Photochemical approaches to conversion of light of electricity or fuel. Final report, April 1, 1991--April 30, 1995

Research supported by the Department of Energy focused on the development of molecular and semiconductor based approaches to the conversion of light to electricity or fuels. Studies of molecular systems included the preparation and characterization of new molecules which could serve as light absorbers and/or as elements that bring about charge separation following photoexcitation. Ring-opening metathesis polymerization, in particular, was demonstrated to be useful in preparing new functional polymers of importance in developing fundamental understanding of the excited state dynamics of multicomponent polymers for light absorption and charge separation. Charge separation and ultimate collection is essential to the development of efficient systems for the conversion of light to electricity or fuel. Molecular materials such as poly(p-phenylene-ethynylene)s represent possible semiconductor photovoltaic materials that can be both efficient and low cost. Study of the optical and electrical characteristics and excited state behavior of such new materials contributed to an understanding of the design parameters needed for efficient photovoltaic devices based on such materials. Approaches to functionalization of electrode, including photoelectrode, surfaces for the purpose of improving interface energetics and kinetics in photoelectrochemical devices show that a wide range of molecular chemistry can be applied to tailoring the properties of electrode/electrolyte interfaces