Abstract: A method of supporting a plurality of planar substrates in a tube shaped furnace for conducting a thermal treatment process is disclosed. The method uses a boat fixture having a base frame including two length portions and a first width portion, a second width portion, and one or more middle members connected between the two length portions. Additionally, the method includes mounting a removable first grooved rod respectively on the first width portion, the second width portion, and each of the one or more middle members, each first grooved rod having a first plurality of grooves characterized by a first spatial configuration. The method further includes inserting one or two substrates of a plurality of planar substrates into each groove in the boat fixture separated by a distance.

Abstract: A method of processing a thin-film absorber material with enhanced photovoltaic efficiency. The method includes providing a soda-lime glass substrate having a surface region and forming a barrier material overlying the surface region, followed by formation of a stack structure including a first thickness of a first precursor, a second thickness of a second precursor, and a third thickness of a third precursor. The first thickness of the first precursor is sputtered with a first target device including a first mixture of copper, gallium, and a first sodium species. The method further includes subjecting the soda-lime glass substrate having the stack structure in a thermal treatment process with at least H2Se gas species at a temperature above 400° C. to cause formation of an absorber material. Moreover, the method includes transferring a second sodium species from a portion of the soda-lime glass substrate via gas-phase diffusion during the thermal treatment process.