Si–MoS2 Vertical Heterojunction for a Photodetector with High Responsivity and Low Noise Equivalent Power (original) (raw)

In this study, we propose the fabrication of a photodetector based on the heterostructure of p-type Si and n-type MoS 2. Mechanically exfoliated MoS 2 flakes are transferred on to a Si layer; the resulting Si-MoS 2 p-n photodiode shows excellent performance with a responsivity (R) and detectivity (D*) of 76.1 A/W and 10 12 Jones, respectively. In addition, the effect of the thickness of the depletion layer of the Si-MoS 2 heterojunction on performance is investigated using the depletion layer model; based on the obtained results, we optimize the photoresponse of the device by varying the MoS 2 thickness. Furthermore, low-frequency noise measurement is performed for the fabricated devices. The optimized device shows a low noise equivalent power (NEP) of 7.82 10-15 W Hz-1/2. Therefore, our proposed device could be utilized for × various optoelectronic devices for low-light detection.