Su Binbin, Song Gaomin, Molokeev Maxim S, Lin Zheshuai, Xia Zhiguo
The State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Fiber Laser Materials and Applied Techniques, School of Materials Science and Technology, South China University of Technology, Guangzhou, 510640, P. R. China.
Technical Institute of Physics and Chemistry, University of Chinese Academy of Sciences, Beijing 100190, P. R. China.
Inorg Chem. 2020 Jul 20;59(14):9962-9968. doi: 10.1021/acs.inorgchem.0c01103. Epub 2020 Jul 6.
Organic-inorganic hybrid metal halides with broad-band emission are currently receiving an increasing interest for their unique light emission properties. Here we report a novel lead-free zero-dimensional (0D) tin halide, (CHN)SnBr, in which isolated [SnBr] octahedrons are cocrystallized with organic cations, 1,3-bis(aminomethyl)benzene (CHN). Upon photoexcitation, the bulk crystals exhibit broad-band green emission peaking at 507 nm with a full width at half-maximum (fwhm) of 82 nm (0.395 eV), a Stokes shift of 157 nm (1.09 eV), and a photoluminescence quantum yield (PLQY) of 36 ± 4%. Combined structural analysis and density functional theory (DFT) calculations indicate that the excited state structural distortion of [SnBr] octahedral units account for the formation of this green emission. The relatively small Stokes shift and narrow fwhm of the emission are hence caused by the reduced distortion of [SnBr] octahedrons and rigid molecular structure. The discovery of lead-free (CHN)SnBr and insight into the mechanism of green emission provide an essential platform toward unveiling the relationship between structure and property for 0D metal halide perovskites.
具有宽带发射的有机-无机杂化金属卤化物因其独特的发光特性目前正受到越来越多的关注。在此，我们报道了一种新型的无铅零维（0D）锡卤化物(CHN)SnBr，其中孤立的[SnBr]八面体与有机阳离子1,3-双（氨甲基）苯（CHN）共结晶。光激发时，块状晶体呈现出宽带绿色发射，峰值位于507nm，半高宽（fwhm）为82nm（0.395eV），斯托克斯位移为157nm（1.09eV），光致发光量子产率（PLQY）为36±4%。结合结构分析和密度泛函理论（DFT）计算表明，[SnBr]八面体单元的激发态结构畸变是这种绿色发射形成的原因。发射的相对较小的斯托克斯位移和较窄的半高宽因此是由[SnBr]八面体畸变的减少和刚性分子结构引起的。无铅(CHN)SnBr的发现以及对绿色发射机制的深入了解为揭示0D金属卤化物钙钛矿的结构与性质之间的关系提供了一个重要平台。
