Interface and Electrode Engineering for Next-Generation Organic Photovoltaic Cells: Final Technical Report, March 2005 - August 2008

Abstract

The Northwestern University (NU) group combines expertise in first-principles electronic structure theory, exploratory synthesis, thin-film deposition, device fabrication, and characterization. Building on success at NU in developing improved organic light-emitting diodes, the program addressed two crucial aspects of organic photovoltaic (OPV) technology: 1) improved electrode-organic interfaces, and 2) improved transparent electrode materials. The NU group has extensive expertise in the area of unconventional transparent electrodes (or transparent conducting oxides, TCOs), including novel "nanostructured" TCO morphologies. The electronic properties of TCO surfaces (e.g., band offsets/work functions) are believed to play a crucial role in OPV performance. New TCOs were examined that better match (chemically and electronically) the organic components of OPV cells. The group also developed high-efficiency organic adhesion/current-collection layers for improved electrode-organic interfaces. The ultimate goal was to develop and test a high-efficiency prototype organic solar cell incorporating NU-developed interfacial and electrode materials.