Photoassisted Electroforming Method for Reliable Low-Power Organic-Inorganic Perovskite Memristors

Organic-inorganic hybrid perovskite memristors with high resistive-switching (RS) reliability and low power consumption are crucial for high-density storage and high-efficiency neuromorphic computing. However, the current overshoot in the electroforming process generally induces overgrowth of conductive filaments (CFs) and degrades the RS performance. Here, a simple photo-assisted electroforming (PAE) method to suppress the current overshoot, in which the visible light irradiation is introduced into the initial electroforming process, is proposed for the first time. As a result, a reliable memristor with reduced RS fluctuation and enhanced cycling endurance is obtained, and also, the low operating current of 0.06 mA and low powerconsumption of 0.12 mW are achieved, which are about one order of magnitude lower than those of most reported hybrid perovskite-based memristors. Further experimental evidence indicates that light irradiation plays dual roles: 1) the light-induced lowering of iodide migration barrier leads to a significant reduction of overshoot current and forming voltage; 2) the enhanced local photoconductivity of the perovskite film shares the overshoot current through the CFs. Both factors limit the total quantity of vacancy defects generated in the electroforming process, thus preventing undesirable overgrowth of the CFs. The present PAE strategy has promise for developing high-performance memristors.