Optically thin silver and copper films are attracting growing attention for a variety of emerging applications, particularly for flexible optoelectronics. For large area, cost sensitive applications such as photovoltaics, copper is an attractive alternative to silver because it offers comparable electrical conductivity at much lower cost. The drawback of copper is its higher susceptibility to oxidation in air and its higher absorption of blue light, and so its potential for applications has been sparsely investigated. This talk will describe a new, scalable approach to improving the transparency of optically thin copper films by patterning with an array of ~ 100 million apertures cm-2, based on polymer blend lithography. Additionally a new way to dramatically retard oxidation of optically thin copper films without electrically isolating the metal or degrading its optical properties will be described based on an ultra-thin hybrid organic-inorganic adhesion layer. The potential utility of these nanostructured electrodes as window electrodes in high performance inverted organic photovoltaic devices will also be presented. Taken together it is anticipated these developments will stimulate interest in the utility of copper window electrodes for a variety of emerging applications.