High Responsivity Graphene-Metal Heterostructure Photodiodes for Low-Intensity Light Detection

This study investigates the photoresponse behavior of photodiodes fabricated using graphene-metal heterostructures. Our findings indicate that these devices exhibit a slightly sub-linear photoresponse as a function of incident intensity, resulting in high responsivities at low incident intensities. Among the devices tested, one exhibited the highest extrinsic responsivity of 148 mA W−1 at 1550 nm under a low bias voltage of VDS = 0.3 V. This performance is comparable to that of the leading waveguide integrated two-dimensional detectors.