Electric field-induced hole injection-enhanced photoluminescence in a N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)-benzidine-based emitter

Abstract

Non-monotonic, asymmetrical electric field dependence of photoluminescence (PL) intensity is observed in a monolayer sample of tris-(8-hydroxyquinoline) aluminum (AlQ) doped N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)-benzidine (TPD). A possible model is proposed: the charge separation from the dissociated photoexcited excitons causes energy band bending in the organic films and improves the hole injection from the electrode, which brings about the extra fluorescence. This mechanism is further verified by a series of experiments using a series of samples, variously featuring symmetrical electrodes, block layers, and hosts with lower hole mobilities.

Effect of CuPc and Mo O 3 co-evaporated layer on the conductivity of organic light emitting diodes

“…Conductivity is an important factor that can greatly impact the performance of devices, such as organic photovoltaic (OPV), organic light emitting diodes (OLED). [1][2][3][4][5] However, the conductivity of organic small molecular materials is still poor compared with traditional inorganic materials because of their low charge mobility and low carrier density. [6,7] In 2001, Zhou et al found that the conductivity of TDATA can be greatly increased by F4-TCNQ doping.…”