Energy-Efficient Synaptic Device Based on Planar Structure H-Bn Memristor

Synapses with short-term plasticity (STP) and long-term plasticity (LTP) behaviors are the key factors for the development of complex neuromorphological systems. Two dimensional (2D) materials have shown great potential at synaptic devices because of their unique properties. In this work, synaptic device with a planar structure using insulated 2D hexagonal boron nitride (h-BN) as resistance switching (RS) medium was studied. The Ag/h-BN/Ag device exhibited a low operation current down to 0.1 nA, and coexistence of volatile and non-volatile RS characteristic is achieved by adjusting the SET power. The device efficiently mimicked the short-term plasticity (STP), and the energy consumption per synaptic event was as low as ~170 fJ per spike. The transition from STP to long-term plasticity (LTP) can be achieved when the energy consumption per synaptic event reached ~540 fJ/spike. In addition, the multi-memory states of synaptic devices can be obtained by adjusting the postsynaptic current (PSC)