SOLAR CELL

A solar cell is discussed. The solar cell includes a substrate, a first electrode on the substrate, a second electrode, and at least one photoelectric transformation unit positioned between the first electrode and the second electrode. The at least one photoelectric transformation unit includes a p-type semiconductor layer, an intrinsic (i-type) semiconductor layer, an n-type semiconductor layer, and a buffer layer positioned between the p-type semiconductor layer and the i-type semi-conductor layer. A hydrogen content of the buffer layer is more than a hydrogen content of the i-type semiconductor layer.