Reduction of Light-induced Degradation of Boron-doped Solar-grade Czochralski Silicon by Corona Charging

This study aims at the reduction of light-induced degradation of boron-doped solar-grade Czochralski silicon wafers by corona charging. The method consists of deposition of negative charges on both surface sides of wafer and keeping the wafer in dark for 24 hours to allow the diffusion of positively-charged interstitial copper towards the surfaces. This method proves to be useful to reduce or eliminate light-induced degradation caused by copper. The degradation was significantly reduced in both intentionally (copper-contaminated) and “clean” samples. The amount of the negative charge was found to be proportional to the reduction strength