Antimony-based metal halide hybrids have attracted enormous attention due to the stereoactive 5s² electron pair that drives intense triplet broadband emission. However, energy/charge transfer has been rarely achieved for Sb³⁺-doped materials. Herein, Sb³⁺ ions are homogeneously doped into 2D [NH₃(CH₂)₄NH₃]CdBr₄ perovskite (Cd-PVK) using a wet-chemical method. Compared to the weak singlet exciton emission of Cd-PVK at 380 nm, 0.01% Sb³⁺-doped Cd-PVK exhibits intense triplet emission located at 640 nm with a near-unity quantum yield. Further increasing the doping concentration of Sb³⁺ completely quenches singlet exciton emission of Cd-PVK, concurrently with enhanced Sb³⁺ triplet emission. Delayed luminescence and femtosecond-transient absorption studies suggest that Sb³⁺ emission originates from exciton transfer (ET) from Cd-PVK host to Sb³⁺ dopant, while such ET cannot occur with Pb²⁺-doped Cd-PVK because of the mismatch of energy levels. In addition, density function theory calculations indicate that the introduced Sb³⁺ likely replace the Cd²⁺ ions along with the deprotonation of butanediammonium for charge balance, instead of generating Cd²⁺ vacancies. This work provides a deeper understanding of the ET of Sb³⁺-doped Cd-PVK and suggests an effective strategy to achieve efficient triplet Sb³⁺ emission beyond 0D Cl-based hybrids.

中文翻译：

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Sb(III)掺杂二维[NH3(CH2)4NH3]CdBr4钙钛矿中激子转移的超快研究

由于具有立体活性的 5s ²电子对驱动强烈的三线态宽带发射，基于锑的金属卤化物杂化物引起了极大的关注。然而，Sb ³⁺掺杂材料很少实现能量/电荷转移。在此，使用湿化学方法将Sb ³⁺离子均匀掺杂到 2D [NH ₃ (CH ₂ ) ₄ NH ₃ ]CdBr ₄钙钛矿 (Cd-PVK) 中。与 Cd-PVK 在 380 nm 处的弱单线态激子发射相比，0.01% Sb ³⁺掺杂的 Cd-PVK 在 640 nm 处表现出强烈的三线态发射，量子产率接近统一。进一步提高 Sb ³⁺的掺杂浓度完全淬灭 Cd-PVK 的单线态激子发射，同时增强 Sb ³⁺三线态发射。延迟发光和飞秒瞬态吸收研究表明 Sb ³⁺发射源于从 Cd-PVK 主体到 Sb ³⁺掺杂剂的激子转移 (ET) ，而这种 ET 不会发生在 Pb ²⁺掺杂的 Cd-PVK 中，因为不匹配的能量水平。此外，密度函数理论计算表明，引入的 Sb ³⁺可能取代 Cd ²⁺离子以及丁二铵去质子化以实现电荷平衡，而不是产生 Cd ²⁺空位。这项工作提供了对 Sb ³⁺ ET 的更深入理解掺杂的 Cd-PVK 并提出了一种有效的策略，以实现超越 0D Cl 基杂化体的高效三重态 Sb ³⁺发射。