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 PLmax values in the range of 439–445 nm. MAM, MAT, and TAT all have high Tg values above 120 °C; TAT has the highest Tg 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.
We describe two novel blue emission materials based on a new type of dual core concept. 1-Phenyl-6-(10-phenyl-anthracen-9-yl)-pyrene (Ph-AP-Ph) and 1-[1,1′;3′,1′′]terphenyl-5′-yl-6-(10-[1,1′;3′,1′′]terphenyl-5′-yl-anthracen-9-yl)-pyrene (TP-AP-TP) were synthesized through boronylation and Suzuki coupling reactions. The Tg values of Ph-AP-Ph and TP-AP-TP were 228 °C and 243 °C, respectively, compared to values of 135 °C and 139 °C for the single core materials 9-(3′,5′-diphenylphenyl)-10-(3′′′,5′′′-diphenylbiphenyl-4′′-yl)anthracene (MAM) and 1,6-bis-[1,1′;3′,1′′]terphenyl-5′-yl-pyrene (TP-P-TP). One of the dual core derivatives, TP-AP-TP, exhibited an ELmax value of 456 nm and a high luminance EQE of 7.51% when used in an EL device. The dual core chromophore materials had narrower PL and EL spectra and better thermal properties than the single core chromophore materials. A device based on TP-AP-TP showed twice the lifetime of a device based on the commercialized material, 2-methyl-9,10-bis(naphthalen-2-yl)anthracene (MADN).