Diboron complexes with bis-spiro structures as high-performance blue emitters for OLEDs?

Dalton Transactions Pub Date: 2015-07-23 DOI: 10.1039/C5DT02093J

Abstract

To construct high-performance organoboron-based blue emitters for electroluminescent (EL) devices, two diboron complexes have been synthesized through the chelation of 2-(1-phenyl-1H-benzo[d]imidazole-2-yl)phenol or 2-(2-pyridyl)phenol ligands with both boron atoms of the 9,10-diboraanthracene group. These complexes exhibit bright blue emissions in solution and in solid films with fluorescence quantum yields over 0.42, which benefit from their bis-spiro structures. In addition, they possess high thermal decomposition (>410 °C) and glass transition (>163 °C) temperatures. Moreover, they are excellent ambipolar transporting materials with high and balanced mobilities (>10?4 cm2 V?1 s?1) for holes and electrons. Due to these excellent properties, the EL devices adopting these complexes as non-doped emitting layers emit blue light and exhibit low turn-on voltages (<3.2 V), high luminance (up to 9041 cd m?2), as well as high current (up to 7.01 cd A?1) and power efficiencies (up to 7.58 lm W?1). To the best of our knowledge, these devices are so far the brightest and most efficient blue devices based on four-coordinate organoboron emitters.

Graphical abstract: Diboron complexes with bis-spiro structures as high-performance blue emitters for OLEDs
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