Efficient Room‐Temperature Phosphorescence from Organic–Inorganic Hybrid Perovskites by Molecular Engineering

Abstract

Solution-processed organic-inorganic hybrid perovskites are promising emitters for next-generation optoelectronic devices. Multiple-colored, bright light emission is achieved by tuning their composition and structures. However, there is very little research on exploring optically active organic cations for hybrid perovskites. Here, unique room-temperature phosphorescence from hybrid perovskites is reported by employing novel organic cations. Efficient room-temperature phosphorescence is activated by designing a mixed-cation perovskite system to suppress nonradiative recombination. Multiple-colored phosphorescence is achieved by molecular design. Moreover, the emission lifetime can be tuned by varying the perovskite composition to achieve persistent luminescence. Efficient room-temperature phosphorescence is demonstrated in hybrid perovskites that originates from the triplet states of the organic cations, opening a new dimension to the further development of perovskite emitters with novel functional organic cations for versatile display applications.

Reversible Thermochromism and Strong Ferromagnetism in Two‐Dimensional Hybrid Perovskites

“…As a result, the optical and electronic properties of the materials can be tuned not only by metal cation and halide anion but also organic molecules with different sizes and functional groups, providing almost unlimited compositional and structural versatility. Given the vast design space for both organic and inorganic components, more “exotic” functions have also been envisioned with 2D hybrid perovskites, including singlet fission, room‐temperature phosphorescence and third harmonic generation …”

“…Given the vast design space for both organic and inorganic components,m ore "exotic" functions have also been envisioned with 2D hybrid perovskites,i ncluding singlet fission, room-temperature phosphorescence and third harmonic generation. [16][17][18][19] In stark contrast to conventional optoelectronic materials such as Si and GaAs,h ybrid halide perovskites are structurally softer due to weaker electrostatic interaction between the lattice ions. [20,21] Such structural "softness" results in ah ighly reconfigurable crystal structure with relatively easy structural rearrangements to undergo arich variety of solid-solid phase transitions under external stimuli.…”

Unraveling the mechanochemical synthesis and luminescence in MnII-based two-dimensional hybrid perovskite (C4H9NH3)2PbCl4

“…Two-dimensional (2D) organic-inorganic hybrid halide perovskites have been an important class of high-performance semiconductors and received significant attention in recent years due to their impressive structural diversity and the enormous potential in the fields like solar cells, photodetectors, lasers and light-emitting diodes [1][2][3][4][5][6][7][8]. Among hybrid semiconductors, the 2D layered hybrid perovskite quantum well materials (C n H 2n+1 NH 3 ) 2 (CH 3 NH 3 ) m-1 Pb m X 3m+1 , (X=Cl, Br, I; m=1, 2...; n=1, 2...) have attracted extensive attention, because the well width and the barrier width can be changed by altering m and n, respectively [9][10][11][12]. This layered structure is packed by one or more sheets of cornershared PbX 6 octahedra and bilayers of organic cations alternating along the c axis [3].…”

“…This layered structure is packed by one or more sheets of cornershared PbX 6 octahedra and bilayers of organic cations alternating along the c axis [3]. The excitons within the octahedral planes are isolated by the organic layers which act as a dielectric spacer forming confining layers, leading to high oscillator strengths, high exciton binding energies, and fast radiative decay rates [8,9,13,14]. These features are highly beneficial to the applications in the field of lighting and displays.…”

Polymorphic Pure Organic Luminogens with Through‐Space Conjugation and Persistent Room‐Temperature Phosphorescence

“…So far,r esearchers have tried to promote the spin-orbit coupling (SOC) and subsequent intersystem crossing( ISC) through incorporation of carbonyl groups (C=O), halogens, and heteroatoms. [17,[20][21][22]31] At the same time, several other approaches, including radical-ion pairs, [32] s-n conjugation, [33] crystallization, [24,[34][35][36][37] embeddingi n ar igid matrix, [9,[38][39][40] Ha ggregation, [8,31,41] metal-organic frameworks or organic-inorganic perovskites, [42][43][44] have been proposed to stabilize the triplet excitons as am eans to achieve efficient p-RTP luminogens.…”