Sb³⁺‐Doping in Cesium Zinc Halides Single Crystals Enabling High‐Efficiency Near‐Infrared Emission

Abstract

Luminescent metal halide materials with flexible crystallography/electronic structures and tunable emission have demonstrated broad application prospects in the visible light region. However, designing near‐infrared (NIR) light‐emitting metal halides remains a challenge. Here, an enlightening prototype is proposed to explore the high‐efficiency broadband NIR emission in metal halide systems by incorporating Sb3+ into the Cs2ZnCl4 matrix. Combined experimental analysis and density functional theory calculations reveal a modified self‐trapped excitons model to elaborate the NIR emission. The high photoluminescence quantum yield of 69.9% peaking at 745 nm and large full width at half maximum of 175 nm, along with excellent air/thermal stability, show the unique advantages of lead‐free metal halide Cs2ZnCl4:Sb3+ as the NIR light source. The substitution of Cl− by Br− further enables the red‐shift of emission peak from 745 to 823 nm. The NIR light‐emitting diode device based on Cs2ZnCl4:Sb3+ demonstrates potential as a non‐visible light source in night vision. This study puts forward an effective strategy to design the novel eco‐friendly and high‐efficiency NIR emissive materials and provides guidance for expanding the application scope of luminescent metal halides.

Ultrafast Study of Exciton Transfer in Sb(III)-Doped Two-Dimensional [NH3(CH2)4NH3]CdBr4 Perovskite

“…As for Sb 3+ -doped Cd-PVK, we first adopt the model that a Sb 3+ ion substitutes one Cd 2+ ion concurrent with the losing of one proton of butanediammonium closest to the replaced Cd 2+ site (Figure 4a) because of the highest possibility of this replacing mode reported by a similar work. 52 Consistent with previous results, 36 Cd-PVK exhibits an indirect bandgap with a value of ∼2.83 eV (Figure S13). Upon introducing Sb 3+ , a new 5s-related energy levels near the VBM and 5p-related energy levels below the CBM is observed (Figure 4b), agreeing well with the projected density of states (PDOS) (Figure 4c) and previous results.…”

“…To help understand the different effects of doping between Sb 3+ and Pb 2+ , density function theory (DFT) calculations were conducted (the computational methodology is described in the Supporting Information). As for Sb 3+ -doped Cd-PVK, we first adopt the model that a Sb 3+ ion substitutes one Cd 2+ ion concurrent with the losing of one proton of butanediammonium closest to the replaced Cd 2+ site (Figure a) because of the highest possibility of this replacing mode reported by a similar work …”

Cyan Emission in Two-Dimensional Colloidal Cs2CdCl4:Sb3+Ruddlesden–Popper Phase Nanoplatelets

“…The photoluminescence excitation (PLE) spectrum consists of two different bands around 290 and 340 nm (Figure a). Typically, Sb 3+ possesses an allowed 1 S 0 – 1 P 1 and a partially allowed 1 S 0 – 3 P 1 transition named C and A bands, respectively, − which reportedly split into a triplet and a doublet due to a pseudo-Jahn–Teller effect. ,, The PLE spectrum of Cs 2 CdCl 4 :Sb 3+ follows this predicted behavior, with the A band evidenced by the features at ∼350 and 333 nm and the C band evidenced by the signals at 293 and ∼280 nm (Figure S9), mostly resembling the bulk material . The third peak of the triplet, which is expected to be around 270 nm, might be partially shadowed by other features.…”

Zero‐Dimensional Organic Copper(I) Iodide Hybrid with High Anti‐Water Stability for Blue‐Light‐Excitable Solid‐State Lighting

“…[7][8][9][10][11][12][13][14] Up to now, many 0D luminescence materials with broad-band emission have been explored to replace the rare earth phosphors for LED applications. [15][16][17][18][19][20][21][22] However, the high water solubility of inorganic metal salts and organic ammonium salts makes them show poor water stability. On the other hand, in commercial LED chips, blue LED chip shows the high efficiency, however, most 0D metal halides have poor blue light absorption due to the large band gaps.…”