Facile Preparation of Light Emitting Organic Metal Halide Crystals with Near-Unity Quantum Efficiency

Abstract

We report the synthesis and characterization of (Ph 4 P) 2 SbCl 5 , a novel ionically bonded organic metal halide hybrid with a zero-dimensional (0D) structure at the molecular level. By cocrystallization of tetraphenylphosphonium (Ph 4 P + ) and antimony (Sb 3+ ) chloride salts, (Ph 4 P) 2 SbCl 5 bulk single crystals can be prepared in high yield, which exhibit a highly efficient broadband red emission peaked at 648 nm with a photoluminescence quantum efficiency (PLQE) of around 87%. Density functional theory (DFT) calculations reveal the origin of emission as phosphorescence from the excitons localized at SbCl 5 2− with strong excited-state structural distortion. Interestingly, (Ph 4 P) 2 SbCl 5 bulk crystals with a PLQE of around 100% can be prepared via a rapid crystal growth process within minutes, followed by a spontaneous structural transformation. It was found that the rapid growth process yielded a yellow emitting kinetically favored metastable product containing solvent molecules, which turned into the red emitting thermodynamically stable product slowly at room temperature or quickly upon thermal treatment.

Organic–inorganic metal halide hybrids beyond perovskites

“…Highly luminescent 0D Sb halide hybrids, such as [Bmim] 2 SbCl 5 [132] and (C 9 NH 20 ) 2 SbCl 5 [14], have been reported, which contain isolated pyramidal SbCl 5 species. Recently, a facile synthetic approach was established to prepare 0D (Ph 4 P) 2 SbCl 5 by taking advantage of the easy crystallization of tetraphenylphosphonium salts (Figure 8(g)) [133]. With the same organic cation, a green emitting 0D hybrid containing tetrahedral MnBr 4 species was developed by Xu et al, which was used as solution processable emitter in OLEDs.…”

Impact of metal ns2 lone pair on luminescence quantum efficiency in low-dimensional halide perovskites

“…Previous PBE0 calculations have shown accurate results in exciton excitation and emission energies in hybrid organic-inorganic halide perovskites. [22,24,32,33] Spin-orbit coupling (SOC) was included in the calculations on Cs4PbBr6 because it was shown previously that the SOC has a strong effect on Pb-6p-derived conduction band. [34] Following the Franck-Condon principle, the exciton excitation and emission energies were obtained by calculating the total energy differences between the excited and the ground states using PBE0-optimized ground-state and excited-state structures, respectively.…”

“…Low-dimensional hybrid and all-inorganic halide perovskites have recently attracted intense interests for their novel luminescent properties. [19,20] High PLQE has been reported in many 0D hybrid organic-inorganic halide perovskites, [21][22][23] owing to the radiative recombination of strongly self-trapped excitons (STEs). For example, (C4N2H14X)4SnBr6 exhibits near-unity PLQE.…”

Hybrid Chloroantimonates(III): Thermally Induced Triple‐Mode Reversible Luminescent Switching and Laser‐Printable Rewritable Luminescent Paper

“…For 2,ared light peaked at 600 nm was emitted when excited by 396 nm UV light ( Figure 1d). [11,12] TheP Lq uantum yield (PLQE) of 1 is measured as 87.5 %(l ex = 365 nm, l em = 525 nm) with al ifetime of 2.4 ms. [11,12] TheP Lq uantum yield (PLQE) of 1 is measured as 87.5 %(l ex = 365 nm, l em = 525 nm) with al ifetime of 2.4 ms.…”

“…Thee missions can be attributed to the XMCT [10b, 11] of [SbCl n ] 3Àn .T he emission color difference of 1 and 2 can be attributed to the secondorder Jahn-Teller effect that stabilizes the [SbCl 5 ] 2À or [SbCl 4 ] À complexes due to the presence of stereochemically active s 2 lone-pair electrons.T he resultant distortion in coordination geometry of Sb 3+ in [SbCl 5 ] 2À caused aP Lr edshift compared with that of [SbCl 6 ] 3À . [11,12] TheP Lq uantum yield (PLQE) of 1 is measured as 87.5 %(l ex = 365 nm, l em = 525 nm) with al ifetime of 2.4 ms. While for 2,t he PLQE is 22.3 %(l ex = 375 nm, l em = 600 nm), and the lifetime is 2.6 ms.…”