Bulk and interface properties of molybdenum trioxide-doped hole transporting layer in organic light-emitting diodes

✍ Scribed by Won-Ju Shin; Je-Yun Lee; Jae Chang Kim; Tae-Hoon Yoon; Tae-Shick Kim; Ok-Keun Song

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 542 KB
• Volume: 9
• Category: Article
• ISSN: 1566-1199
• DOI: 10.1016/j.orgel.2007.12.001

✦ Synopsis

Effects of doping molybdenum trioxide (MoO 3 ) in N,N 0 -diphenyl-N,N 0 -bis(1,1 0 -biphenyl)-4,4 0 -diamine (NPB) are studied at various thicknesses of doped layer (25-500 A ˚) by measuring the current-voltage characteristics, the capacitance-voltage characteristics and the operating lifetime. We formed charge transfer complex of NPB and MoO 3 by co-evaporation of both materials to achieve higher charge density, lower operating voltage, and better reliability of devices. These improved performances may be attributed to both bulk and interface properties of the doped layer. The authors demonstrated that the interface effects play more important role in lowering the operating voltage and increasing the lifetime.