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 MoS 2 /P–Si heterojunction with asymmetric electrodes was fabricated. The MoS 2 /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 MoS 2 /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 MoS 2 /P–Si heterojunction device with asymmetric electrodes on photovoltaic applications.