Linear Photogalvanic Effect in Two-Dimensional WTe₂ Nanoribbons Under Tensile Strain

The linear photogalvanic effect (LPGE) in monolayer WTe 2 under tensile strain in both near-infrared and visible light regions is investigated by using non-equilibrium Green’s function technique (NEGF) combined with density functional theory (DFT). Our results show the magnitude of the strain changes the photoresponse, but the photoresponse is a nonlinear function of it. In addition, the extinction ratio can be altered by adjusting the strain. Applying strain in both the transmission and periodic directions of the monolayer will extend the detection range of the detector. In particular, the detection range is significantly expanded in the periodic direction, and is found to be positively correlated with the magnitude of the applied strain. Our results provide an efficient method for regulating and optimizing the photoresponse and polarization sensitivity through the application of tensile strain.