Photodetector of Heterostructure Formed by MoS 2 with Nb Doped WSe 2 enhances the photoresponsivity

The weak van der Waals interactions between 2D materials and metal electrodes mitigate the impact of Fermi-level pinning on device performance.Doping serves as a crucial method for adjusting material conductivity.This work fabricated MoS2/WSe2 and MoS2/WSe2 (Nb-doped) heterojunction photodetectors,both achieving light detection within the visible spectrum.The MoS2/WSe2(Nb)heterojunction photodetector outperformed the MoS2/WSe2 counterpart across all wavelengths.At 532 nm,it exhibited a responsivity of 1.38 A·W-1,a photodetection efficiency of 5.28 ×108 Jones,and an external quantum efficiency of 320.47 %.Doped carriers weaken the device's suppression of dark current while maintaining high photoresponsivity.This work demonstrates a doping-engineering strategy for regulating carrier transport in TMDC heterojunction photodetectors,providing new insights into the optimization of photoresponse performance beyond conventional heterostructure design.