Strong interface coupling for enhanced photoresponse in 1D BiInSe/2D WSe2 phototransistor

With the improvement of heterostructure preparation technology, research on the physical properties and device performance of mixed-dimensional heterostructures has been greatly developed. Numerous studies have focused on 2D/2D heterostructures, but research on 1D/2D heterostructures is comparatively limited, and the interface electron transfer mechanism needs to be further explored. In this study, we leverage the inherent band structure alignment characteristics of 1D Bi1.3In0.7Se3 and 2D WSe2 to create Bi1.3In0.7Se3/WSe2 heterostructure with Type-I band alignment. The results of PL, Raman, and KPFM prove the existence of a strong coupling effect at the heterostructure interface. The Bi1.3In0.7Se3 nanowire enhances the PL intensity and red-shifts the PL peaks of WSe2. This strong local electric field at the heterojunction interface improves the photoresponse performance of the Bi1.3In0.7Se3/WSe2 heterostructures devices. They achieve excellent photoresponce properties in a wide spectral range from solar-blind ultraviolet C (254 nm) to near-infrared (980 nm) region, with a large responsivity of 98 A/W, a high detectivity of 1.16 × 1013 Jones, and a fast photoresponse time of 500 μs. In addition, the optoelectronic performance of the device is controlled by modulating the Fermi level of the heterostructure by the applied gate electric field. Our work paves the way for the development of 1D/2D heterostructures for multifunctional optoelectronic applications.