Programmable Multilevel Memtransistors Based on van der Waals Heterostructures

Neuromorphic computing that mimics the energy-efficient cortical neural network in the human brain is attractive because of its possibility to process complex and massive data sets and achieve fast computing capability. Herein, a heterosynaptic and programmable memtransistor architecture with high computing functionality is reported by monolithically integrating a hexagonal boron nitride (h-BN) memristor with a molybdenum disulfide (MoS₂) transistor. Memristors consisting of a vertically stacked van der Waals materials (multilayer graphene (MLG) and h-BN) exhibit a stable bipolar resistive switching behavior with a memory window more than three orders of magnitude due to the formation and rupture of the metallic filament within the h-BN layer. By controlling the resistance state of the h-BN memristor, the behaviors of the memtransistor can be programmed with a high switching ratio of ≈10⁴, showing ≈16 pW standby power consumption. A multistate computing window and tunable current on/off ratio can be achieved by controlling the synaptic weight of the memristor, demonstrating that the presented 2D architecture can be exploited as a logic inverter device. The results pave the way toward the development of highly functional neuromorphic systems for the next-generation in-memory computing.