Multiexciton Generation From a 2D Organic-inorganic Hybrid Perovskite with Nearly 200% Quantum Yield of Red Phosphorescence.

Two dimensional (2D) organic-inorganic hybrid perovskites (OIHPs) show obvious advantages in the optoelectronic field due to their high luminescent stability and good solution processability. However, the thermal quenching and self-absorption of excitons caused by the strong interaction between inorganic metal ions lead to the low luminescence efficiency of 2D perovskites. Herein, we report a 2D Cd-based OIHP (named as PACC) with a weak red phosphorescence (Φ P < 6%) at 620 nm and a blue afterglow. Interestingly, Mn-doped PACC (PACC-M) exhibits very strong red emission with nearly 200% of quantum yield and 15 ms of lifetime, thus resulting in a red afterglow. The experimental data prove that the doping of Mn 2+ not only induces the multi-exciton generation (MEG) process of the perovskite, avoiding the energy loss of inorganic excitons, but also promotes the Dexter energy transfer from organic triplet excitons to inorganic excitons, thus realizing the super-efficient red-light emission of Cd 2+ . This work suggests that guest metal ions can induce host metal ions to realize MEG in 2D bulk OIHPs, which provides a new idea for the development of optoelectronic materials and devices with ultra-high energy utilization. This article is protected by copyright. All rights reserved.