n‐Involved Optimization of Out‐of‐Plane Optoelectronic Performances in Nanoscale Ruddlesden–Popper Perovskite

Abstract

Abstract Ruddlesden–Popper (RP) metal‐halide perovskites are attracting increasing attention due to their improved stability. The intercalated hydrophobic organic layer accounts for this improvement, however, it is detrimental to the out‐of‐plane optoelectronics. Here, the n‐involved performance optimization in RP (PEA)2(Cs)n−1PbnI3n+1 nanomaterials is reported. The exciton is confirmed as the majority of photo‐induced species, but it is more free carrier‐like in n‐larger samples due to the weakened quantum confinement effects. After 90‐day treatment in 65% humidity, it is found that only RP nanomaterials originally designed as n = 4 ((PEA)2(Cs)3Pb4I13) possess the best residual optoelectronic performances (photo‐responsivity and specific detectivity) at minimal drop proportions (≈20%). Particularly, the Coulombic screening effect triggers saturated optoelectronic performances at low driving voltage, due to the almost total depletion of responsive photo‐current even under enhanced external excitations. This work balances the optoelectronic performances and moisture resistance of PEA‐based RP nanomaterials, and is mainly aiming to alleviate the deterioration of optoelectronic performance in 90‐day moisture‐treated (65%) conditions.

Keywords

• Ruddlesden–Popper perovskites
• optoelectronic performances
• n
• moisture‐treatment