Wu Jingjie, Li Xianli, Lian Xin, Su Binbin, Pang Junhong, Li Ming-De, Xia Zhiguo, Zhang Jin Z, Luo Binbin, Huang Xiao-Chun
Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province, Shantou University, Shantou, Guangdong Province, 515063, P. R. China.
School of Materials Science and Engineering, South China University of Technology, Guangzhou, Guangdong Province, 510641, P. R. China.
ACS Nano. 2021 Sep 28;15(9):15354-15361. doi: 10.1021/acsnano.1c06564. Epub 2021 Sep 15.
Antimony-based metal halide hybrids have attracted enormous attention due to the stereoactive 5s electron pair that drives intense triplet broadband emission. However, energy/charge transfer has been rarely achieved for Sb-doped materials. Herein, Sb ions are homogeneously doped into 2D [NH(CH)NH]CdBr perovskite (Cd-PVK) using a wet-chemical method. Compared to the weak singlet exciton emission of Cd-PVK at 380 nm, 0.01% Sb-doped Cd-PVK exhibits intense triplet emission located at 640 nm with a near-unity quantum yield. Further increasing the doping concentration of Sb completely quenches singlet exciton emission of Cd-PVK, concurrently with enhanced Sb triplet emission. Delayed luminescence and femtosecond-transient absorption studies suggest that Sb emission originates from exciton transfer (ET) from Cd-PVK host to Sb dopant, while such ET cannot occur with Pb-doped Cd-PVK because of the mismatch of energy levels. In addition, density function theory calculations indicate that the introduced Sb likely replace the Cd ions along with the deprotonation of butanediammonium for charge balance, instead of generating Cd vacancies. This work provides a deeper understanding of the ET of Sb-doped Cd-PVK and suggests an effective strategy to achieve efficient triplet Sb emission beyond 0D Cl-based hybrids.
基于锑的金属卤化物杂化物因其驱动强烈三重态宽带发射的立体活性5s电子对而备受关注。然而，对于掺锑材料，能量/电荷转移很少实现。在此，采用湿化学方法将锑离子均匀掺杂到二维[NH(CH)NH]CdBr钙钛矿（Cd-PVK）中。与Cd-PVK在380nm处较弱的单重态激子发射相比，0.01%掺锑的Cd-PVK在640nm处表现出强烈的三重态发射，量子产率接近100%。进一步提高锑的掺杂浓度会完全淬灭Cd-PVK的单重态激子发射，同时增强锑的三重态发射。延迟发光和飞秒瞬态吸收研究表明，锑的发射源于激子从Cd-PVK主体转移到锑掺杂剂，而对于掺铅的Cd-PVK，由于能级不匹配，这种激子转移不会发生。此外，密度泛函理论计算表明，引入的锑可能取代Cd离子，同时丁二铵去质子化以实现电荷平衡，而不是产生Cd空位。这项工作为深入理解掺锑Cd-PVK的激子转移提供了依据，并提出了一种有效的策略，以实现超越零维氯基杂化物的高效三重态锑发射。
