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

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 (FAPbBr(3)), 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 FAPbBr(3). Furthermore, ON/OFF current ratio of 10(4), 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.

Automated summary

By adding phenylethylammonium bromide (PEABr) to formamidinium lead bromide perovskite (FAPbBr(3)), the crystal orientation of quasi-2D perovskite is significantly improved, resulting in a higher charge transfer efficiency. The non-volatile flash photomemory shows an ON/OFF current ratio of 10^4, a low photo-programming time of 5 ms under light intensity of 0.85 mW cm(-2), a charge transfer rate of 0.063 ns(-1), and a data storage capacity of over 7 bits (128 levels) in one cell.