Low temperature liquid phase epitaxy with Sn-based solvent

Silicon thin film is an attractive option for solar cell applications because of their low cost potential. Liquid Phase Epitaxy (LPE) is an interesting technique because it allows growth of single crystal Si film even at low temperature (< 800 degrees C). Main difficulties are the low solubility of silicon in usual solvent and the presence of a native silicon oxide. In this study, we developed a technique using two successive different Sn-based melts, one to remove native oxide, second one to grow the active layer under argon or hydrogen flow. This technique leads to smooth and homogeneous Si layer presenting a p / p+ structure. Solar cells were fabricated using standard technology. The photo-generated current density is in the 16-19 mA/cm(2) range after of Si3N4 coating deposition. To improve active layer thickness and to enlarge the Si solubility, we proposed to use metallic alloys as Si-Sn-Cu-Al. (c) 2007 WILEY-VICH Verlag GmbH & Co. KGaA, Weinheim.