Advances in surface passivation of c-Si solar cells

In order to avoid an unacceptably large efficiency loss when moving towards thinner silicon materials, the near-term challenge in the c-Si PV industry is to implement an effective passivation method for both cell surfaces. This paper discussed several suitable passivation schemes available. While the efficiency potential of industrially produced thin film poly-Si cells on foreign substrates cannot yet reliably be predicted, it is clear that wafer-based c-Si solar cells will allow to maintain (or even improve) today’s efficiency levels while at the same time reducing the consumption of (expensive) crystalline silicon by up to 50 %. Given the trend towards these Si materials, the most promising surface passivation methods are identified to date. The key issues to be considered are cost-effectiveness, added complexity, additional benefits, reliability, and efficiency potential. The efficiency increase for best cells is around 0.5–0.6 %abs and the current efficiency potential already demonstrated for all technologies is around 19.0 %. Average efficiencies in industrial mass production for selected technologies are 18.5–18.6 % for Cz and 17.1 % for mc-Si.