Identification of Singlet Self-Trapped Excitons in a New Family of White-Light-Emitting Zero-Dimensional Compounds

Abstract

As illumination is a fundamental human need, the exploration of illumination sources possessing high efficiency and broadband white-light emission is highly desirable. Zero-dimensional (0D) metal halide compounds are promising candidates, and some lead-free antimony-containing compounds exhibit bimodal white-light emissions. However, their origins are still unclear. To solve this issue, we designed and prepared a new family of 0D metal halide compounds consisting of [M(18-crown-6)] + (M = NH 4 , Rb) and SbX 5 2− (X = Cl, Br) units. We found that the emission profiles of 0D compounds are distinct to and well separated from that of 18-crown-6 ether, excluding the intraligand charge transfer mechanism proposed in several reports. Femtosecond transient absorption data and the compositional dependence of photophysical properties imply that bimodal white-light emission is induced by both singlet state and triplet state of the self-trapped excitons ( 1 STE and 3 STE) coupled to metal halides. These 0D compounds are also very efficient emitters, with a white-light photoluminescence quantum yield as high as 54%.

Modulating photoelectron localization degree to achieve controllable photoluminescence quenching and activation of 0D hybrid antimony perovskites

“…3b). 42–44 To reveal the photophysical process, time-resolved PL spectrum monitoring at 610 nm was performed and fitted by a biexponential function giving an average lifetime of 5.078 μs and 5.978 μs at 300 K and 80 K, respectively (Fig. 3c).…”

Nearly one-fold enhancement in photoluminescence quantum yield for isostructural zero-dimensional hybrid antimony(iii) bromides by supramolecular interaction adjustments

“…The Sb–Br bond lengths range from 2.5174(8) to 2.7770(5) Å and 2.5196(7) to 2.7754(5) Å for 1·EtOH-Br and 1·MeCN-Br , respectively (Table S2†), comparable with those of previously reported 0D antimony( iii ) bromides. 26,28,30,31,51…”

Emerging new‐generation white light‐emitting diodes based on luminescent lead‐free halide perovskites and perovskite derivatives

“…Analogous to Bi-based perovskites, the trivalent Sb is isoelectronic with divalent Pb cations and possesses similar electronegativity. [64][65][66][67][68][69][70] Therefore, Sb-based halide perovskites are a potential alternative to Pb-based perovskites for light-emitting applications to address the toxicity and environmental stability issues. [71,72] For instance, two organic-inorganic Sb-based halides with specific forms of (TTA) 2 SbCl 5 (TTA = tetraethylammonium) and [53] Copyright 2017, Wiley-VCH.…”

“…Similarly, Xu et al reported an intense white-light emission with CIE coordinates of (0.43, 0.34) from organic-inorganic hybrid (C 12 H 24 O 6 ) 2 SbCl 5 powders. [67] Considering the volatile nature of organic chains under harsh conditions, more attempts have been implemented to use inorganic cations to realize more stable materials. [68] Zhang et al reported for the first time the synthesis and optical properties of all-inorganic Cs 3 Sb 2 X 9 QDs (X = Cl, Br, I) by a modified ligand-assisted reprecipitation strategy.…”