High-performance Self-Biased Photodetectors Based on Bi-incorporated ReSe2 Ternary Alloys

Transition Metal Dichalcogenides (TMDCs) have recently been the focus because of their unique physical properties. Bi-incorporated ReSe2 (Bi: ReSe2) is a new member of the TMDC family with a triclinic structure that is optically biaxial and strongly anisotropic. In this work, we reported the effect of Bi doping in layered ReSe2 crystals synthesized by the Direct Vapour Transport (DVT) method and studied the structural and optoelectronic properties in detail. The layered surface of the single crystals, the stoichiometric proportion of elements and the triclinic structure and phase purity of the material has been observed using Scanning electron microscopy (SEM), Energy dispersive analysis of X-ray (EDAX) and X-ray diffraction (XRD) respectively. The shifting in vibrational Raman modes has been observed by Raman spectroscopy at room temperature. The dynamic I-t characteristics of BixRe1-xSe2 (x = 0.1, 0.5) ternary alloy-based photodetectors were studied successively. The photodetector parameters were calculated under different biasing voltages and different wavelengths. The anisotropy in the dynamic I-t characteristics of transition metal chalcogenides was studied due to their layered structure. The device showed higher photoresponse for the perpendicular to c-axis configuration than for the parallel. Our results showed that the ternary alloys based single crystals have great potential for application in photosensitive devices.