Advantage in solar cell efficiency of high-quality seed cast mono Si ingot.

We have grown 50 cm² mono Si ingots by the seed cast technique. The carbon and oxygen concentrations of the ingots have been significantly reduced by improving the gas flow condition and coating. The dislocation density was also reduced by eliminating the extra dislocation generation sources. Owing to these developments, the lifetime of wafers has reached 465 µs. Finally, the efficiency of 18.7% has been achieved, which is comparable to 18.9% of the reference Czochralski (CZ) Si wafer. [ABSTRACT FROM AUTHOR]