Low operating voltage memtransistors based on ion bombarded p-type GeSe nanosheets for artificial synapse applications

Two-dimensional (2D) layered materials have many potential applications in memristors owing to their unique atomic structures and electronic properties. Memristors can overcome the in-memory bottleneck for use in brain-like neuromorphic computing. However, exploiting additional lateral memtransistors based on 2D layered materials remains challenging. There are few studies on p-type semiconductors that have not been theoretically analyzed. In this study, a lateral memtransistor based on p-type GeSe nanosheets is investigated. A three-terminal GeSe memtransistor that modulated the interfacial barrier height was fabricated using low-energy ion irradiation; the memtransistor exhibited a low operating voltage. The memtransistor successfully mimics biological synapse, including neuroplasticity functions, such as short-term plasticity, long-term plasticity, paired-pulse facilitation, and spike-timing-dependent plasticity. The mechanism of interfacial modulation was verified by experimental results and theoretical calculations. The results show that it is feasible to modulate the interface of 2D GeSe nanosheets using low-energy ion irradiation to realize a lateral memtransistor. This may provide promising opportunities for artificial neuromorphic system applications based on 2D layered materials.