Indium-free, highly transparent, flexible Cu ₂O/Cu/Cu ₂O mesh electrodes for flexible touch screen panels

Abstract

We report on an indium-free and cost-effective Cu ₂O/Cu/Cu ₂O multilayer mesh electrode grown by room temperature roll-to-roll sputtering as a viable alternative to ITO electrodes for the cost-effective production of large-area flexible touch screen panels (TSPs). By using a low resistivity metallic Cu interlayer and a patterned mesh structure, we obtained Cu ₂O/Cu/Cu ₂O multilayer mesh electrodes with a low sheet resistance of 15.1 Ohm/square and high optical transmittance of 89% as well as good mechanical flexibility. Outer/inner bending test results showed that the Cu ₂O/Cu/Cu ₂O mesh electrode had a mechanical flexibility superior to that of conventional ITO films. Using the diamond-patterned Cu ₂O/Cu/Cu ₂O multilayer mesh electrodes, we successfully demonstrated TSPS of the flexible film-film type and rigid glass-film-film type TSPs. The TSPs with Cu ₂O/Cu/Cu ₂O mesh electrode were used to perform zoom in/out functions and multi-touch writing, indicating that these electrodes are promising cost-efficient transparent electrodes to substitute for conventional ITO electrodes in large-area flexible TSPs.