High‐Performance Non‐Volatile Flash Photomemory via Highly Oriented Quasi‐2D Perovskite

Abstract Solution‐processable organic–inorganic hybrid perovskite materials have been applied to a variety of optoelectronic devices due to its long exciton lifetime and small binding energy. It has emerged as promising front‐runners for next‐generation non‐volatile flash photomemory devices. However, the effect of crystal orientation of perovskite on the performance of photomemory still has not fully developed. Herein, non‐volatile flash photomemory with quasi‐2D perovskite/polystyrene‐block‐poly(ethylene oxide) (PS‐b‐PEO) as photoactive floating‐gate and p‐type semiconductor poly(3‐hexylthiophene‐2,5‐diyl) (P3HT) as the chare‐transporting layer is successfully demonstrated. By adding phenylethylammonium bromide (PEABr) in formamidinium lead bromide perovskite (FAPbBr₃), the crystal orientation of quasi‐2D perovskite is highly improved, which results in raised charge transfer efficiency from 76% to 90% compared to the pure FAPbBr₃. Furthermore, ON/OFF current ratio of 10⁴, low photo‐programming time of 5 ms under light intensity of 0.85 mW cm⁻², charge transfer rate of 0.063 ns⁻¹, and data storage capacity of over 7 bits (128 levels) in one cell can be achieved. In addition, the correlation between photo‐responsive current and photoluminescence (PL) is first examined by in operando PL measurement, which provides a new platform to explore the charge transfer process in photomemory.