Methods and devices are provided for high-efficiency solar cells. In one embodiment, an assembly is provided comprising of a plurality of solar cells each having at least one transparent conductor, a photovoltaic layer, at least one bottom electrode, a plurality of emitter wrap through (EWT) vias containing a conductive material, and a plurality of series interconnect vias containing a conductive material. The assembly may also include a backside support coupled to the solar cells, wherein the backside support is patterned to have electrically conductive areas and electrically nonconductive areas that create a series interconnect between solar cells electrically coupled by the support and prevents parallel connections between the solar cells. The cells may have a via insulating layer in each via separating the conductive material in each via from any side walls of the bottom electrode.