PNNL

Abstract

We report the synthesis, photophysical and organic light-emitting device (OLED) properties of an organic molecular p-dopant 1,3,4,5,7,8-hexafluorotetracyanonaphthoquinodimethane (F6-TNAP). F6-TNAP was obtained in a three step 2 pot synthesis from commercially available octafluoronaphthalene. Doping effect of F6-TNAP was evaluated using films of 1-5% F6-TNAP with N,N'-di-1-naphthyl-N,N'-diphenyl-1,1'-biphenyl-4,4'diamine???-NPD) co-evaporated on quartz. UV-vis analysis of these films showed an absorption peak at 950 nm corresponding to the charge transfer complex resulting from electron transfer from??-NPD to F6-TNAP. Hole only devices using ??NPD as the hole transport layer (HTL) doped with F6-TNAP show greater than 2V decrease in operating voltage compared to the undoped device. A decrease in operating voltage was also demonstrated in blue OLED devices using F6-TNAP doped HTL, with a slight decrease in external quantum efficiency (EQE), thus resulting in a net improvement in power efficiency.