nF/cm(2) and 2500 cm(2)/V.s, respectively. These results show that HCNO can be employed as an alternative dielectric for graphene-based devices. (C) 2013 AIP Publishing LLC.