Electrical conduction behavior of organic light-emitting diodes using fluorinated self-assembled monolayer with molybdenum oxide-doped hole transporting layer

The electrical conductivity behavior of a fluorinated self-assembled monolayer (FSAM) of a molybdenum oxide (MoOx)-doped -naphthyl diamine derivative (-NPD) in organic light-emitting diodes (OLEDs) was investigated. The current density of the MoOx-doped -NPD/FSAM device was proportional to its voltage owing to smooth carrier injection through the FSAM and the high carrier density of its bulk. The temperature-dependent characteristics of this device were investigated. The current density-voltage characteristics at different temperatures were almost the same owing to its very low activation energy. The activation energy of the device was estimated to be 1.056x10(-2) [eV] and was very low due to the inelastic electron tunneling of FSAM molecules. Copyright (c) 2014 John Wiley & Sons, Ltd.