Engineering in 2D violet phosphorus/PdSe2 van der Waals heterostructures for advanced optoelectronics

Abstract Two-dimensional (2D) van der Waals (vdWs) heterostructures have rapidly become promising platforms for advanced optoelectronic devices, mainly due to their extraordinary capability to control electronic and optical properties at atomically abrupt interfaces. However, realizing high-performance optoelectronics strongly relies on precise engineering at these interfaces to optimize charge carrier generation, transport, and extraction efficiencies. In this work, we present a comprehensive theoretical and experimental study of VP/PdSe 2 vdWs heterostructure targeting photodetector. Our findings indicate that VP/PdSe 2 vdWs heterostructures exhibit a type-I band alignment, enabling photodetection across the visible (VIS) to near infrared (NIR) spectral regions. By introducing graphene as a contact layer (Gr/VP/PdSe 2 ), we significantly enhanced device performance, achieving a remarkable responsivity of 111.3 AW −1 and an external quantum efficiency of 26001%, representing an enhancement of about three orders of magnitude compared to the bare VP/PdSe 2 devices. Moreover, the engineered photodetector demonstrated superior stability, maintaining consistent performance over 100 operational cycles, and an exceptionally fast photoresponse time of approximately 10 ms. Additionally, the device showed robust polarization-sensitive detection capabilities with an impressive dichroism ratio across a broad spectrum. This work paves the way to realize innovative 2D heterostructure for high-performance, multifunctional optoelectronic applications.