Stimulating Efficient and Stable Ultralong Phosphorescence of 2D Perovskites by Dual-Mode Triplet Exciton Stabilization

Abstract

Ultralong room-temperature phosphorescence (URTP) has attracted widespread attention in modern optoelectronics, but it is mainly observed in organic materials through deliberate molecular design. Here, we report efficient URTP emission from two-dimensional (2D) perovskites by stabilizing the triplet excitons of organic cations energetically in a type I hybrid quantum-well-like structure and structurally in a 2D layered gallery. Such a dual-mode cooperative stabilization strategy is realized facilely by the methoxyl group modification of π-conjugated phenethylammonium cation, which has little influence on the 2D perovskite architecture. Moreover, a strong URTP (∼490 nm) with a remarkably long lifetime of up to 480 ms and quantum yield of 7.86% are achieved, along with excellent environmental robustness against moisture and oxygen invasion and good thermal stability in a wide range of temperatures. Furthermore, both multiple information encryption and afterglow white lighting devices are realized, greatly expanding the development of hybrid perovskite phosphors for advanced 2D URTP materials and applications.

Long Persistent Luminescence from Metal–Organic Compounds: State of the Art

“…[ 9 ] Moreover, recent study reveals that LPL could be achieved by doping organic fluorophores or phosphors into Pb II ‐based hybrid perovskites with wide bandgap, which would suppress the aggregation of organic chromophores and the formation of an inorganic free exciton for maximizing the LPL of organic chromophores. [ 28 ] The representative examples of metal–organic compounds and their LPL properties are listed in Table 1 .…”

“…Lv and Chen's group designed and synthesized various Pb‐based hybrid perovskites by modifying the functional group of phenethylammonium (PEA) (Figure 9b). [ 28 ] Compared with (PEA) 2 PbCl 4 (PPC), both (4MPEA) 2 PbCl 4 (4MPPC) and (3MPEA) 2 PbCl 4 (3MPPC) with electron‐donating methoxyl substituent on the phenyl ring exhibit ultralong RTP emission because the lone pair of electrons in methoxyl will promote n →π* transitions to facilitate ISC process. However, (4FPEA) 2 PbCl 4 (4FPPC) with electron‐withdrawing fluorine substitution reveals no ultralong RTP emission.…”

“…Reproduced with permission. [ 28 ] Copyright 2022, American Chemical Society. c) Single molecule and aggregate of coordination polymers exhibit different LPL colors.…”

“…b) Chemical structures of organic components in Pb-based hybrid perovskites. Reproduced with permission [28]. Copyright 2022, American Chemical Society.…”

Recent advances in ultralong room-temperature phosphorescence materials based on metal–organic halides

“…Compared with (BPMA) 2 PbBr 4 , the energy level mismatched (PEA) 2 PbBr 4 molecule exhibits a fluorescence lifetime of 1.13 ns at the main peak emission of its inorganic laminate, while (BPMA) 2 PbBr 4 exhibits a fluorescence lifetime of only 0.23 ns. DET efficiency can be calculated to be nearly 32 Copyright 2019, American Chemical Society. (f) Photographs taken under daylight, 365 nm UV light (UV on), and after removing the excitation source (UV off).…”