MULTI CRYSTALLINE SILICON THIN FILMS GROWN DIRECTLY ON LOW COST SODA-LIME GLASS SUBSTRATES

Liquid phase crystallization of silicon is a promising technology platform to grow multi crystalline silicon thin films on foreign substrates. For solar cell application it has already been demonstrated that open circuit voltages of up to 661 mV [1] and efficiencies of up to 15.9% [2] can be achieved on a silicon layer of a few microns only. However, while the quality of the material has been continuously improved, the cost factor of the utilized substrate has been given little attention. The present work focuses on the technology transfer from technical glass substrates to low cost soda-lime glass substrates to become more attractive for commercial applications. We demonstrate that despite a large difference in the expansion coefficient between soda lime glass and silicon absorber layer, adhesive silicon thin films can be produced under certain conditions. On these first layers, we were able to fabricate solar cells, which in their cell and material properties were only similar to 30% below the values of their technical glass counterparts.