A three-dimensional solar cell comprising a semiconductor substrate with an inverted pyramidal cavity, emitter metallization regions on ridges on the surface of the semiconductor substrate which define an opening of the inverted pyramidal cavity, and base metallization regions on a region which form the apex of the inverted pyramidal cavity. A method for fabricating a three-dimensional thin-film solar cell from an inverted pyramidal three-dimensional thin-film silicon substrate by doping ridges on the surface of the semiconductor substrate which define an opening of an inverted pyramidal cavity on the substrate to form an emitter region, and doping a region which forms the apex of the inverted pyramidal cavity to form a base region. Adding a surface passivation layer to the surface of the substrate. Selectively etching the passivation layer from the emitter region and base region. Then concurrently metallizing the emitter region and base region.