Fig. 1.

Crossbar memory array of a self-selective van der Waals heterostructure and the working mechanism. a Schematic picture of the van der Waals heterostructure in the crossbar memory array architecture, differing from the traditional one-selector one-resistor and complementary resistive switching (see in the main text). b Current–voltage characteristics of a single memory cell. The four current and voltage ranges represent four different states of the memory cell. The selectivity of the self-selective cell is 10¹⁰, with a big memory window (10³). Our unit cell shows bipolar behavior. For the negative voltage direction, it is shown in Supplementary Fig. 7a. During the measurement, the top electrode (gold) was kept to connect the ground. c Schematic illustration of hexagonal boron nitride/graphene/hexagonal boron nitride layers for the four states in ‘b’. Ranges “1” and “3” represent the high-resistance state and low-resistance state of unselected cells, respectively. Ranges “2” and “4” represent the high-resistance state and low-resistance state of a selected memory cell, respectively. Conductive silver filaments are formed at a voltage of 2.6 V, enabling the read of the high-resistance state (range “2”) and low-resistance state (range “4”) in a voltage window from 2.6 to 4.0 V. The gray, purple, blue, and yellow spheres represent silver, hexagonal boron nitride, graphene, and gold layer, respectively. The white spheres in the top hexagonal boron nitride layer represent the boron vacancies in hexagonal boron nitride