High-Responsivity and Broadband MoS Photodetector Using Interfacial Engineering.

Combining MoS with mature silicon technology is an effective method for preparing high-performance photodetectors. However, the previously studied MoS/silicon-based heterojunction photodetectors cannot simultaneously demonstrate high responsivity, a fast response time, and broad spectral detection. We constructed a broad spectral n-type MoS/p-type silicon-based heterojunction photodetector. The SiO dielectric layer on the silicon substrate was pretreated with soft plasma to change its thickness and surface state. The pretreated SiO dielectric layer and the silicon substrate constitute a multilayer heterostructure with a high carrier concentration and responsiveness. Taking silicon-based and n-type MoS heterojunction photodetectors as examples, its responsivity can reach 4.05 × 10 A W at 637 nm wavelength with a power density of 2 μW mm, and the detectable spectral range is measured from 447 to 1600 nm. This pretreated substrate was proven applicable to other n-type TMDCs, such as MoTe, ReS, etc., with certain versatility.