Bidirectional optically modulated In2O3 transistors with inorganic solid electrolyte gating for neuromorphic visual systems

Abstract

Inspired by retinal visual processing, we demonstrate a bidirectional optically controlled neuromorphic In2O3 transistor based on an inorganic solid electrolyte Li1+xAlxTi2-x(PO4)3 (LATP) gate dielectric. The device exhibits light-controlled bidirectional visual bipolar cell behavior, exhibiting excitatory and inhibitory responses under ultraviolet (275 nm) and green light (520 nm) stimuli, respectively. X-ray photoelectron spectroscopy and capacitance–frequency measurements reveal that mobile Li+ ions in the LATP dielectric layer can adsorb electrons and form Coulombic binding states, thereby dynamically modulating photogenerated carrier transport. Optical pulse trains dynamically regulate the channel current, enabling bidirectional optical neural plasticity. Furthermore, a large-area device array was employed for image encoding and retinal damage simulation, highlighting its potential for artificial vision and neuromorphic computing. These findings establish an effective strategy for developing bidirectional optical, reconfigurable, and large-scale integrable neuromorphic devices, providing additional insights into the role of dielectric layer ion dynamics in neuromorphic optoelectronics.