High Response, Self-Powered Photodetector Based on the Monolayer MoS2/P-Si Heterojunction with Asymmetric Electrodes.

Here, a self-powered photodetector based on the monolayer MoS2/P-Si heterojunction with asymmetric electrodes was fabricated. The MoS2/p-Si heterojunction photodetector with asymmetric electrodes offers the advantages over the conventional heterojunction photodetector on optoelectronic applications in terms of strong built-in electric field and fast photogenerated carrier separation and transport. Significantly, the MoS2/P-Si heterojunction exhibited an obvious photovoltaic effect, which can be used as the self-powered photodetector operating without any bias voltage. At a voltage bias of 0 V, the photocurrent of the detector is 23 nA, and its photoresponse/recovery time is 84 ms/136 ms. When at bias, the detector shows a ratio of photocurrent to dark current up to 3120, high responsivity of 117 A W-1, and fast photoresponse/recovery time of 74 ms/115 ms. Our work illustrates the great potential of the MoS2/P-Si heterojunction device with asymmetric electrodes on photovoltaic applications.