Abstract
Organic electroluminescent (EL) devices with a novel hole-injecting layer using Lewis-acid-doped arylamine derivatives were investigated. The hole-injecting layer was fabricated by coevaporation of a Lewis acid, FeCl3, and an arylamine derivative, N,N'-dinaphtyl-N,N-diphenyl bendizine (α-NPD). Optical absorption spectra of the Lewis acid-doped layer indicated that charge transfer (CT) complexes between α-NPD and FeCl3 were formed. Organic EL devices having a structure of ITO/FeCl3-doped α-NPD (1000 Å)/α-NPD (500 Å)/tris(8-quinolinolato)aluminum (III) (Alq3) (700 Å)/LiF (5 Å)/Al exhibited low drive voltages and high luminance of 27000 cd/m2 at 10 V.