High Performance Self‐Driven Photodetectors Based on MoS2 Schottky Barrier Diode

Abstract

AbstractPractical application of two‐dimensional transition metal dichalcogenides (2D TMDCs) involves creating a p‐n diode and a Schottky diode. Unlike p‐n diodes, the research of 2D material‐based Schottky diodes especially in the application field of photodetectors is lacking. Here, a Schottky diode is fabricated by depositing Pt and Ni on the MoS2 to form Schottky and ohmic contacts, respectively. The MoS2 Schottky diode exhibits a rectification ratio of 2.36 × 103 and an ideality factor of 1.12. The electrical characteristics of Ni‐MoS2‐Ni and Pt‐MoS2‐Pt field effect transistors are systematically compared. The Schottky barrier height is estimated to be 94.2 meV by using the thermionic emission theory. The Schottky diode device can exhibit excellent self‐powered photodetection performance in the visible to near‐infrared region (447‐940 nm) due to the strong built‐in electric field originating from the Schottky barrier at the MoS2/Pt interface. The maximum detectivity reaches 2.09 × 1012 Jones with a response time of 52.6 ms under 940 nm laser illumination. Furthermore, the photodetection performance of such a Schottky diode can be further improved by NH3 plasma doping treatment. This work provides not only a simple approach to construct a 2D materials‐based Schottky diode photodetector but also a post treatment technique to further improve the device performance.