High-Performance MoS2 Photodetectors Prepared Using a Patterned Gallium Nitride Substrate.

Strain-adjusting the band gap of MoS2 using patterned substrates to improve the photoelectric performance of MoS2 has gradually become a research hotspot in recent years. However, there are still difficulties in obtaining high-quality two-dimensional materials and preparing photodetectors on patterned substrates. To overcome this, a continuous multilayer MoS2 film was transferred to a patterned gallium nitride substrate (PGS) for the fabrication of photodetectors, and density functional theory calculations showed that the band gap of the MoS2 film increased and that the electron effective mass decreased due to the introduction of PGS. In addition, finite difference time domain simulation showed that the electric field in the MoS2 area on the PGS is enhanced compared with that on the flat gallium nitride substrate due to the enhanced light scattering effect of the PGS. The photoresponse of the MoS2/PGS photodetector at 460 nm was also enhanced, with Iph increasing by 5 times, R increasing by 2 times, NEP decreasing to 3.88 × 10-13 W/Hz1/2, and D* increasing to 5.6 × 108 Jones. Our research has important guiding significance in adjusting the band gap of MoS2 and enhancing the photoelectric performance of MoS2 photodetectors.