US Patent 7259324 Photovoltaic solar cell

A photovoltaic cell comprising, a cathode layer, an electron donating layer, and an electron accepting anode structure comprising a collection region including one or a plurality of secondary collection regions attached to the collection region. The secondary collection regions of the anode preferably are in the shape of dispersed rod shaped branches extending within a continuous phase of the electron donating layer. The collection region is preferably located at a central point with respect to the secondary collection regions, to thereby provide a photovoltaic cell structure with improved charge collection and efficiency of operation.