A solar cell includes a substrate, a back electrode layer on the substrate, a light absorbing layer on the back electrode layer, a buffer layer on the light absorbing layer, and a front electrode layer on the buffer layer. The buffer layer includes at least one of zinc sulfide (ZnS), zinc oxide (ZnO) and zinc hydroxide (Zn(OH)2). A method of fabricating the solar cell includes forming a back electrode layer on a substrate, forming a light absorbing layer on the back electrode layer, forming a first buffer layer on the light absorbing layer, and forming a second buffer layer on the first buffer layer. The first buffer layer or the second buffer layer includes at least one of zinc sulfide (ZnS), zinc oxide (ZnO), and zinc hydroxide (Zn(OH)2).