Controlling sulfurization of 2D Mo2C crystal for Mo2C/MoS2-based memristor and artificial synapse.

Owing to the conductance-adjustable performance, the emerging two-terminal memristors are promising candidates for artificial synapses and brain-spired neuromorphic computing. Although memristors based on molybdenum disulfide (MoS₂) have displayed outstanding performance, such as thermal stability and high energy efficiency, reports on memristors based on MoS₂ as the functional layer to simulate synaptic behavior are limited. Herein, a homologous Mo₂C/MoS₂-based memristor is prepared by partially sulfuring two-dimensional Mo₂C crystal. The memristor shows good stability, excellent retention (~10⁴ s) and endurance (>100 cycles), and a high ON/OFF ratio (>10³). Moreover, for comprehensively mimicking biological synapses, the essential synaptic functions of the device are systematically analyzed, including paired-pulse facilitation (PPF), short-term plasticity (STP), long-term plasticity (LTP), long-term depression (LTD), and the transitions from STP to LTP. Notably, this artificial synapse could keep a high-level stable memory for a long time (60 s) after repeated stimulation. These results prove that our device is highly desirable for biological synapses, which show great potential for application in future high-density storage and neuromorphic computing systems. [ABSTRACT FROM AUTHOR]