Electron transport in naphthylamine-based organic compounds

Two naphthylamine-based hole transporters, namely, $N,N^{\prime }$ -diphenyl-$N,N^{\prime }$ -bis(1-naphthyl)($1,1^{\prime }$ -biphenyl)-$4,4^{\prime }\text{diamine}$ (NPB) and $4,4^{\prime },4^{″}$ -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 $(6–9)\times {10}^{-4}$ and $(1–3)\times {10}^{-4}{\mathrm{cm}}^2∕\mathrm{V}\mathrm{s}$ , respectively, under an applied electric field range of $0.04–0.8\mathrm{MV}∕\mathrm{cm}$ at $290\mathrm{K}$ . 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.