Scientists Create Organic Photovoltaic Devices To Convert Light Into Electricity

The scientists are using the ionically self-assembled monolayers (ISAM) process to fabricate optoelectronic devices. The process allows molecule-thick layers of oppositely-charged materials to build up on a base structure.

In this case, one of the layers is made up of carbon molecules known as Fullerenes and another layer is a positively charged polymer. Fullerenes have high electron affinity, so they will accept electrons easily from photoexcited molecules of a conducting polymer, creating a polymer with a negative charge. The result is a material to be used in a solar cell, generating a current from a negatively charged Fullerene and a positively charged polymer.

Thus a photovoltaic device is created without the use of toxic solvents or expensive instruments and under ambient conditions.

The paper (PMSE 258), "Efficient charge generation in conjugate molecules," discusses the influences of the chemical composition, sequence, and distance of materials on the electronic properties, particularly efficient charge generation, in the process of creating organic photovoltaic devices. Authors are Thomas Piok, Charles Brands, Patrick J. Neyman, Artur Erlacher, Charuta Soman, Mary A. Murray, and Raoul Schroeder, all Virginia Tech physics students;.James R. Heflin and Willi Graupner, physics professors; Daniela Marciu, Adam Drake, and M.B. Miller, all of Luna Innovations, Inc. of Blacksburg, Va.; Hong Wang, Virginia Tech chemistry postdoctoral fellow; Harry W. Gibson, and Harry C. Dorn, Virginia Tech chemistry professors; Guenter Leising of the Institut fuer Festkorperphysik, Technische Universitat Graz; Mathew T. Guzy, Virginia Tech chemical engineering student; and Richie M. Davis, Virginia Tech chemical engineering professor.

The paper will be presented by Graupner on Wednesday, Aug. 23, at 9 a.m. in the JW Marriott Hotel Grand Ballroom, Salon III, as part of the Organic Thin Films for Photonic Applications symposium.