Responsivity to solar irradiation and the behavior of carrier transports for MoS2/Si and MoS2/Si nanowires/Si devices

Abstract

The behavior of carrier transports and the responsivity to solar irradiation are studied for MoS2/n-type Si (n-Si) and MoS2/Si nanowires (SiNWs)/n-Si device. The MoS2 thin films were prepared by the sol–gel method. The MoS2/n-Si and MoS2/SiNWs/n-Si devices exhibit reliable rectification behavior. The thermionic emission-diffusion model is the dominant process in these fabricated MoS2/n-Si and MoS2/SiNWs/n-Si devices. By applying the insertion of the SiNWs, the responsivity to solar irradiation can be effectively increased. Because of the low reflectance values for the MoS2/SiNWs/n-Si sample, the increased photocurrent density for the MoS2/SiNWs/n-Si device is due to high external light injection efficiency. MoS2/SiNWs/n-Si devices benefit from the high surface to volume ratio for SiNWs leading to a high responsivity of the device. The photo-response results confirm that the decay in the photocurrent is due to the dominance of short-lifetime electron trapping in the MoS2 thin film.