Programmable electric hysteresis in MoS2/graphene heterojunctions through twisting

Van der Waals (vdW) polytypes have recently been shown to enable remarkable field-effect control over electronic orders, including sliding ferroelectricity. In this work, we report robust electric hysteresis in MoS ₂ /graphite heterojunctions, with contact areas on the micrometer scale. The hysteretic behavior is programmable via interlayer twist, vanishing at a twist angle of 30°, indicating strong angle-dependent modulation. Owing to the superlubric nature of the interface, such manipulation can be performed rapidly and with minimal energy cost. The underlying mechanism is elucidated through the study of a monolayer graphene/MoS ₂ system, which exhibits a piezoelectric coefficient of d ₃₃ =5.2 pm/V. Density functional theory (DFT) calculations reveal that the electric response originates from a combination of interfacial charge transfer and moire potential effects, without requiring interlayer sliding to explain the observed hysteresis. This work shows that adjusting the twist angle in heterojunctions can control ferroelectric and piezoelectric properties, enabling better nanoelectronic devices.