Memristors with tunable characteristics based on the tellurene/Nb-doped MoS2 heterojunction toward bio-realistic synaptic emulation

Emerging intelligence applications, such as brain-inspired and in-memory computing, require memory with faster read/write speeds, higher integration, and lower energy consumption. To tackle these challenges, memristors, a type of synaptic device, are considered ideal candidates due to their potential for emulating biological synaptic connections. In this study, a two-dimensional (2D) heterostructure of tellurene/Nb-doped MoS2 (MoS2:Nb) was used as the resistive switching layer to fabricate memristors. By varying the maximum working voltage, the fabricated device can switch between one and two-memory windows, which can be used to imitate the postsynaptic inhibition effect. This is attributed to the competition between the drift and diffusion of the S vacancy in the MoS2:Nb layer, which can modulate the contact Schottky barrier in the material interfaces. Furthermore, biological synapse effects, such as long-term depression and long-term potentiation, can be well mimicked by applying several voltage pulses to the device with good repeatability. This study advances the device physics for understanding the physical working mechanism of the 2D memristor, which can benefit the realization of bio-realistic neuromorphic computing systems based on such memristors.