Enhanced electroluminescence and reduced efficiency roll-off in electrophosphorescent devices using a very high electron mobility material as emitter host and electron transporterLi, T L; Li, W L; Chu, B; Su, Z S; Chen, Y R; Han, L L; Zhang, D Y; Li, X; Zang, F X; Sum, T C; Huan, A C H · Journal of Physics D: Applied Physics · 2009