Improved fracture strength of multicrystalline silicon by germanium doping

The impact of germanium doping on the fracture strength of multicrystalline silicon (mc-Si) has been investigated by three-point bending testing. It is found that after the damaged layer removal by chemical etching, germanium doped multicrystalline silicon (Gmc-Si) wafers show significantly improved fracture strength compared to conventional mc-Si ones. Moreover, the improvement of the percentage of the fracture strength increases with decrease in thickness of the etched wafers. This suggests that the fracture toughness of mc-Si wafers is enhanced by germanium doping. The results are of interest for solar cells production yields improvement in the photovoltaic industry.