Abstract
Surface recombination velocities as low as 10
cm/s have been obtained by treated atomic layer deposition (ALD) of Al
2O
3 layers on p-type CZ silicon wafers. Low surface recombination is achieved by means of field induced surface passivation due to a high density of negative charges stored at the interface. In comparison to a diffused back surface field, an external field source allows for higher band bending, that is, a better performance. While this process yields state of the art results, it is not suited for large-scale production. Preliminary results on an industrially viable, alternative process based on a pseudo-binary system containing Al
2O
3 are presented, too. With this process, surface recombination velocities of 500–1000
cm/s have been attained on mc-Si wafers.