Work function tunable metal-mesh based transparent electrodes for fabricating indium-free organic light-emitting diodes

Abstract

In order to realize low-cost and efficient organic light-emitting diodes (OLEDs), the transparent anode should have excellent optical and electrical properties, among other factors. Typically, transparent conductive oxides have been widely used for transparent top electrodes, but they suffer from several drawbacks. We herein report the fabrication of efficient indium-free transparent OLEDs using metal-mesh based top electrodes, made of any metal of choice, Au, Ag or Cu. The fabricated devices on inch square substrates exhibited superior emission characteristics without any color shift. In terms of workfunction matching, Cu did the best. With a Cu-TCE of low sheet resistance (∼7 Ω sq-1), uniform emission characteristics were achieved with relatively high current efficiency and luminance, comparable to those from the ITO based devices.