Memristive logic device is a promising unit for beyond von Neumann computing systems and 2D materials are widely used because of their controllable interfacial properties. Most of these 2D memristive devices, however, are made from semiconducting chalcogenides which fail to gate the off-state current. To this end, a crossbar device using 2D HfSe2 is fabricated, and then the top layers are oxidized into "high-k" dielectric HfSex Oy via oxygen plasma treatment, so that the cell resistance can be remarkably increased. This two-terminal Ti/HfSex Oy /HfSe2 /Au device exhibits excellent forming-free resistive switching performance with high switching speed (<50 ns), low operation voltage (<3 V), large switching window (103 ), and good data retention. Most importantly, the operation current and the power consumption reach 100 pA and 0.1 fJ to 0.1 pJ, much lower than other HfO based memristors. A functionally complete low-power Boolean logic is experimentally demonstrated using the memristive device, allowing it in the application of energy-efficient in-memory computing.
Keywords: 2D HfSe2; in-memory computing; low-power consumption; memristors; oxidation; resistive switching.
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