Due to their atomically ultrathin thickness, the development of high-performance transition-metal dichalcogenides (TMDCs) based photodetectors demands device designs distinct from architectures adopted in conventional bulk semiconductor devices. Here, we demonstrate a field-induced Schottky barrier photodiode with three different TMDC materials, WSe2, MoTe2, and WS2. Owing to the high gate efficiency of a high-κ dielectric film, the Schottky barrier at metal contacts is effectively modulated by external bias, giving rise to a strong diode-like rectifying characteristic with high current on/off ratio. The WSe2 photodiode shows a linear dynamic range of 112 dB, a responsivity of 0.17 A/W, and response time of 8 ns. When this fast WSe2 device is employed for visible light communication data linking, a maximum real-time data transmission rate of 110 Mbps is achieved. Meanwhile, infrared light communication was also realized with a maximum data rate of 30 Mbps using a field-induced MoTe2 Schottky barrier photodiode as a light sensor. This work provides a general CMOS-compatible and controllable fabrication strategy for TMDC-based photodetectors.
Keywords: Schottky photodiodes; high-κ gate dielectrics; light communication; photodetectors; transition-metal dichalcogenides.