Impact of Controlled Ni Contamination on Silicon Solar Wafer Material

Abstract

Trace metal impurities are known to severely degrade the performance of silicon solar cells. The effect of Nickel dissolved in dilute cleaning solutions was studied in detail. Clean wafers were exposed to these mixtures.The resulting surface concentration and the effect on carrier lifetime upon thermal oxidation, were found to correlate with a first order relation to the concentration of Ni in the solution.The removal of Nickel from the surface by different cleaning recipes was evaluated and compared using thermal oxidation followed by carrier lifetime measurements.The resulting surface concentration and the effect on carrier lifetime upon thermal oxidation, were found to correlate with a first order relation to the concentration of Nickel in the solution.