Reduction of degradation losses in Cz-Si solar cells

The reduction of the lifetime degradation losses in Cz-Si solar cells offers a potential for a significant increase of cell efficiency. The major components of the metastable defect underlying the lifetime degradation can be concluded from a couple of recent experimental results: boron and interstitial oxygen. Consequently, one strategy in order to reduce the degradation extent is obvious: the reduction or avoidance of either boron or interstitial oxygen in the starting material. If this is not possible the process should be optimized in order to reduce the defect concentration. Both possibilities have been successfully investigated resulting in excellent efficiencies up to 22.5 %.