Huang Dayu, Ouyang Qiuyun, Wu Jinjiang, Kong Youchao, Wang Bo, Lian Hongzhou, Lin Jun
State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun130022, P. R. China.
Key Laboratory of In-Fiber Integrated Optics, Ministry Education of China, and College of Physics and Opotoelectronic Engineering, Harbin Engineering University, Harbin150001, P. R. China.
Inorg Chem. 2022 Nov 7;61(44):17767-17776. doi: 10.1021/acs.inorgchem.2c03058. Epub 2022 Oct 23.
Broadband emission with a large Stokes shift is important to obtain an excellent color rendering index of the solid-state lighting device. Among low-dimensional material and perovskite-like phosphors with broadband self-trapped emission, Sn-based phosphors have attracted much attention due to their high photoluminescence quantum yield (PLQY). However, the disadvantage is that the synthesis of Sn-based phosphors needs to be performed in a glovebox. Upon photoexcitation, the broadband emission of self-trapped excitons results from exciton-phonon coupling induced by the transient distortion of the lattice. Low-dimensional material structures often promote self-trapped emission because of more vibrational degrees of freedom and easier polarization under photoexcitation. Here, zero-dimensional (0D) SnX (X = Br, I) single crystals are synthesized by the solvent evaporation method in the air. SnX emits blue light, broadband yellow light, and deep red light, among which SnBr has the best luminescence performance. The photoluminescence quantum yield (PLQY) of SnBr reaches 85% and the Stokes shift reaches 265 nm. The PL intensity of SnX is linearly related to excitation power, which preliminarily indicates that the origin of SnX luminescence is attributed to self-trapped emission (STE). The white light-emitting diodes (WLEDs) were fabricated using yellow-emitting SnBr and blue-emitting BaMgAlO:Eu, which has a low correlated color temperature (3160 K) and a relatively common color rendering index (79).
具有大斯托克斯位移的宽带发射对于获得固态照明器件优异的显色指数很重要。在具有宽带自陷发射的低维材料和类钙钛矿磷光体中，锡基磷光体因其高光致发光量子产率（PLQY）而备受关注。然而，缺点是锡基磷光体的合成需要在手套箱中进行。光激发时，自陷激子的宽带发射源于晶格瞬态畸变引起的激子 - 声子耦合。低维材料结构由于具有更多的振动自由度且在光激发下更容易极化，常常促进自陷发射。在此，通过溶剂蒸发法在空气中合成了零维（0D）的SnX（X = Br，I）单晶。SnX发射蓝光、宽带黄光和深红色光，其中SnBr具有最佳的发光性能。SnBr的光致发光量子产率（PLQY）达到85%，斯托克斯位移达到265 nm。SnX的PL强度与激发功率呈线性关系，这初步表明SnX发光的起源归因于自陷发射（STE）。使用发射黄光的SnBr和发射蓝光的BaMgAlO:Eu制备了白光发光二极管（WLED），其具有低相关色温（3160 K）和相对普通的显色指数（79）。
