Enhanced photoresponse characteristics of transistors using CVD-grown MoS2/WS2 heterostructures.

Semiconductor heterostructures based on transition metal dichalcogenides provide a broad platform to research two-dimensional nanomaterials and design atomically thin devices for fundamental and applied interests. The MoS 2 /WS 2 heterostructure was prepared on SiO 2 /Si substrate by chemical vapor deposition (CVD) in our research. And the optical properties of the heterostructure was characterized by Raman and photoluminescence (PL) spectroscopy. The similar 2 orders of magnitude decrease of PL intensity in MoS 2 /WS 2 heterostructures was tested, which is attribute to the electrical and optical modulation effects are connected with the interfacial charge transfer between MoS 2 and WS 2 films. Using MoS 2 /WS 2 heterostructure as channel material of the phototransistor, we demonstrated over 50 folds enhanced photoresponsivity of multilayer MoS 2 field-effect transistor. The results indicate that the MoS 2 /WS 2 films can be a promising heterostructure material to enhance the photoresponse characteristics of MoS 2 -based phototransistors. [ABSTRACT FROM AUTHOR]