Adaptive Self-powered Photodetection and Neuromorphic Computing in CuCrP2S6 Ionotronic Device

Abstract

In-sensor computing devices integrating sensing and processing functions are emerging as key enablers for next-generation artificial vision systems. Their development critically depends on identifying materials capable of mimicking the adaptive, multimodal behavior of biological synapses.Here we demonstrate CuCrP2S6 (CCPS), a two-dimensional metal thiophosphate, as an optoelectronic neuromorphic material that simultaneously supports photodetection and synaptic plasticity. The CCPS photodetector exhibits both strong photoconductive behavior and self-powered photoresponse at zero bias, through directional ion migration. It achieves a photoresponsivity of 420 mA/W and a specific detectivity up to 3.5×10 10 Jones. Crucially, both the magnitude and polarity of the photovoltaic current can be reversibly tuned by controlling ionic migration, mimicking the long-term potentiation and depression. A CCPS-based photonic synapse network achieves 89.8% image recognition accuracy on the Fashion-MNIST dataset, approaching the full-precision benchmark. Furthermore, a 3×3 CCPS photodetector array enables programmable spatial light response, facilitating in-sensor image preprocessing such as edge enhancement. This work highlights CCPS as a multifunctional material platform for integrated perception-computation electronics and paves the way for intelligent, on-chip visual processing systems.