Photovoltaic behavior of the merocyanine dye family with a rhodanine ring has been systematically studied by employing eight different derivatives in the diode structure Al/evaporated dye/Ag. Each dye film behaves like a p-type semiconductor with a rectifying barrier at Al interface and an Ohmic contact at Ag electrode. The open circuit photovoltage as high as Voc≃1.5 V was observed for one of the derivatives, while the fill factor remained f.f.≃0.25 in all cases. The chemical stability of the dye molecules during and after evaporation is also discussed on the basis of the results obtained by the thin-layer chromatography.