Realizing High-Efficiency Yellow Emission of Organic Antimony Halides via Rational Structural Design

Abstract

Zero-dimensional (0D) organic metal halides have captured extensive attention for their various structures and distinguished optical characteristics. However, achieving efficient emission through rational crystal structure design remains a great challenge, and how the crystal structure affects the photophysical properties of 0D metal halides is currently unclear. Herein, a rational crystal structure regulation strategy in 0D Sb­(III)-based metal halides is proposed to realize near-unity photoluminescence quantum yield (PLQY). Specifically, two 0D organic Sb­(III)-based compounds with different coordination configurations, namely, (C25H22P)2SbCl5 and (C25H22P)­SbCl4 (C25H22P+ = benzyltriphenylphosphonium), were successfully obtained by precisely controlling the ratio of the initial raw materials. (C25H22P)2SbCl5 adopts an octahedral coordination geometry and shows highly efficient broadband yellow emission with a PLQY of 98.6%, while (C25H22P)­SbCl4 exhibits a seesaw-shaped [SbCl4]− cluster and does not emit light under photoexcitation. Theoretical calculations reveal that, by rationally controlling the coordination structure, the indirect bandgap of (C25H22P)­SbCl4 can be converted to the direct bandgap of (C25H22P)2SbCl5, thus ultimately boosting the emission intensity. Together with efficient emission and outstanding stability of (C25H22P)2SbCl5, a high-performance white-light emitting diode (WLED) with a high luminous efficiency of 31.2 lm W–1 is demonstrated. Our findings provide a novel strategy to regulate the coordination structure of the crystals, so as to rationally optimize the luminescence properties of organic metal halides.

Cu+@Sb3+-Codoped All-Inorganic Metal Halide of Cs2ZnCl4 with Tunable Dual Emission for Fluorescence Anticounterfeiting and Information Encryption

“…Here, we calculated that the S values of the bands A and B are 14.4 and 25.2, respectively. Obviously, the obtained S values (Figure c) of the two emission bands are comparable to the recently reported lead-free metal halides with an intrinsic broad-band emission (Table S2), − the S of Cs 2 ZnCl 4 : 30%Cu + @20%Sb 3+ similar to other lead-free compounds with STE emission. Therefore, the obtained S value for Cs 2 ZnCl 4 : 30%Cu + @20%Sb 3+ suggests that there is an intense electron–phonon coupling in this compound.…”

“…The exciton binding energy ( E b ) was calculated by eq Here, the values E b of band A and band B of Cs 2 ZnCl 4 : 30%Cu + @20%Sb 3+ are 60 and 61 meV, respectively (Figure S12), which is greater than the thermal disturbance energy at RT (∼26 meV) . This result implies the formation of stable STEs against the thermal decomposition …”

“…54 This result implies the formation of stable STEs against the thermal decomposition. 52 The Raman spectra of Cs 2 ZnCl 4 , 30%Cu + -doped Cs 2 ZnCl 4 , and 30%Cu + @20%Sb 3+ -codoped Cs 2 ZnCl 4 microcrystals were collected at room temperature. As shown in Figure S13, the Raman mode in 50−500 cm −1 is the vibration of the inorganic lattice.…”

Effect of the Host Lattice Environment on the Expression of 5s2 Lone-Pair Electrons in a 0D Bismuth-Based Metal Halide

“…32 shaped [SbCl 4 ] − cluster is nonluminancent at room temperature (RT). 35 Nevertheless, reports relating to the effect of the crystal environment on electron expression are rare, and the understanding of this field is still in its infancy. Therefore, it is very necessary to deeply unveil the relationship between the crystal environment and the expression of 5s 2 lone-pair electrons.…”

“…In addition, the regular octahedral environment has high degeneracy and does not completely separate these energy levels; thus, singlet states remain unobserved. − Similarly, (C 25 H 22 P) 2 SbCl 5 and (C 25 H 22 P)­SbCl 4 (C 25 H 22 P + = benzyltriphenylphosphonium) with different crystal environments and coordination structures exhibit distinct optical characteristics. (C 25 H 22 P) 2 SbCl 5 with an octahedral coordination structure shows highly efficient broad-band yellow emission with a photoluminescence (PL) quantum yield (PLQY) of 98.6%, while (C 25 H 22 P)­SbCl 4 with a seesaw-shaped [SbCl 4 ] − cluster is nonluminancent at room temperature (RT) . Nevertheless, reports relating to the effect of the crystal environment on electron expression are rare, and the understanding of this field is still in its infancy.…”