Disclosed is a solar cell including a semiconductor substrate, and a dopant layer disposed over one surface of the semiconductor substrate and having a crystalline structure different from that of the semiconductor substrate, the dopant layer including a dopant. The dopant layer includes a plurality of semiconductor layers stacked one above another in a thickness direction thereof, and an interface layer interposed therebetween. The interface layer is an oxide layer having a higher concentration of oxygen than that in each of the plurality of semiconductor layers.