Thin film silicon solar cells on upgraded metallurgical silicon substrates prepared by liquid phase epitaxy

Thin layers of about 30 μm thickness were grown on upgraded metallurgical (UMG) silicon substrates by liquid phase epitaxy (LPE) from an indium solvent. Instead of adding electronic grade silicon to the solution, a melt back step was carried out before each growth process to supply silicon to the melt from the UMG-Si wafers. We present an LPE technology which is capable to be directly scaled up to a few hundred layers per run. Solar cells have been fabricated based on phosphorous paste diffusion with efficiencies up to η=10.0%.