Halogen Substitution in Zero‐Dimensional Mixed Metal Halides toward Photoluminescence Modulation and Enhanced Quantum Yield

Abstract

Zero‐dimensional (0D) organic−inorganic hybrid metal halides haveunprecedented degrees of freedom for structural tunability and photoluminescence modulation. Here, the 0D isomorphic hybrid metal mixed halides (C9NH20)9Pb3Zn2Br19(1−x)Cl19x (x = 0–1) with continuous halogen contents control, exhibiting tunable emission and enhancement of photoluminescence quantum yield (PLQY) are reported. The competitive bromine to chlorine substitution process in (C9NH20)9Pb3Zn2Br19(1−x)Cl19x occurs first in [ZnBr4−xClx]2− tetrahedron before the [Pb3Br11−xClx]5− trimer. The increasing Cl content in samples from x = 0 to 1 results in an expected blue shift of emission peak from 565 to 516 nm, and meanwhile a strikingly room temperature PL quantum yield increase from 8% to 91%. Combined experimental characterizations and theoretical calculations indicate that the blue shift of interband transition energy is responsible for the emission peak shift. Moreover, with the increasing Cl content, the enhanced electron−phonon interaction and the weakened thermal‐assisted nonradiative recombination result in more efficient radiative transition channels and ultimately enhanced PLQY. The impact of halogen substitution on electronic structures and optical properties in 0D hybrid metal halides is emphasized in this work as a new strategy to promote the future development of new luminescent materials.

Pressure‐Engineered Photoluminescence Tuning in Zero‐Dimensional Lead Bromide Trimer Clusters

“…As previously mentioned, the structure of [Pb 3 Br 11 ] 5− clusters determines the optical properties of (bmpy) 9 [ZnBr 4 ] 2 [Pb 3 Br 11 ] [11] . Upon compression to 7.2 GPa, the Pb‐Br bonds in [Pb 3 Br 11 ] 5− clusters are continuously contracted (Figure S14).…”

Controlled Structural Transformation in Sb‐Doped Indium Halides A3InCl6 and A2InCl5∙H2O Yields Reversible Green‐to‐Yellow Emission Switch

“…[ 13 ] Other related 0D indium halide perovskites have shown rich structures and physical and chemical properties. [ 14 ] For example, Cs 2 InBr 5 ·H 2 O displayed a red emission with a PLQY of 33% and a yellow emission after heating to dehydrate the material, exhibiting the unique property of a sensitive water detection. [ 15 ] Prior to the current work, there have been only a few reports on the synthesis of A 2 InCl 5 ∙H 2 O and A 3 InCl 6 (A = Rb + , Cs + ) using HCl or MeOH as the reaction solvent.…”

Regulation of structures and optical properties inlow-dimensional metal halides: Chemical synthesisand physical high-pressure

“…四面体结构导致的(图2(f)) [22] . 此外, 四面体构型的0D 子的相对能级位置 [21,29] . 例如, 通过改变CsPbX 3 (I, Br, Cl)卤素的比例, 可以引起其荧光峰在光谱范围内 (410~700 nm)的明显变化.…”

“…另外, 卤族元素的替换还能够提高 低维金属卤化物的荧光量子产率. 夏志国课题组 [21] 在 ; (e) (C 9 NH 20 ) 2 SnBr 4 的晶体结构示意图 [22] ; (f) 在激发态, 由结构扭曲引起的Stokes位移坐标图; (g) 有机-无机杂化的(Cat) 2 MnX 4 结构示意图 [23] ; (h) (Bz(Me) 3 N) 2 MnCl 4 的荧光激发光谱和荧光发射光谱 [23] ; ; (e) the crystal structure of (C 9 NH 20 ) 2 SnBr 4 [22] ; (f) the configuration coordinate diagram for the excited-state structural-deformation-induced large Stokes shift [22] ; (g) the structure of organic-inorganic hybrids (Cat) 2 MnX 4 [23] ; (h) excitation and emission spectra of (Bz(Me) 3 N) 2 MnCl 4 [23] ; ; (j) excitation dependent PL spectra at room temperature. The excitation wavelength is adjusted from 320 to 380 nm [24] ; crystal structure (k) and absorption, excitation, and emission spectra of (HMTA) 4 PbMn 0.69 Sn 0.31 Br 8 (l) [25] 使非铅全无机0D金属卤化物A 3 InCl 6 (A = Rb, Cs)的量 子产率从<2%增加到85%~95% [35] .…”