A Novel Approach for the Fabrication of Polarization‐Selectivity UV Photosynapse Devices With PdSe ₂ / a ‐plane GaN Heterostructures

High polarization‐selectivity UV photodetectors with multifunctional integration play a crucial role in the next‐generation optoelectronic devices. However, weak and unruly dichroism radio (DR) of naturally anisotropic materials seriously restricts the detection accuracy and practical application, especially for wide‐bandgap materials with rough surfaces and inherent weak anisotropy. In this work, a novel approach for the polarization‐selectivity UV photosynapse devices with PdSe 2 / a ‐plane GaN heterostructures has been proposed. A simple pre‐selenization treatment is employed to enhance the anisotropy (DR = 16) and crystallinity of PdSe 2 , addressing the current limitation of insufficient anisotropy (DR<5) that hinders the practical application. The devices take advantage of inherent anisotropic materials and synergistic effect from the in situ growth of PdSe 2 on a ‐plane GaN, resulting in an enhancement of anisotropic photocurrent ratio from 1. 6 to 10.7. Thanks to the synergistic effect of the whole device architecture, the devices reveal an ultra‐long relaxation time of up to 282s and effectively improve the details of image recognition, speed up calculations, and accurate detection capabilities. The combination of high polarization‐selectivity, accurate detection, ultra‐long memory, and outstanding data processing capabilities establishes the photodetector as a promising candidate for the on‐chip integration of multi‐information carrying, processing, and neuromorphic computing.