Organic light-emitting diode with indium-free metallic bilayer as transparent anode

Bilayer Cu-Ni transparent electrodes were room-temperature grown on glass by sputtering technique and used as anodes for polymer light-emitting diodes (PLEDs). The bilayer electrode structure allows combining the low sheet resistance and high transparency of Cu with the excellent stability and high work function of Ni. We demonstrate that Cu-Ni bilayer based PLED devices exhibit comparable efficiency and lifetime decay behavior to indium tin oxide (ITO) based device, with potentially significant advantages, such as easy processing, low cost and mechanical flexibility. In addition, the ductile nature of the metal electrode and its low thickness (< 10 nm) make the proposed structure particularly suitable for flexible organic electronic and optoelectronic devices. (C) 2011 Elsevier B.V. All rights reserved.