▎ 摘　　要

There has been significant research on graphene as a sensor owing to the inherent high sensitivity and surface area associated with two-dimensional (2D) materials. Often, the ability of graphene to form heterojunctions with wide-bandgap semiconductors is overlooked. In this study, we present a detector based on an epitaxial graphene/SiC heterojunction, exploiting the 2D nature of graphene to minimize absorption losses for high-efficiency sensing while simultaneously taking advantage of the epitaxial p-n junction to achieve low reverse leakage. We measured a quantum efficiency above 80% at 4 eV using a graphene/SiC p-n heterojunction with a dark current <1nA/cm(2). (C) 2015 The Japan Society of Applied Physics