Photoinduced alteration of the inner electric field in a Zn-phthalocyanine/C60 heterojunction solar cell

Electroabsorption (EA) and photocurrent measurements are carried out for a Au/Zn-phthalocyanine(ZnPc)/C60/In/Al heterojunction cell in order to elucidate the effect of photoexcitation of ZnPc or C60 on the inner electric field E0. By a pumping excitation of either the ZnPc or C60 layer, the E0 of the pumped layer is decreased and that of the other layer is increased. The photocurrent due to a probing-light illumination besides the pumping-light illumination has a good correlation with E0 under the pumping excitation of ZnPc but has no correlation under the pumping excitation of C60.