Electrically conducting amorphous molecular material: Iodine doped m-MTDATA as a hole injection buffer layer in organic electroluminescent devices

摘要

An electrically conducting amorphous molecular material was prepared by iodine doping of 4,4',40"-tris[3-methylphenyl(phenyl)amino]triphenylamine(m-MTDATA). The use of iodine-doped m-MTDATA, which was identified as m-MTDATA radical cation species with counter anions, as a hole-injection buffer layer in tris(8-quinolinolato) aluminum (Alq(3))-based organic electroluminescent devices led to the reduction of drive voltage and the enhancement of external quantum efficiency as compared with the corresponding device using undoped m-MTDATA. It is indicated that the use of iodine-doped m-MTDATA facilitates not only hole injection from the ITO electrode but also electron injection from the cathode into Alq(3).