Ultraviolet Irradiation-Induced High Performance InZnO Thin-Film Transistors and Optoelectronic Synapse Devices

This article reports a high performance amorphous InZnO thin-film transistor (a-IZO TFT) and optoelectronic synapse device through a short-duration ultraviolet-ozone (UV-Ozone) treatment process. After UV-Ozone optimization, the IZO TFT demonstrates a high mobility of 28.42 cm²/V⋅s at a low operating voltage of 3 V, with a subthreshold swing (SS) as low as 89.2 mV/dec and an $\textit{I}_{\biosc{on}}$/$\textit{I}_{\biosc{off}}$ ratio up to 2.56 × 10⁸. Based on this IZO transistor, a resistive-load inverter was constructed, showing ideal swing characteristics and a high voltage gain of 22 at 3.5 V. Furthermore, using this inverter, received optical signals were converted into voltage signals, achieving important visual synaptic functions such as excitatory postsynaptic potential (EPSP), paired-pulse facilitation (PPF), short-term to long-term memory (LTM) transitions, and image array memory. Finally, based on optical synaptic relaxation dynamics, reservoir computing (RC) simulations achieved a speech recognition rate of 91%. These results highlight the immense potential of this a-IZO TFT for applications in display driving, neuromorphic systems.