A solar cell is provided comprising a substrate, a first insulating layer on a first surface of the substrate, the first insulating layer having a plurality of first openings that expose portions of the substrate, and a plurality of first electrodes electrically connected to the substrate through the first openings, wherein one or more of the first electrodes are configured so that a width of an upper portion located on the first insulating layer is wider than a width of a lower portion located in a corresponding first opening.