4H‐SiC Homojunction Photogated Synapses Enabling High‐Temperature Neuromorphic Computing

Abstract Ultraviolet optoelectronic synapses (UVOSs) that can simultaneously perceive, memorize, and preprocess UV light signals hold great promise for applications in secure communication, fire warning, and planetary exploration. However, the thermal instability of current UVOSs significantly hinders their practical applications in harsh environments. In this work, high‐temperature‐resistant synaptic devices based on the p‐n 4H‐SiC homojunctions are demonstrated. The efficient separation of the photogenerated carriers at the homojunction interface induces a pronounced photogating effect, enabling robust light‐stimulated synaptic behavior even at 350 °C in ambient air without any encapsulation. The maximum operating temperature of these devices notably exceeds that reported for other UVOSs. Leveraging an array of these devices, information encryption and image learning‐memory are emulated at 350 °C. Moreover, the 4H‐SiC photogated synapse array recognizes handwritten digits with up to 95% accuracy in artificial neural network (ANN) simulations. This study provides a simple yet effective strategy for developing UVOSs for high‐temperature neuromorphic computing.