Electron transport in naphthylamine-based organic compounds

Two naphthylamine-based hole transporters, namely, N,N′-diphenyl-N,N′-bis(1-naphthyl)(1,1′-biphenyl)-4,4′diamine (NPB) and 4,4′,4″-tris(n-(2-naphthyl)-n-phenyl-amino)-triphenylamine (2TNATA), were found to possess electron transporting (ET) abilities. From time-of-flight measurements, values of electron mobilities for NPB and 2TNATA are (6–9)×10−4 and (1–3)×10−4cm2∕Vs, respectively, under an applied electric field range of 0.04–0.8MV∕cm at 290K. An organic light-emitting diode that employed NPB as the ET material was demonstrated. The electron conducting mechanism of NPB and 2TNATA in relation to the Marcus theory [Rev. Mod. Phys. 65, 599 (1993)] from quantum chemistry will be discussed.