High-performance graphene/InSb heterojunction mid-infrared photogated diode

A high-performance graphene/InSb heterojunction mid-infrared (IR) photogated diode for use in IR image sensors was developed. This device exhibited low noise, owing to a significant reduction in the dark current, along with high responsivity. These characteristics are attributed to the heterojunction structure of the device and the associated photogating effect. The performance of this specimen was superior to those of conventional graphene-based IR sensors in the mid-IR wavelength range of 3-5 mu m. These results indicate that the combination of a simple graphene/InSb heterojunction and the photogating effect can produce IR image sensors with better detection performance than existing devices.