Dual‐Band Photodetection and Interfacial Carrier Dynamics of CuInP 2 S 6 /Ga 2 O 3 Van der Waals Heterojunction for Neuromorphic‐Like Recognition and Optical Communication

ABSTRACT A dual‐band device that can simultaneously possess high sensitivity and neuron‐like processing capabilities is highly desirable for next‐generation intelligent optoelectronic systems. However, traditional single‐material devices have the problems of poor performance and low integration level. Furthermore, due to their high‐power consumption, they are limited in applications such as integrated sensing, computing and storage, optical encryption communication, and imaging. Here, we report a multifunctional CuInP 2 S 6 (CIPS)/Ga 2 O 3 heterojunction that integrates ultraviolet (UV–Visible photodetection, artificial synaptic function, neuron‐like recognition, and dual‐wavelength optical communication and imaging. Notably, this constructed type‐II CIPS/Ga 2 O 3 van der Waals heterojunction provides an opportunity to modulate the interface charge carrier transport, then enhance the light absorbance, thereby achieving high responsivity (275 A/W), and enhanced detectivity (1.95 × 10 15 Jones) under irradiation of 245 nm UV light. Significantly, the device also exhibits vital synaptic plasticity, including dual‐pulse promotion and adjustable memory retention capability. By mapping the experimentally extracted single‐device forgetting dynamics to a simulated convolutional neural network framework, high accuracy has been achieved on both simple and complex datasets. Additionally, wavelength‐selective light response supports dual‐band UV‐visible light communication and imaging. This work establishes a multifunctional heterojunction platform, advancing the research and development of modern optoelectronics.