Fig. 4: Photovoltaic characterisation of FePS₃-MoS₂.

a ΔI_DS–V_DS curves of the heterojunction with light excitation ranging from 455 to 660 nm. The inset shows an optical micrograph of the heterojunction area. b Photocurrent generated across the FePS₃‑MoS₂ junction when illuminated with illuminations of 455–660 nm and no applied bias (i.e. V_DS = 0 V). c Photocurrent mapping of the heterostructure with 635 nm laser at 0 V bias, indicating the highest photoresponsivity at the overlap region of FePS₃ and MoS₂. d Extracted short‑circuit current (I_SC) and open‑circuit voltage (V_OC) of the heterostructure with respect to different illumination wavelengths based on the ΔI_DS–V_DS curves.