Deep-blue organic electroluminescence (EL) emitters are important for full-color display and solid-state lighting applications of organic light-emitting diode (OLED) technology. Triplet-triplet annihilation (TTA) is one efficient approach for realizing efficient deep-blue EL. In this study, a PPI donor and a BI acceptor are connected via an anthracene (AN) bridge to obtain a bipolar deep-blue TTA emitter, PPI-AN-BI. The effects of the donor and the acceptor moieties are studied by comparing photophysical properties of molecules obtained by replacing either the PPI or the BI group with a phenyl (P) group to obtain BI-AN-P or PPI-AN-P. Non-doped OLEDs based on the three molecules display high-performance deep-blue EL. Using PPI-AN-BI as a non-doped emitter, a trilayer device exhibits a maximum external quantum efficiency (EQE) of 8.4% with a CIE index of (0.15, 0.15), and a bilayer device exhibits a maximum EQE of 6.9% with a CIE index of (0.15, 0.15). It is experimentally and theoretically demonstrated that triplet pair transition and enhanced oscillator strength can be the main reasons contributing to high performances. This work would provide an efficient method for designing deep-blue non-doped EL emitters.

深蓝色有机电致发光（EL）发射器对于有机发光二极管（OLED）技术的全彩显示和固态照明应用非常重要。三重态三重态an灭（TTA）是实现高效深蓝色EL的一种有效方法。在这项研究中，PPI供体和BI受体通过蒽（AN）桥连接以获得双极深蓝色TTA发射体PPI-AN-BI。通过比较通过用苯基（P）基团取代PPI或BI基团以获得BI-AN-P或PPI-AN-P获得的分子的光物理性质，研究了供体和受体部分的作用。基于这三个分子的非掺杂OLED显示出高性能的深蓝色EL。使用PPI-AN-BI作为非掺杂发射极，三层器件的最大外部量子效率（EQE）为8.4％，CIE指数为（0.15，0.15），双层器件的最大外部量子效率为6.9％，CIE指数为（ 0.15、0.15）。从实验和理论上证明，三重态对跃迁和增强的振荡器强度可能是促成高性能的主要原因。这项工作将为设计深蓝色非掺杂的EL发射器提供一种有效的方法。