Enhancement of Performance of Organic Light Emitting Diodes by Using Ti- and Mo-Oxide Nano Hybrid Layers
- 1 University of Engineering and Technology, Vietnam National University Hanoi, Hanoi, Vietnam
- 2 University of Engineering and Technology, Vietnam National University Hanoi, Hanoi, Vietnam
- 3 University of Engineering and Technology, Vietnam National University Hanoi, Hanoi, Vietnam
- 4 Water Resources University, Hanoi, Vietnam
- 5 Institute of Materials Science, Vietnamese Academy of Science and Technology, Hanoi, Vietnam
- 6 Department of Physics, Concordia University, Montreal, Canada
Abstract
Nanorod-like TiO 2 (nc-TiO 2 ) and MoO 3 (nc-MoO 3 ) films were thermally grown from Ti- and Mo-metallic wafers. Nanohybrid films of N,N’-diphenyl-N,N’-bis(1-naphthyl)(1,1’-biphenyl)-4,4’diamine (NPB )/TiO 2 and NPB/MoO 3 used as anode/hole transport layer (HTL) heterojunctions in blue organic light emission diodes (OLEDs) were prepared by coating NPB onto the nc-TiO 2 and nc-MoO 3 and TiO 2 . Characterization of the nanostructured hybrid layers showed that both the photoluminescent property and current-voltage (I-V) characteristics of the hybrid materials were significantly enhanced in comparison with the standard NPB polymer. The electroluminous efficiency of the hybrid devices was considerably enhanced in comparison with the standard device. This suggests a useful application for fabricating “re verse” OLEDs, where the emission light goes-out through the semitransparent cathode, instead of the indium tin oxide (ITO) anode. For this, the ohmic contacts of conducting wires to metallic electrodes can be made much better than to ITO anodes.
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