Gate‐Reconfigurable Multifunctional Photodetection Through Realigning Energy Band

ABSTRACT Integrating multiple optoelectronic functions into a single photodetector is highly desirable for next‐generation intelligent optoelectronics, yet remains challenging due to the reliance on complex device architectures and elaborate material engineering. Here, we demonstrate that realignment of the energy band‐induced electric field enables a simple type‑II van der Waals heterojunction composed of indium selenide and black phosphorus (InSe/BP) to realize gate‐reconfigurable bipolar photovoltaic and adaptive photoconductive operation. Under negative gate bias, electrostatic band reshaping drives a transition from type‑II to type‐I alignment while significantly enhancing the built‐in electric field at the InSe/BP interface, leading to a strong positive photovoltaic performance and effective suppression of dark current, with a photocurrent on/off ratio exceeding 10 5 . Conversely, a positive gate voltage restores the type‑II band alignment, yielding a negative photovoltaic response while simultaneously activating a high‐gain photoconductive regime. Beyond bipolar photovoltaic operation, an essential functionality for in‐sensor computing, the gate tunable‐adaptive photoconductive mode enables high‐contrast imaging across both bright and dim illumination conditions. This work establishes energy‐band realignment as a powerful and scalable strategy for multifunctional, gate‐reconfigurable photodetection, offering a promising platform for intelligent imaging and adaptive vision systems.