Tunable ionic and photonic kinetics in InGaCdO broadband optoelectronic synapses for multimodal perception

Biological neural systems achieve multidimensional coupling of perception, memory, and processing through hierarchical information-integration mechanisms, enabling remarkably energy-efficient multimodal information computing. Inspired by this biological paradigm, we report an amorphous indium–gallium–cadmium–oxide (InGaCdO) optoelectronic synaptic transistor that exhibits tunable synaptic dynamics arising from the rich kinetics of ion-gated and photogenerated carriers in the oxide channel. Under optical and electrical stimuli, the device demonstrates typical synaptic plasticity behaviors, including excitatory postsynaptic current, paired-pulse facilitation, and spike-number-dependent plasticity. Leveraging this multimodal processing capability, we construct a reservoir computing system with integrated multisensory fusion. The multimodal system demonstrates a notable improvement in visual–audio recognition tasks, achieving a high accuracy of 91.3%. This study provides a device-level foundation for multimodal information-processing architectures and may facilitate the development of multisensory fusion intelligent systems and soft robots.