Ultra-low turn-off current 2D material heterojunction selectors: first-principle calculations

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Selector is important for emerging non-volatile memory arrays to settle the sneak path problem and inhibit the array leakage current. The turn-off current of the selector determines the ability of selector to inhibit the leakage current. Here, selector models with the structure of graphene/g-GaN/graphene show ultra-low turn-off current. First, combining the plane electrostatic potential and the current–voltage characteristic of switch layers of heterojunctions, it can be concluded that the resistance switching mechanism is based on Schottky barrier at the interface. Moreover, three selector models with different switch layers (model A, B, C) are explored to study the influence of the switch layer structure on the device. The plane average electrostatic potential of selectors shows that the different structures of the switch layer result in the difference of the threshold voltage (V th), owing to the different interface barrier. Finally, the electronic transmission shows each selector have an ultra-low turn-off current (I off) and high nonlinearity, which could better suppress the leakage current in array. This work supplies a potential implementation scheme for the selector with ultra-low turn-off current.