NiPS 3 /GaN photodetector with bias‐selected photoresponse mode for reconfigurable optoelectronic logic and neuromorphic vision

Abstract Van der Waals heterostructures based on two‐dimensional materials provide a broad platform for the design of high‐performance optoelectronic devices. Nevertheless, the development of elegant device architectures capable of broadband spectral detection, while maintaining inherent compatibility with emerging functionalities such as optical imaging, optoelectronic synaptic simulation, and reconfigurable logic operations, remains a significant challenge. This article reports a multifunctional photodetector based on NiPS 3 /GaN type‐II band alignment heterostructure. The device exhibits a broad spectral response from ultraviolet (365 nm) to visible light (700 nm), and its photocurrent is five orders of magnitude higher than that of an isolated‐material device. By introducing graphene as the contact layer, the response speed of the device is doubled, while its responsivities under 365 and 450 nm illumination are enhanced from 2.4 A/W and 54.8 mA/W to 18.2 A/W and 206.9 mA/W, respectively, representing a several‐fold increase. Further research reveals that the competitive relationship among the photothermoelectric, photovoltaic, and photoconductive effects in the heterostructure can be dynamically controlled by adjusting the bias voltage, thereby achieving effective modulation of the device's transient response behavior. Based on this physical mechanism, the device demonstrates application potential in ultraviolet imaging, photoelectric synapses (achieving 94.7% handwritten digit recognition accuracy), and reconfigurable optical logic gates. This work provides a new design idea for the development of multifunctional wide‐spectrum photodetectors.