Ionic Sieving Through One-Atom-Thick 2D Material Enables Analog Nonvolatile Memory for Neuromorphic Computing

The first report on ion transport through atomic sieves of atomically thin 2D material is provided to solve critical limitations of electrochemical random-access memory (ECRAM) devices. Conventional ECRAMs have random and localized ion migration paths; as a result, the analog switching efficiency is inadequate to perform in-memory logic operations. Herein ion transport path scaled down to the one-atom-thick (approximate to 0.33 nm) hexagonal boron nitride (hBN), and the ionic transport area is confined to a small pore (approximate to 0.3 nm(2)) at the single-hexagonal ring. One-atom-thick hBN has ion-permeable pores at the center of each hexagonal ring due to weakened electron cloud and highly polarized B-N bond. The experimental evidence indicates that the activation energy barrier for H+ ion transport through single-layer hBN is approximate to 0.51 eV. Benefiting from the controlled ionic sieving through single-layer hBN, the ECRAMs exhibit superior nonvolatile analog switching with good memory retention and high endurance. The proposed approach enables atomically thin 2D material as an ion transport layer to regulate the switching of various ECRAM devices for artificial synaptic electronics.

Automated summary

The report highlights the use of atomic sieves in atomically thin 2D materials to address limitations in ECRAM devices, resulting in efficient ion transport paths and analog switching efficiency. The one-atom-thick hBN confines the ion transport area to small pores within each hexagonal ring, with experimental evidence showing an activation energy barrier of approximately 0.51 eV for H+ ion transport through single-layer hBN.