Surface plasmon-enhanced photocurrent in organic photoelectric cells

Enhanced photocurrent due to the excitation of surface plasmons (SPs) in organic photoelectric cells of MgF2/Al/copper phthalocyanine (CuPc)/Ag structure has been investigated. SPs were excited both at Ag/air and at Al/MgF2 interfaces, using the attenuated total reflection (ATR) method. The enhancement of the photocurrent due to SP excitation depended considerably upon the wavelengths of incident light. The origin of the enhancement is discussed, comparing the experimental results with the calculations of the light absorption in the cells. The results suggested that excitation of SPs induced an increase in the light absorption at the CuPc layer, which led to the enhanced photocurrent. It was found that the light absorption by SP excitation was substantially effected by the anomalous dispersion of the CuPc dye.