The focus is on how to prepare crystalline silicon films with grains in the 100 µm range on a glass substrate. To get large rather defect free grains melting and solidification of silicon is required. Due to the low soft point of glass this can not be done in a furnace. We use our LLC (layered laser crystallization) process relying on laser melting. An amorphous silicon layer on glass is scanned by a diode laser beam to melt the silicon for 1 ms. The melt then crystallizes to grains of about 100 µm. In this way a thin seed layer is prepared onto which the solar cell absorber is grown by depositing amorphous silicon by electron beam evaporation and repeated excimer laser irradiation. In this way an epitaxial layer up to several µm thick forms with the desired doping profile for a solar cell.

The group is also involved in laser processing of conventional silicon wafer cells.