Abstract: A photoelectric conversion element having storage/discharge ability has a substrate layer that is formed of a conductive metal and is connected to a minus electrode of output electrodes, a collector electrode that is formed by being joined to one surface of the substrate layer, an n-type compound semiconductor layer that is formed of a dielectric composition containing a fullerene and is formed by being connected to the collector electrode, a p-type compound semiconductor layer that is formed in contact with the n-type compound semiconductor layer, and a pn-bulk layer that is formed between the n-type compound semiconductor layer and the p-type compound semiconductor layer and is intermittently in contact with the n-type compound semiconductor layer and the p-type compound semiconductor layer, and has a secondary battery arranged on the other surface of the substrate layer to provide a storage/discharge function. Also provided is the secondary battery preferably used herein.