QUALITY INVESTIGATION OF B-DOPED MULTICRYSTALLINE SILICON INGOT GROWN USING FEEDSTOCK INTENTIONALLY CONTAMINATED WITH DIAMOND POWDER

摘要

In order to examine the influence of diamond powder impurity on the quality of multicrystallinesilicon ingot, 100 ppmw diamond powder was added as additional impurity during the B-doped ingot growthprocess. Carrier lifetimes around 10 μs were realized in most regions of the ingot after the ingot growth. Metalimpurities of the ingot were removed by phosphorus gettering and carrier lifetimes were improved to around 50 μsafter H-passivation at the center region of the ingot. The top of the ingot exhibited a p-type to n-type polaritychange. Solar cells were fabricated on wafers cut from the diamond powder contaminated B-doped silicon ingotand efficiencies up to14 % were confirmed similarly to a non-contaminated reference cell.