Grain Boundary Passivation in Multicrystalline Silicon Using Hydrogen Sulfide

A new grain boundary passivation method for multicrystalline silicon using hydrogen sulfide has been developed in this work. It has the added benefit of both hydrogen and sulfur for grain boundary passivation. Minority carrier lifetime of the samples is measured to monitor the effect of passivation. It is found that sulfur passivation takes place at higher temperatures, similar to 100 degrees C higher, than hydrogen passivation, and sulfur passivation results in much higher lifetime gains than hydrogen passivation. Post-annealing in ambient further improves the lifetime of the samples, which is attributed to improved surface passivation on the p-type silicon samples by aluminum oxide. The highest lifetime gain achieved after post-annealing is 6750% over the control sample for hydrogen sulfide annealed samples vs. similar to 2400% for forming gas annealed samples. Post-annealing also improves the stability of the passivation. (C) The Author(s) 2015. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives 4.0 License (CC BY-NC-ND, http://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial reuse, distribution, and reproduction in any medium, provided the original work is not changed in any way and is properly cited. For permission for commercial reuse, please email: oa@electrochem.org. All rights reserved.