TMD Heterostructures for High-Performance Photodetection

Po-Wen Chiu^1*, Chang-Hua Liu¹

¹Electrical Engineering, National Tsing Hua University, Hsinchu, Taiwan

* Presenter:Po-Wen Chiu, email:pwchiu@ee.nthu.edu.tw

Atomically thin transition metal dichalcogenides (TMD) and graphene are intriguing layered materials and show exotic optoelectronic properties for light sensing ranging from visible to infrared regimes. The intrinsic photoresponsivity for graphene is low due to the fast electron-hole recombination, whereas the photoresponsivity is strongly correlated with the contact configuration for TMD monolayer. Here, I will first show the growth of TMD heterostructures which can be applied to enhance the photosensing capability for both graphene and TMD monolayer. The type-II band alignment in most TMD heterostructures are beneficial in the sense that photo-excited electrons can be gathered in one material and holes can be accommodated in the other, effectively separating the two types of charge carriers and boosting the photosensing capability for the composite photodetectors comprising of TMD heterostructures. For graphene and TMD composite photodetectors, the responsivity can, respectively, reach 106 and 108 mA/W, a record high value up to date. A rich variety of new applications can be further explored using the conventional device architecture combined with the TMD heterostructures.

Keywords: Transition metal dichalcogenides, Graphene, Heterostructure, Photodetector