ENHANCEMENT OF PHOTOELECTRIC CONVERSION EFFICIENCY BY SURFACE-PLASMON EXCITATION - A TEST WITH AN ORGANIC SOLAR-CELL

An organic solar cell consisting of Al, copper phthalocyanine (CuPc) and Ag thin layers was prepared on a glass substrate and mounted on a glass prism to excite the surface plasmon polariton (SPP) in an attenuated total reflection geometry. The current-voltage characteristics of the cell were measured under illumination of the 5145 angstrom line of an Ar+-ion laser for the cases where the SPP is excited and not excited. It was found that the power conversion efficiency of the solar cell is enhanced by a factor of 7 under the SPP excitation. Calculations of electric field patterns and light absorption suggest that the observed enhancement is due to the increase in the photocarrier generation in the CuPc layer, which results from the enhanced light absorption under the SPP excitation.