Enhanced Optoelectronic Performance of CVD-Grown Metal-Semiconductor NiTe/MoS Heterostructures.

Van der Waals (vdW) heterostructures are the fundamental blocks for two-dimensional (2D) electronic and optoelectronic devices. In this work, a high-quality 2D metal-semiconductor NiTe/MoS heterostructure is prepared by a two-step chemical vapor deposition (CVD) growth. The back-gated field-effect transistors (FETs) and photodetectors based on the heterostructure show enhanced electronic and optoelectronic performance than that of a pristine MoS monolayer, owing to the better heterointerface in the former device. Especially, this photodetector based on the metal-semiconductor heterostructure shows 3 orders faster rise time and decay time than that of the pristine MoS under the same fabrication procedure. The enhancement of electronic behavior and optoelectronic response by the epitaxial growth of metallic vdW layered materials can provide a new method to improve the performance of optoelectronic devices.