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

Konarka Technologies, Inc., Lowell MA

Investigators

Abstract

This Small Business Innovation Research (SBIR) Phase I project proposes to develop a critical understanding of the underlying mechanism affecting the efficiency of dye-sensitized titania solar cells (DSSC). This understanding is pivotal to the advancement of the technology and could help move the solar industry forward by overcoming cost and weight barriers. DSSC technology in general has experienced low efficiencies due in part to the back transfer of electrons from the titania to an oxidized dye species on the surface of the titania before the electron can reach the electrode, producing current. In this proposal a simple means of alleviating this energy wasting pathway by anchoring aromatic amines, known as co-sensitizers or donors, at low concentration along with the sensitizing dye to the surface of the titania nanoparticles will be investigated. A significant increase in the cell efficiency due to an increase in current when these species are present on the surface in combination with the dyes has been observed. Since these results contradict other work on aromatic amines used as either co-adsorbed species on titania, or as adducts to the sensitizing dye molecule itself, a study of the effects of structurally modified co-sensitizers on redox potential, photon to electron conversion efficiency, and kinetics of the electron transfer is needed to understand the photophysics of the mechanism. The commercial applications of this project will be in solar cells. DSSC technology holds the greatest potential for low cost photovoltaics due to the inexpensive materials used and the ability to manufacture in volume using roll-to-roll processes. The DSSC technology will be lightweight and flexible as well, two attributes that literally open up new applications including molded plastics that conform to the exterior of consumer electronic devices and flexible fibers that can be woven into fabrics.