A Silole‐Based Efficient Electroluminescent Material with Good Electron‐Transporting Potential

Abstract A new silole derivative, 2,5‐bis(7‐(dimesitylboranyl)‐9,9‐dimethylfluoren‐2‐yl)‐1‐methyl‐1,3,4‐triphenylsilole ((MesBF) 2 MTPS), is synthesized and characterized. (MesBF) 2 MTPS shows a good fluorescence efficiency of 15% in THF solution and a higher efficiency of 86% in solid film, presenting an aggregation‐enhanced emission characteristic. It is thermally and morphologically stable, with high decomposition and glass‐transition temperatures of 257 and 171°C, respectively. The LUMO energy level (−2.96 eV) of (MesBF) 2 MTPS is lower than that of TPBi, revealing its electron‐transporting potential. Efficient organic light‐emitting diodes (OLEDs) are fabricated using (MesBF) 2 MTPS as emitter, which radiates yellow light at 554 nm, and affords high maximum luminance, current efficiency, and external quantum efficiency of 48348 cd·m −2 , 12.3 cd·A −1 , and 4.1%, respectively.