Effective ways to enhance the performance of n-MoS2/p-CuO heterojunction based self-powered photodetectors

The present study has investigated two effective routes to improve the response time and the detection range for the n-MoS2/p-CuO (conventional p-n) heterojunction. In the first rectification, an insulating AlN layer was inserted between the MoS2 and CuO layer, which leads the traditional p-n junction to Semiconductor-Insulator-Semiconductor (SIS) with a superior carrier tunneling mechanism. Interestingly, the fabricated heterostructure exhibits self-powered and broad-range photoresponse. The response time (rise time and fall time) of the fabri-cated n-MoS2/p-CuO heterojunction decreases from 93.35 ms to 102.68 ms-11.31 ms and 12.73 ms with the insertion of ultrathin insulating AlN Layer. The higher responsivity and ultrafast photoresponse in n-MoS2/AlN/ p-CuO (SIS) heterojunction can be ascribed to the carrier tunneling mechanism through the ultrathin-insulating AlN layer. In the second rectification, the detection range can be enhanced up to the UV region by adding a layer of MoS2 quantum dots (QDs) on the surface of the MoS2 layer. The fabricated n-MoS2 QDs/n-MoS2/AlN/p-CuO heterostructure shows photoresponse in a broad range from UV to NIR radiations. The obtained results demonstrate the n-MoS2/AlN/p-CuO (SIS) heterostructure with the addition of MoS2 QDs shows excellent po-tential for next-generation ultrafast optoelectronics applications.

Automated summary

The present study proposes two effective routes to enhance the response time and detection range of the n-MoS2/p-CuO heterojunction. Firstly, by inserting an insulating AlN layer between MoS2 and CuO, the traditional p-n junction transforms into a Semiconductor-Insulator-Semiconductor (SIS) structure, achieving superior carrier tunneling mechanism. Secondly, the detection range is extended to the UV region by adding MoS2 quantum dots (QDs) on the surface of MoS2 layer. The results demonstrate that the n-MoS2/AlN/p-CuO (SIS) heterojunction with MoS2 QDs has great potential for next-generation ultrafast optoelectronics applications.