Quasi‐2D Perovskite with Ligand Engineering to Improve the Stability of Phototransistor Memory with a Floating Gate.

Quasi‐2D(two dimentional) perovskite is one of the potential materials in optoelectronic applications due to the scalable solution processes and low binding energy. Recent studies employing diverse spacer ligands of mono‐ and di‐amine functional groups to form Ruddlesden‐Popper (RP) and Dion‐Jacobson (DJ) phase perovskites efficiently manipulate the perovskite microstructure. However, there is a notable gap in investigating the performance of photomemory devices based on perovskites using different ligands and the accommodability in polymer matrixes. Herein, the perovskite with phenethylammonium bromide (PEABr) or p‐xylylenediamine (PDMA) ligands and methacrylate polymers comprising varied pendent groups (benzene and pyrene) are designed to investigate their effect. The results show that RP‐phase perovskite with polymer‐conferred pyrene group presented an excellent crystalline orientation, fewer grain boundaries, and higher charge transfer efficiency, attributed to superior accommodation between ligands and polymers and appropriate aggregation of pyrene groups. It demonstrates superior memory device characteristics of a high ON/OFF current ratio (2.68 × 104), low operational voltage (−0.1 V), short illumination times (0.1 s), and maintains its decent performance even under thermal environments. This work highlights that leveraging the steric hindrance of ligands and functional polymers to control the microstructure of perovskite is a prospective strategy to promote the photomemory's development. [ABSTRACT FROM AUTHOR]