The investigations on the optical and electrical characteristics of the OLEDs using an inorganic buffer material

Autor: Yung-Chen Chen, 陳永錚
Rok vydání: 2006
Druh dokumentu: 學位論文 ; thesis
Popis: 94
Metal oxide films play the role of the buffer-layer and hole-injection layer, and improve the interface roughness problem between organic materials and ITO electrode. They also increase the hole-injection efficiency for more hole-electron to recombine and emit photon in the organic emission layer, and achieve the goals for making OLEDs devices with low driving voltage and high power efficiency. In this study, we try to deposit ZnO:Li、Mg films by thermal evaporation method as the inorganic buffer layer in OLEDs devices, and also investigate the mechanism how the Li、Mg doped ZnO buffer layers can be used for improving the device efficiency. In the first phase of this research, we deposited Li、Mg doped ZnO films with different concentration and thickness as the buffer layer to investigate the characteristics of the OLEDs. We also studied the mechanism for those devices and measured the structures and the optical-electrical characteristics of those metal oxide films. In this study, we found that doping Li metal in the ZnO powder can increase the work function of ZnO films. As we chose the materials that their work functions closed to the HOMO of NPB, they could be used for improving the hole-injection efficiency and lowering the driving voltage.
Databáze: Networked Digital Library of Theses & Dissertations