Growth of low defect density mc-Si ingots and wafers for PV application

An optimized seeded growth of multicrystalline silicon (mc-Si) ingot with modified hot zone and recipe of directional solidification is reported. Low defect density, as well as a higher and more uniform minority carrier lifetime, in the mc-Si ingot were observed with the optimized hot zone and recipe compared to the baseline growth conditions. A comparative study with two groups of solar cells made with the same fabrication process demonstrated an increase in average solar cell conversion efficiency by about 0.3% and in open circuit voltage by about 4 mV in absolute value.