SBIR Phase II: Dye Co-Sensitizer Combinations for Increasing the Efficiency of Dye-Sensitized Titania Nanoparticles in Solar Cells

This Small Business Innovation Research(SBIR) Phase II project aims to commercialize lightweight, flexible, affordable solar cells and modules that efficiently generate electricity from sunlight or indoor room light. These cells are based on dye-sensitized titania which is coated on a flexible substrate at high speed in a continuous coating, laminating process. The overall objective of Phase II is to raise the cell efficiency from its current 7% to 10% or higher, thereby raising the module efficiency from 5% to over 8%. To accomplish this, the ability of the sensitizing dyes to harvest a much larger number of available photons and convert them into electrons must be increased. In Phase I of this program, a new class of sensitizing dyes that cover a larger portion of the solar spectrum, have larger absorptivity than the currently used ruthenium-based dyes was discovered. In addition, materials that have similar molecular structures to those of the new sensitizing dyes, and act as co-sensitizers by boosting electron injection from the dye to the titania, are co-adsorbed with the dyes on the surface of the titania. It is anticipated that the combination of these materials will bring the cell and modules performance to the desired level. Commercially, the project will result in an inexpensive, efficient, flexible photovoltaic (PV) technology that can be integrated into consumer products. Therefore a renewable source of energy could be used to power products, minimizing the battery capacity and disposal requirements, and ultimately delivering power to building structures, avoiding emissions associated with fossil fuels. Security is a broad benefit on two levels. First, grid instability demonstrated by widespread blackouts in 2003 emphasizes the need for distributed power in our national grid. Secondly, growing homeland security concerns underscore the importance of wireless networks of sensors, cameras, and other monitoring systems for building and border security. Photovoltaics are uniquely suited to serve these distributed applications.