Advanced Space Power Technologies

Eikos Inc. proposes to develop composite carbon nanotube-metal oxide transparent electrodes to enhance the efficiency of three junction solar cells. Eikos leads the world in developing transparent conductive electodes based on carbon nanotubes (CNTs). Eikos also has demonstrated that the performance of nanotube electrodes can be tuned by using apprpriate binders to stabilize the nanotube network. Branded as Invisicon®, our patented technology has already been successfully employed to improve solar cell performance. Eikos has fabricated organic, CIGS, CdTe, and other solar cells incorporating Invisicon®. We now propose to integrate Invisicon® with space stable metal oxide and organic binders into three junction very high efficiency solar cells as a transparent electrode. Carbon nanotube electrodes will reduce shadowing from the metal grid and will allow the AlInP layer to be thinned, while improving carrier transport and acting as an anti-reflective coating. CNT coatings are exceptionally transparent through the visible and into the infrared. Nanotubes are exceptionally stable at high temperatures and under intense irradiation, making them ideal materials for space applications. The addition of appropriate space-stable binders will further enhance the stability of nanotube electro-optical properties. High performance solar cells with Invisicon® will have improved theoretical efficiencies at reduced cost, which will make them the new standard for space applications and open emerging markets for terrestrial applications.