Cyclometalated Pt(II) complexes can show intense phosphorescence at room temperature. Their emission properties are determined by both the organic ligand and the metal center. Whereas most of the related studies focus on tuning the properties by designing different types of organic ligands, only several reports investigate the key role played by the metal center. To address this issue, phosphorescent Pt(II) complexes with one, two, and three Pt(II) centers are designed and synthesized. With more Pt(II) centers, the cyclometalated multinuclear Pt(II) complexes display red-shifted emissions with increased photoluminescence quantum yields. Most importantly, solution-processed organic light-emitting diodes (OLEDs) with the conventional device structure using the multinuclear Pt(II) complexes as emitters show excellent performance. The controlled device based on the conventional mononuclear Pt(II) complex shows a peak external quantum efficiency, current efficiency, and power efficiency of 6.4%, 14.4 cd A^–1, and 12.1 lm W^–1, respectively. The efficiencies are dramatically improved to 10.5%, 21.4 cd A^–1, and 12.9 lm W^–1 for the OLED based on the dinuclear Pt(II) complex and to 17.0%, 35.4 cd A^–1, and 27.2 lm W^–1 for the OLED based on the trinuclear Pt(II) complex, respectively. To the best of our knowledge, these efficiencies are among the highest ever reported for the multinuclear Pt(II) complex-based OLEDs.

中文翻译：

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通过磷光环金属化三核Pt（II）配合物实现高性能溶液处理的橙色OLED

环金属化的Pt（II）配合物在室温下会显示强烈的磷光。它们的发射特性由有机配体和金属中心决定。尽管大多数相关研究集中在通过设计不同类型的有机配体来调节性能，但只有少数报告调查了金属中心所起的关键作用。为了解决这个问题，设计并合成了具有一个，两个和三个Pt（II）中心的磷光Pt（II）配合物。随着更多的Pt（II）中心，环金属化的多核Pt（II）配合物显示出红移发射，并具有增加的光致发光量子产率。最重要的是，具有使用多核Pt（II）配合物作为发射体的常规器件结构的固溶处理有机发光二极管（OLED）显示出出色的性能。^{分别为–1}和12.1 lm W ^–1。对于基于双核Pt（II）配合物的OLED ，效率显着提高到10.5％，21.4 cd A ^–1和12.9 lm W ^–1，并分别提高到17.0％，35.4 cd A ^–1和27.2 lm W ^–1分别用于基于三核Pt（II）配合物的OLED。据我们所知，这些效率是有报道的基于多核Pt（II）配合物的OLED的最高效率。