Amorphous InHfZnO/Ga ₂ O ₃ heterojunction by plasma-enhanced atomic layer deposition for transparent photoelectric synaptic devices with temperature-tunable mechanism analysis

Artificial photoelectric synaptic devices have exhibited remarkable advantages of low power consumption and high speed for neuromorphic computing. By integrating photodetection and memory functions, these devices offer a promising framework to resolve the limitations of von Neumann architectures. Herein, transparent photoelectric synaptic devices were fabricated based on amorphous InHfZnO/Ga₂O₃ heterojunction by plasma-enhanced atomic layer deposition. The heterojunction was comprehensively characterized with various techniques. For the fabricated devices, critical synaptic characteristics, including short-term plasticity (STP), paired-pulse facilitation (PPF), and long-term plasticity (LTP), were systematically characterized and evaluated under various optical conditions and temperatures. Based on temperature-dependent performance variations, the temperature-tunable mechanism of the devices was analyzed in terms of oxygen vacancy concentration evolution.