Anti‐Ambipolar Transistor Based on Van Der Waals Heterostructure Enables Gate‐Programmable Rectification

ABSTRACT

Multifunctional optoelectronic devices with programmable photoresponses and self‐powered capabilities are ideal candidates for next‐generation integrated electronics and intelligent sensing systems. However, this remains challenging due to the fixed, single interfacial barriers and limited tunability in conventional heterostructures. This work report a vertically stacked Bi ₂ Se ₃ /WSe ₂ /WS ₂ van der Waals heterostructure phototransistor that simultaneously exhibits gate‐programmable, anti‐ambipolar transport characteristics, broadband self‐powered photoresponses, and rectifying switching functions. Owing to the asymmetric energy band alignment and two series‐connected, gate‐reconfigurable interfacial barriers, the device demonstrates pronounced anti‐ambipolar transfer characteristics with dual conductivity peaks, leading to four distinct rectifying regimes. Among them, two gate‐selected rectifying regions exhibit forward rectification with a rectification ratio up to 10 ⁴ and excellent photodetection performance, including a responsivity exceeding 10 ⁵ A/W, a specific detectivity reaching 10 ¹⁵ Jones, an external quantum efficiency greater than 10 ⁷ %, and a relatively fast response speed on the microsecond scale. Notably, the device can operate in a self‐powered mode, achieving broadband self‐powered photoresponses across wavelengths from ultraviolet to visible and near‐infrared regions and displaying gate‐programmable polarity photocurrents. These features enable multi‐logic optoelectronic encoding, polarity optoelectronic imaging, and neural network‐assisted recognition, providing a versatile platform for low‐power‐consumption, programmable optoelectronics, intelligent imaging, and integrated multifunctional optoelectronic systems.