Dibenzofuran derivatives with meta- and para-triphenylamine substituents as hole-transporting materials in organic light-emitting devices

Abstract

Three novel hole-transporting materials, 3,3'-(dibenzo[b,d]furan-2,8-diyl)bis(N,N-diphenylaniline) (BF-m-TPA), 4,4'-(dibenzo[b,d]furan-2,8-diyl)bis(N,N-diphenylaniline) (BF-p-TPA) and 4,4'-(dibenzo[b,d]furan-2,6-diyl)bis(N,N-diphenylaniline) (BF-2,6-TPA), were designed and synthesized. Owing to the rigid dibenzofuran core, these BF-TPA derivatives exhibited high thermal decomposition temperatures of over 395 °C and very high LUMO energy levels. Electroluminescent (EL) devices were fabricated using these three hole-transporting materials. The best device performance was obtained for BF-m-TPA, with the maximum luminance (L) of 15,230 cd/m2, luminance efficiency (LE) of 56.5 cd/A, power efficiency (PE) of 13.3 lm/W, and external quantum efficiency (EQE) of 16.3%.