Realization of graphene field-effect transistor with high-κ HCa_2Nb_3O_(10) nanoflake as top-gate dielectric

摘要

A high-quality HCa_2Nb_3O_(10) (HCNO) nanoflake (ε_r = 9.1) consisting of high-κ 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 ＜1.5 V with a gate leakage below 1pA. 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.