All-Inorganic Zero-Dimensional Sn-Doped Rb₄CdCl₆ with Near-Unity Quantum Efficiency

Abstract

Zero-dimensional (0D) metal halide perovskites (MHPs) have attracted much attention due to their unique crystal and electronic structure. Drastically different from three-dimensional (3D) CsPbCl 3 analogues, 0D perovskites exhibit broadband emission spectra of self-trapped excitons (STEs) with a large Stokes shift and high exciton binding energy. However, their luminescent efficiencies are much lower than those of the 3D ones. Herein, for the first time, we successfully synthesized the Sn 2+ -doped 0D Rb 4 CdCl 6 with an emission at 485 nm by a simple hydrothermal method. Importantly, the host with a doping of 0.239 Sn shows a near-unity quantum efficiency (PLQY ∼98.04%) under UV light excitation, which is the highest among Cd-based all-inorganic MHPs. The results from temperature-dependent PL spectra suggested that the emission might originate from STEs, where this broad emission is attributed to the 3 P 1 to 1 S 0 radiation transition of octahedral [SnCl 6 ] 4− units in the host matrix. As a result, the as-prepared doped crystals exhibit large Stokes shifts and high quantum efficiency. Our work successfully elucidates that the Sn 2+ dopant plays an integral role in improving PLQY of 0D MHPs. This kind of Sn 2+ -doped promising luminescent materials may have significant applications in optoelectronic devices.

Tunable Emission of Pb(II) and Sb(III) Codoped 2D Hybrid BDACdBr4 Metal Halides for Cryptographic Anticounterfeiting Applications

“…22−25 Meng and Yao et al successfully incorporated Sb 3+ and Sn 2+ with ns 2 electron configuration into Rb−Cdbased halides, respectively, leading to efficient self-trapped exciton (STE) emission. 26,27 Notably, Sb 3+ -doped RbCdCl 3 demonstrates dual-channel emission with singlet 1 P 1 → 1 S 0 (464 nm) and triplet 3 P 1 → 1 S 0 (600 nm) at low temperatures, achieving a remarkable PL quantum yield (PLQY) of approximately 91.7% at room temperature. 26 In the case of Sn 2+ -doped 0D Rb 4 CdCl 6 , high-efficiency sky blue emission at 485 nm with a near-unity PLQY (∼98.04%) is achieved, expanding the potential of Cd-based halides in blue device applications.…”

“…26 In the case of Sn 2+ -doped 0D Rb 4 CdCl 6 , high-efficiency sky blue emission at 485 nm with a near-unity PLQY (∼98.04%) is achieved, expanding the potential of Cd-based halides in blue device applications. 27 The substitution of Cs + cations with organic cations enables the regulation of the dimensionality of metal halides, leading to the formation of hybridized low-dimensional (1D or 2D) structures with enhanced carrier dynamics, which is advantageous for device applications. 28 Wang et al prepared Mn 2+ -doped hybrid 2D (C 6 H 8 N) 2 CdCl 4 (C 6 H 8 N, aniline) by a simple recrystallization method, achieving an impressive 200% red light PLQY with long afterglow properties.…”

“…Recent studies have extensively investigated the photophysical mechanism and optical performances of Cd-based metal halides. – Undoped Cd-based halides, characterized by indirect band gap, generally exhibit poor photoluminescence (PL) properties due to their low probability of radiative recombination between electrons and holes. However, the introduction of transition-metal ions or ions with ns 2 electron configuration as dopants can significantly enhance the PL through efficient energy transfer within the host-dopant system. – Meng and Yao et al successfully incorporated Sb 3+ and Sn 2+ with ns 2 electron configuration into Rb–Cd-based halides, respectively, leading to efficient self-trapped exciton (STE) emission. , Notably, Sb 3+ -doped RbCdCl 3 demonstrates dual-channel emission with singlet 1 P 1 → 1 S 0 (464 nm) and triplet 3 P 1 → 1 S 0 (600 nm) at low temperatures, achieving a remarkable PL quantum yield (PLQY) of approximately 91.7% at room temperature . In the case of Sn 2+ -doped 0D Rb 4 CdCl 6 , high-efficiency sky blue emission at 485 nm with a near-unity PLQY (∼98.04%) is achieved, expanding the potential of Cd-based halides in blue device applications .…”

“…However, the introduction of transition-metal ions or ions with ns 2 electron configuration as dopants can significantly enhance the PL through efficient energy transfer within the host-dopant system. – Meng and Yao et al successfully incorporated Sb 3+ and Sn 2+ with ns 2 electron configuration into Rb–Cd-based halides, respectively, leading to efficient self-trapped exciton (STE) emission. , Notably, Sb 3+ -doped RbCdCl 3 demonstrates dual-channel emission with singlet 1 P 1 → 1 S 0 (464 nm) and triplet 3 P 1 → 1 S 0 (600 nm) at low temperatures, achieving a remarkable PL quantum yield (PLQY) of approximately 91.7% at room temperature . In the case of Sn 2+ -doped 0D Rb 4 CdCl 6 , high-efficiency sky blue emission at 485 nm with a near-unity PLQY (∼98.04%) is achieved, expanding the potential of Cd-based halides in blue device applications . The substitution of Cs + cations with organic cations enables the regulation of the dimensionality of metal halides, leading to the formation of hybridized low-dimensional (1D or 2D) structures with enhanced carrier dynamics, which is advantageous for device applications .…”

Enhancing Luminescence in Hue-Tunable White-Light Emitting K4CdCl6:Sb3+,Mn2+ All-Inorganic Halide Perovskites: Insights from Defect Engineering and Energy Transfer

“…The AIHPs with high chemical and thermal stabilities, excellent optical properties, low-cost synthesis, and tunable bandgap have promising applications in luminescence tagging, imaging, and medical diagnostics in optoelectronic region. − The Cd-based AIHPs and their derivatives have recently received significant attention due to their various structures and composition-dependent luminescence. − The derivatives of Cd-based AIHPs make it possible to achieve multiple functional materials with the desired optoelectronic properties. The Cd-based AIHPs materials, including 3D CsCdCl 3 with a direct band gap, 2D Cs 3 Cd 2 Cl 7 and 0D Cs 2 CdCl 4 with indirect band gaps, have been obtained by adjusting the reagent concentrations, temperature, and injection rates .…”