Patent ID: 8178778

Claim:
A photovoltaic conversion element comprising: a semiconductor substrate of a first conductivity-type; a semiconductor layer of a second conductivity-type different than the first conductivity-type on the semiconductor substrate, thereby forming a pn junction between the semiconductor substrate and the semiconductor layer; an electrode on the semiconductor layer; and a depletion region extending in a direction from the pn junction into the semiconductor substrate and in a second direction from the pn junction into the semiconductor layer, wherein the depletion region comprises a first depletion region inside the semiconductor substrate and under the electrode, wherein the first depletion region has an oxygen concentration of 1E18 [atoms/cm 3 ] or less, wherein the semiconductor substrate has an oxygen concentration higher than 2E17 [atoms/cm 3 ] at a point of 10 μm in depth from the pn junction, and wherein an oxygen concentration profile in the semiconductor substrate decreases in the direction from the pn junction into the semiconductor substrate, reaches a minimum value and then increases to form a convex shape and an inflection point.