Singh Kirti, Siddiqui Iram, Sridharan Vidhyalakshmi, Kumar Yadav Rohit Ashok, Jou Jwo-Huei, Adhikari Debashis
Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, SAS Nagar 140306, India.
Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan, Republic of China.
Inorg Chem. 2021 Dec 20;60(24):19128-19135. doi: 10.1021/acs.inorgchem.1c02926. Epub 2021 Dec 5.
Earth-abundant and cheaper zinc-based organometallic molecules as luminophores are drawing significant research attention for solid-state lighting devices. In this paper, we report two air-stable zinc complexes, where the zinc is coordinated to two sterically encumbered β-diketiminate ligands in a tetrahedral geometry. In such a geometry, eight phenyl/aryl rings from the ligand backbones are oriented in a propeller shape, augmenting the restricted rotation of the putative rings. Such an architecture harnesses aggregation-induced emission behavior with an excellent solid-state emission property. The rigidity of these molecules reduces the possibility of non-radiative transitions and makes them excellent fluorescence emitters. Both molecules exhibit electroluminescence (EL) in the yellowish-green region of the visible spectrum. We have utilized these molecules as emitters to fabricate multilayered organic light-emitting diode (OLED) devices. The emitter in host -MTDATA exhibits EL with a maximum external quantum efficiency of 4.4%. Among the handful of zinc-based OLEDs, the performance of this emitter is very commendable with power and current efficacies of 15.2 lm W and 12.1 cd A, respectively, along with a brightness of 2426 cd m.
作为发光体的地球上储量丰富且成本较低的锌基金属有机分子，正吸引着固态照明设备领域的大量研究关注。在本文中，我们报道了两种空气稳定的锌配合物，其中锌以四面体几何构型与两个空间位阻较大的β - 二酮亚胺配体配位。在这种几何构型中，来自配体骨架的八个苯基/芳基环呈螺旋桨形状排列，增加了假定环的受限旋转。这种结构利用了聚集诱导发光行为，具有出色的固态发光性能。这些分子的刚性降低了非辐射跃迁的可能性，使其成为出色的荧光发射体。两种分子在可见光谱的黄绿色区域均表现出电致发光（EL）。我们已将这些分子用作发射体来制造多层有机发光二极管（OLED）器件。主体 - MTDATA中的发射体表现出EL，最大外量子效率为4.4%。在少数几种基于锌的OLED中，该发射体的性能非常值得称赞，功率效率和电流效率分别为15.2 lm/W和12.1 cd/A，亮度为2426 cd/m²。
