SOLAR CELL

摘要

A solar cell comprising a light-absorption layer of a compound semiconductor with a chalcopyrite crystal structure and having excellent characteristics such as the conversion efficient. The solar cell comprises a first electrode layer, a second electrode layer, a p-type semiconductor layer interposed between the first and second electrode layers, and an n-type semiconductor layer interposed between the p-type semiconductor layer and the second electrode layer. The p-type semiconductor layer comprises a semiconductor containing a group Ib element, a group IIIb element, and a group VI element and having a chalcopyrite structure. The bandgap of the p-type semiconductor layer increases from the n-type semiconductor layer side toward the first electrode layer side monotonously. The bandgap of the p-type semiconductor layer at the major surface on the n-type semiconductor layer side is above 1.08 eV, and that at the major surface on the first electrode layer side is above 1.17 eV. In the p-type semiconductor layer, the bandgap increase rate in the direction of the thickness of the p-type semiconductor layer in a first region on the n-type semiconductor layer side is different from that in a second region on the first element layer side.