NOVELTY - Fabricating a back contact single hetero-junction solar cell (400), comprises: providing a first semiconductor substrate; forming a third semiconductor layer (410) overlying the first semiconductor substrate topside (404); texturing a top surface of the third semiconductor layer; forming an emitter (414) in the substrate backside; forming a base (408) in the substrate backside; forming a first electrical contact (418) to the emitter; and forming a second electrical contact (420) to the base.    USE - The method is useful for fabricating a back contact single hetero-junction solar cell (claimed).    ADVANTAGE - The method produces solar cell with improved efficiency.    DETAILED DESCRIPTION - Fabricating a back contact single hetero-junction solar cell, comprises: providing a first semiconductor substrate lightly doped with a first dopant type, the substrate having a topside, a backside, and a first energy bandgap; forming a second semiconductor overlying a region of the substrate backside, the second semiconductor having a second energy bandgap, larger than the first energy bandgap; forming a third semiconductor layer overlying the first semiconductor substrate topside, moderately doped with the first dopant; texturing a top surface of the third semiconductor layer; forming an emitter in the substrate backside, heavily doped with a second dopant type, opposite of the first dopant type; forming a base in the substrate backside, heavily doped with the first dopant type; forming a first electrical contact to the emitter; forming a second electrical contact to the base; and where an electrode selected from the emitter and the base is formed in the second semiconductor. An INDEPENDENT CLAIM is a back contact single hetero-junction solar cell, the solar cell comprising: a first semiconductor substrate lightly doped with a first dopant type, the substrate having a topside, a backside, and a first energy bandgap; a second semiconductor film overlying a region of the substrate backside, the second semiconductor having a second energy bandgap, larger than the first energy bandgap; a third semiconductor layer with a textured top surface, overlying the first semiconductor substrate topside, moderately doped with the first dopant; an emitter in the substrate backside, heavily doped with a second dopant type, opposite of the first dopant type; a base in the substrate backside, heavily doped with the first dopant type; a first electrical contact to the emitter; a second electrical contact to the base; and where an electrode selected from the emitter and the base is formed in the second semiconductor film.    DESCRIPTION OF DRAWING(S) - The drawing shows a partial cross-sectional vie of a back contact single hetero-junction solar cell.    Solar cell (400)    Substrate (402)    Topside (404)    Backside (406)    Base (408, 416)    Third semiconductor layer (410)    Textured top surface (412)    Emitter (414)    First electrical contact (418)    Second electrical contact (420)    Heavily doped region (422)