Nanotube Transparent Electrodes for Nanomaterial Photovoltaics

Eikos Inc. and the National Renewable Energy Laboratory propose to develop nanomaterial 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). Branded as Invisicon®, our patented technology has already been successfully employed to improve solar cell performance. Eikos collaborates with the National Renewable Energy Lab and leading companies to fabricate organic, CIGS, and other solar cells incorporating Invisicon® for military and commercial applications. Having demonstrated our ability to integrate into a wide variety of solar technologies, we now propose to integrate Invisicon® 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, improving efficiency of future four junction solar cells. Invisicon® will ease manufacturing tolerances and lower PV production cost by improving the cell performance at minimal added cost, making multi-junction PVs more attractive for terrestrial concentrators. Nanotubes are exceptionally stable at high temperatures and under intense irradiation, making them ideal materials for space applications. 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.