Light and elevated temperature induced degradation in p-type and n-type cast-grown multicrystalline and mono-like silicon

Abstract

We compare light induced degradation behaviours in lifetime samples and fully fabricated solar cells made from p-type boron-doped high performance multicrystalline silicon, p-type boron-doped mono-like silicon, n-type phosphorus-doped high performance multicrystalline silicon and p-type boron-doped Czochralski-grown silicon. Our results confirm that the degradation in multicrystalline silicon is triggered by the rapid cooling after the firing process. All cast-grown silicon samples subjected to fast cooling show lifetime reduction after light soaking. Interestingly, the degradation rate in n-type multicrystalline silicon is found to be orders of magnitude slower than in p-type multicrystalline silicon, suggesting that the defect formation mechanism could be affected by the positions of the quasi fermi levels.