New blue emitters including phenanthro[9,10-d]oxazole and bulky side group

The new blue organic emitter materials, 4'-(3-(phenanthro[9,10-d]oxazol-2-yl -)phenyl)-5'-phenyl-1[1,1',:2',1''-tetraphenyl]-4-carbonitrile (m-PO-PPCN) and 4'-(4-(phenanthro[9,10-d]oxazol-2-yl-)phenyl)-5'-phenyl-1[1,1',:2',1''-tetraphenyl]-4- carbonitrile (p-PO-PPCN) have been successfully synthesized and characterized. In the film state, the ultraviolet-visible (UV-Vis) absorption peaks of m-PO-PPCN and p-PO-PPCN were 402 and 413 nm, and the photoluminescence (PL) peaks were 408 and 457 nm. The photoluminescence quantum yield (PLQY) of the two materials was 38.4% and 54.9%. Organic light emitting diodes using m-PO-PPCN and p-PO-PPCN as the emitting layer (EML) showed that m-PO-PPCN had a current efficiency of 0.97 cd/A and an EQE of 1.25%, p-PO-PPCN exhibited current efficiency of 3.69 cd/A and an EQE of 3.46%.