Highly efficient blue OLED

Abstract

Based on our work on deep blue OLED, very recently, we have synthesized a deep blue emitter TPEA. The anthracene groups are twisted from the central TPE moiety, which effectively prevents bathochromic shift of emission as shown in its crystallographic structure. In addition, a D-A structure was built by using methoxy and cyano to improve the charge balance in the devices. In addition, the material possesses high thermal stability with a Tg of 155 °C. The non-doped device achieved the high performance with a Von of 2.6 V at a luminance of 1 cd rrr2, a 77PE, max Of 11.1 lm W~1, a TJCE, max of 9.9 cd A '1, and a low 77ce roll-off. The doped device based on TPEA was fabricated to acquire deep blue emission with CIE coordinates of (0.15, 0.09), showing a tje x t, max up to 8.0% and the highest t j p e, max of 7.3 lm W"1 among all the TTF and HLCT deep-blue emitters. Inspired by these preliminary results, we believe that the combination of the merits of TTF-HLCT and AIE would be a promising molecular design principle for exploring highly efficient deep blue emitters.