In a method of manufacturing a solar cell, a first dopant layer is formed on a lower surface of a substrate and a diffusion-preventing layer is formed on an upper surface of the substrate. Then, the first dopant layer is patterned to expose portions of the lower surface of the substrate, and a second dopant layer is formed on the exposed portion of the lower surface of the substrate. A third dopant layer is formed on the diffusion-preventing layer, and the substrate is heated to diffuse dopants from the first, second, and third dopant layers into the substrate, thereby forming semiconductor areas in the substrate.