Extremely Low Operating Current Resistive Memory Based on Exfoliated 2D Perovskite Single Crystals for Neuromorphic Computing

TLDR

Neuromorphic computing demands extremely low energy consumption to match the brain’s parallel processing, yet conventional resistive memory materials cannot suppress electronic leakage while enabling ionic transport. The study aims to develop resistive memories with ionic transport and ultra‑low operating current, demonstrating that 2D Ruddlesden–Popper hybrid lead bromide perovskite single crystals are promising candidates due to their mixed transport and fabrication ease. The approach relies on the material’s mixed electronic and ionic transport to achieve ultra‑low operating currents, thereby reducing program, erase, and read currents for low‑power operation. Exfoliated 2D perovskite layers exhibit bromide ion migration, forming ~20 nm filaments that enable resistive memories with program currents as low as 10 pA—an order of magnitude below conventional materials—and support pA‑level ionic diffusion as an artificial synapse for ultra‑low‑energy neuromorphic computing.

Abstract

Extremely low energy consumption neuromorphic computing is required to achieve massively parallel information processing on par with the human brain. To achieve this goal, resistive memories based on materials with ionic transport and extremely low operating current are required. Extremely low operating current allows for low power operation by minimizing the program, erase, and read currents. However, materials currently used in resistive memories, such as defective HfOx, AlOx, TaOx, etc., cannot suppress electronic transport (i.e., leakage current) while allowing good ionic transport. Here, we show that 2D Ruddlesden–Popper phase hybrid lead bromide perovskite single crystals are promising materials for low operating current nanodevice applications because of their mixed electronic and ionic transport and ease of fabrication. Ionic transport in the exfoliated 2D perovskite layer is evident via the migration of bromide ions. Filaments with a diameter of approximately 20 nm are visualized, and resistive memories with extremely low program current down to 10 pA are achieved, a value at least 1 order of magnitude lower than conventional materials. The ionic migration and diffusion as an artificial synapse is realized in the 2D layered perovskites at the pA level, which can enable extremely low energy neuromorphic computing.