Synergistic Amplification of Circularly Polarized Luminescence in Chiral Perovskite Films via Energy Transfer and Localized Surface Plasmon Resonance

Abstract

This work reports the in-situ synthesis of monolayer hybrid chiral perovskite films R/S-MBAPbBr₃@MBA₂PbBr₄ via temperature modulation, which combining the chiral one-dimensional (1D) R/S-MBAPbBr3 perovskite with two-dimensional (2D) non-luminescent (R/S-MBA)2PbBr4 perovskite. The as-synthesized chiral hybrid films exhibit stronger circularly polarized luminescence (CPL) response than that of the corresponding 1D chiral perovskite films. The circularly polarization-resolved transient absorption (TA) spectra reveal that the enhancement of CPL response stems from the energy transfer between chiral 2D perovskite structure and the defect states of chiral 1D perovskite structure, which can increase the imbalanced spin population in the defect levels. In addition, the CPL response can be further improved by combining the chiral perovskite hybrid films with achiral silver nanowires. TA spectra demonstrate that the localized plasma field enhances the carrier recombination rate without altering their spin polarization lifetime. This work provides guidance for the synthesis of chiral perovskite films with strong CPL response and further provides insight into the relevant mechanism of CPL enhancement.