High Gain and Broadband Absorption Graphene Photodetector Decorated with Bi2Te3 Nanowires.

A graphene photodetector decorated with Bi2Te3 nanowires (NWs) with a high gain of up to 3 × 104 and wide bandwidth window (400-2200 nm) has been demonstrated. The photoconductive gain was improved by two orders of magnitude compared to the gain of a photodetector using a graphene/Bi2Te3 nanoplate junction. Additionally, the position of photocurrent generation was investigated at the graphene/Bi2Te3 NWs junction. Eventually, with low bandgap Bi2Te3 NWs and a graphene junction, the photoresponsivity improved by 200% at 2200 nm (~0.09 mA/W).