Reconfigurable, Nonvolatile, Optoelectronic Synaptic Memtransistor Based on MoS2/Te van der Waals Heterostructures

Memtransistors with nonvolatile storage, reconfigurability, and simulated synaptic functions are critical to overcoming the traditional von Neumann computer architecture bottleneck. Emerging two-dimensional van der Waals heterostructures (vdW) are promising candidates for constructing advanced three-terminal memtransistors by integrating the intriguing features of different materials and offering additional controllability over their existing optoelectronic properties. Herein, molybdenum disulfide (MoS2)/Tellurene (Te) vdW p-n junction memtransistors are fabricated to mimic the plasticity, multi-bit memory, and paired-pulse facilitation behavior of biological synapses. The high surface potential difference and charge trapping of the MoS2/Te heterostructure can endow the device with reconfigurable functionality through the transformation from short-term plasticity to long-term plasticity under illumination. Meanwhile, optoelectronic synaptic memtransistors also demonstrate nonvolatile behavior with a long retention time up to several hours, which can realize optical potentiation and electrical depression in one synaptic activity. On this basis, a logical operation of "OR" is realized by controlling the optical and electrical inputs. Moreover, artificial neural network training is performed to achieve a high recognition accuracy of 87.8% for handwritten digit recognition, demonstrating the potential of the artificial optoelectronic synapses in neuromorphic calculation.