Description: The key to achieving high-power solar arrays for NASA applications is the development of high-efficiency, thin-film solar cells that can be fabricated directly on flexible, lightweight, polymer/plastic substrates. Current thin-film cell fabrication approaches are limited by either the ultimate efficiency that can be achieved with the device material and structure or the requirement for high-temperature deposition processes, especially of the transparent conducting electrode, which are incompatible with all presently known flexible polyimide or other polymer substrate materials. In this proposed R&D effort Materials Modification, Inc. will develop a novel, low-temperature and cost-effective technique for the preparation of nanostructured thin films of a transparent conducting oxide, for use as electrodes in Plastic solar cells.. In addition, a prototype plastic Heterojunction solar cell will be fabricated with this nanostructured material as an electrode instead of the conventional ITO, and the superiority of this system will be established