Formation of a MgAu alloy Cathode by Photolithography and the Application for Organic Light-Emitting Diodes and Organic Field-effect Transistors

Abstract

To realize an efficient electron injection electrode into organic layers by photolithography, we form a MgAu alloy electrode which has capability of low work function and high durability for humidity and organic solvents during photolithography process. The MgAu alloy thin film shows a work function of 3.7eV which is comparable with that of a neat Mg layer and 0.8eV lower than that of a neat Au layer. The low work function of 3.7eV was maintained even after the photolithography process, suggesting excellent stability for the solvent treatments. We examine a MgAu alloy comb bottom electrode for organic field-effect transistor (OFET) and successfully obtain FET operation of n-type driving. We also demonstrate efficient electron injection characteristics of a MgAu alloy cathode in organic light-emitting diodes (OLEDs). The MgAu alloy cathode can inject electrons efficiently similar to the conventional MgAg cathode.