Self-powered photodetector based on SnSe2/MoSe2 heterostructure. (December 2020) - Zankat, Chetan K.
Abstract: This article presents the influence of anisotropy of MoSe2 crystal on self-powered photodetection of SnSe2 /MoSe2 heterojunction. The atomic structure and polymorph confirmation of thermally evaporated SnSe2 thin film and direct vapor transport grown MoSe2 crystals were accomplished by powder X-ray diffraction, electron diffraction, and Raman spectroscopy. The heterojunction device exhibited obvious rectifying nature of n-n junction. The device exhibited type-II junction with high on/off ratio of 10 5 –10 6 which reflects its applicability in power generation without bias. The modulation of photoresponse is realized because of anisotropic charge transport in bulk MoSe2 crystal. The high-performance heterojunction exhibits photoresponsivity of 7.09 A/W, detectivity of 6.44 × 10 12 Jones, and external quantum efficiency of 1313% for top-top contact geometry, whereas these parameters are significantly reduced for top-bottom contact geometry. The influence of anisotropy and defect states on device performance is explained in detail. The SnSe2 /MoSe2 heterojunction with extremely good environmental stability and excellent self-driven photoswitching advocates huge development in optoelectronics. Graphical abstract: Image 1 Highlights: SnSe2 /MoSe2 heterojunction shows the self-powered photodetection. It exhibits high responsivity (7.09 A/W), detectivity (10 13 Jones), and external quantum efficiency (1313%). Effect of anisotropy and defect states on device performance is explained in detail. High on/off current ratio of 10 5 –10 6 is realized over 390–1088 nm spectral range.