Exceedingly efficient deep-blue electroluminescence from new anthracenes obtained using rational molecular design

Abstract

9,10-Bis(3′,5′-diphenylphenyl)anthracene [MAM], 9-(3′,5′-diphenylphenyl)-10-(3‴,5‴-diphenylbiphenyl-4″-yl)anthracene [MAT], and 9,10-bis(3″,5″-diphenylbiphenyl-4′-yl)anthracene [TAT] were newly synthesized through boration and Suzuki aryl–aryl coupling reactions. We have demonstrated that the EL performance of blue-light emitters can be optimized and improved by varying the chemical structures of the side groups. In the thin film state, the three materials exhibit PL_max values in the range of 439–445 nm. MAM, MAT, and TAT all have high T_g values above 120 °C; TAT has the highest T_g value, above 150 °C. This is twice as high as that of DPVBi (64 °C) and is much higher than that of MADN (120 °C) as well. It also exhibits excellent color coordinates (0.156, 0.088), which are very close to the NTSC blue standard, and an external quantum efficiency of 7.18%, twice that of MADN, which are the best reported results for deep-blue OLED emitters.