Highly efficient blue OLED based on 9-anthracene-spirobenzofluorene derivatives as host materials

Abstract

A novel spiro[benzo[c]fluorene-7,9′-fluorene](SBFF)-based blue host material, 9-(10-phenylanthracene-9-yl)SBFF (BH-9PA), 9-(10-(naphthalene-1-yl)anthracene-9-yl)SBFF (BH-9NA) and 9-(10-(4-(naphthalene-1-yl)phenyl)anthracene-9-yl)SBFF (BH-9NPA) were successfully prepared by reacting 9-bromo-SBFF (2) with 10-phenylanthracene-9-yl boronic acid, 10-(naphthalene-1-yl)anthracene-9-yl boronic acid and 10-(4-(naphthalene-1-yl)phenyl)anthracene-9-yl boronic acid through the Suzuki reaction, respectively. Bis[4-(di-p-N,N-diphenylamino)styryl]stilbene (DSA-Ph) and N,N-diphenyl-N′,N′-dim-tolyl-SBFF-5,9-diamine (BD-6MDPA) were used as dopant materials. Blue OLEDs with the configuration ITO/DNTPD/NPB/host : 5% dopant/Alq₃/Al-LiF were prepared from the three host materials doped with DSA-Ph and BD-6MDPA dopants and the device composed of BH-9PA doped with DSA-Ph and BD-6MDPA showed blue EL spectra at 468 and 464 nm at 7 V and luminance efficiencies of 7.03 and 6.60 cd A⁻¹, respectively.