High-speed energy-efficient memristor confined in sub-5 nm space with elemental oxygen reservoir layer.

Random migration of oxygen vacancies (VO) leads to unpredictable formation and rupture of conductive filaments (CFs) in oxide-based memristors. In this work, an atomically flat 4.5 nm hafnium oxide (HfOx) switching layer and a 3.5 nm elemental oxygen reservoir (EOR) layer are confined between two-dimensional HfS2 and MoS2 layers, ensuring a homogeneous electric field distribution. The migration and redistribution of VO within the ultrathin HfOx switching layer enable the memristive behavior of the device. The EOR-based memristors achieve high set/reset transition speeds of 8 ns and 15 ns, respectively. The electroneutral EOR layer interacts with VO in the HfOx switching layer and, together with the HfOx tunnel layer above the HfS2, forms a barrier to suppress the high-resistance state current. Reliable endurance up to 105 cycles, and long retention up to 105 s are simultaneously obtained. Finally, a high recognition accuracy of 97.0% is achieved, demonstrating potential for low-power neuromorphic computing applications.