Mwt architecture for thin si solar cells

Abstract

Methods of fabricating metal wrap through solar cells and modules for thin silicon solar cells, including epitaxial silicon solar cells, are described. These metal wrap through solar cells have a planar back contact geometry for the base and emitter contacts. Fabrication of a metal wrap through solar cell may comprise: providing a photovoltaic device attached at the emitter side of the device to a solar glass by an encapsulant, the device including busbars on the device emitter; forming vias through the device base and emitter, the vias terminating in the busbars; depositing a conformal dielectric film over the surface of the vias and the back surface of the base; removing portions of the conformal dielectric film from the ends of the vias for exposing the busbars and from field areas of the base; and forming separate electrical contacts to the busbars and the field areas on the back surface of the solar cell. The solar cells may comprise epitaxially deposited silicon and may include an epitaxially deposited back surface field.