A solar cell including a first conductive type semiconductor substrate; a first conductive type first semiconductor layer on a back surface of the semiconductor substrate; a second conductive type second semiconductor layer on the back surface of the semiconductor substrate at a height different from the first semiconductor layer, the second semiconductor layer being separated from the first semiconductor layer; and a passivation layer on the back surface of the semiconductor substrate. The passivation layer covers at least a portion of the first semiconductor layer and at least a portion of the second semiconductor layer. The passivation layer includes impurities.