Thermally Activated Long Persistent Luminescence of Organic Inorganic Metal Halides

Abstract

Long persistent luminescence (LPL) materials of SrAl 2 O 4 doped with Eu 2 + or Dy 3 + can maintain emission over hours after ceasing the excitation but suffer from insolubility, high cost, and harsh preparation. Recently, organic LPL of guest-host exciplex systems has been demonstrated via an intermediate charge-separated state with flexible design but poor airstability. Here, we synthesized a nontoxic two-dimensional organic-inorganic metal hybrid halides (OIMHs), called PBA 2 [ZnX 4 ] with X = Br or Cl and PBA = 4phenylbenzylamine. These materials exhibit stable LPL emission over minutes at room-temperature, which is two orders of magnitude longer than those of previously reported OIMHs. The mechanism study shows that the LPL emission comes from thermally activated charge separation state rather than room-temperature phosphorescence. Moreover, the LPL of PBA 2 [ZnX 4 ] can be excited by low power sources, representing an effective strategy for developing low-cost and high-stability LPL systems.

High-efficiency color-tunable ultralong room-temperature phosphorescence from organic–inorganic metal halides via synergistic inter/intramolecular interactions

“…Low-dimensional organic-inorganic metal-halide hybrids have shown excellent optoelectronic properties in applications like solar cells and photoemission devices. [15][16][17][18][19][20][21][22][23][24][25][26] For example, zerodimensional (0D) metal halides assembled by inorganic metal-halide units (anion group) and organic cations at the molecular level can promote excitedstate carriers localized within the inorganic units, thereby resulting in effective radiative recombination. 27 Generally, versatile structures and intermolecular interactions can be achieved for 0D metal-halide hybrids by selecting the metal, halogen and organic components, which provides suitable platforms to design materials with tunable optical properties.…”

Mapping the Space of Inorganic and Hybrid Halides and Their Optical Properties Using Mechanochemistry and First-Principles Calculations

“…All inorganic and organic–inorganic hybrid metal halides (MHs) have recently emerged as one of the efficient optical materials for lighting applications. − These families of materials are reported decades before, and extensive research has been carried out to establish their formation chemistry. However, the self-trap emission (STE) having high photoluminescence (PL) quantum yields and even with near unity in some cases took these in frontline in current research. ,− Hence, during the last 5 years, these have been emerged as new-generation optoelectronic materials with important potentials in light-emitting diodes, nonlinear optics, scintillators, and solar cells. − These optically active metal halides mostly contain group IA metal ions or organic cations (A), other metal ions (B), and the halide (X) ions Cl–, Br–, or I–.…”

Zero‐Dimensional Organic–Inorganic Hybrid Zinc Halides for Multiple Applications in Anti‐Counterfeiting, X‐Ray Imaging and White LEDs

“…[34][35][36][37] It is worth noting that replacing toxic Pb 2+ with "green" Zn 2+ significantly reduces the harm to the environment and humans. [38][39][40] For example, based on the compositional engineering strategy, Zhou and co-workers prepared several zinc metal halide: A 2 ZnX 4 (A = Rb, Cs; X = Cl, Br) with or without Cu-doping and their mixed-halide counterparts (Cs 2 ZnCl x Br 4-x :Cu, x = 0−4), blue emitting Cs 2 ZnBr 4 :Cu with a high photoluminescent quantum yield (PLQY) of 57%. [41] Kuang and co-workers developed a 0D BAPPZn 2 (Cl y Br 1-y ) 8 (BAPP = 1,4-bis(3-ammoniopropyl)piperazinium, y = 0−1) with ultra-long room-temperature phosphorescence, the afterglow lifetime can be facilely tuned by regulating the halideinduced heavy-atom effect and can be identified by the naked eyes or with the help of a simple machine vision system.…”