Defect passivation on cast-mono crystalline screen-printed cells
- 131 Downloads
Cast-mono crystalline silicon wafers contain crystallographic defects, which can severely impact the electrical performance of solar cells. This paper demonstrates that applying hydrogenation processes at moderate temperatures to finished screen print cells can passivate dislocation clusters within the cast-mono crystalline silicon wafers far better than the hydrogenation received during standard commercial firing conditions. Efficiency enhancements of up to 2% absolute are demonstrated on wafers with high dislocation densities. The impact of illumination to manipulate the charge state of hydrogen during annealing is investigated and found to not be significant on the wafers used in this study. This finding is contrary to a previous study on similar wafers that concluded increased H– or H0 from laser illumination was responsible for the further passivation of positively charged dangling bonds within the dislocation clusters.
Keywordssilicon solar cell dislocation cast-mono laser hydrogen passivation
Unable to display preview. Download preview PDF.
- 9.Sopori B L, Deng X, Benner J P, Rohatgi A, Sana P, Estreicher S K, Park Y K, Robertson M A. Hydrogen in silicon: a discussion of diffusion and passivation mechanisms. In: IEEE 1st World Conference on Photovoltaic Energy, 1994, 2(95): 159–169Google Scholar
- 14.Hallam B, Sugianto A, Mai L, Xu G Q, Chan C, Abbott M, Wenham S, Uruena A, Aleman M, Poortmans J. Hydrogen passivation of laser-induced defects for silicon solar cells. In: Proceedings of IEEE 40th Photovoltaic Specialist Conference, 2014Google Scholar
- 15.Abbott M, Cousins P, Chen F, Cotter J. Laser-induced defects in crystalline silicon solar cells. In: Proceedings of IEEE Photovoltaic Specialist Conference, 2005Google Scholar
- 19.Song L, Wenham A, Wang S, Hamer P, Ahmmed M S, Hallam B, Mai L, Abbott M, Hawkes E R, Chong A M, Wenham S R. Laser enhanced hydrogen passivation of silicon wafers. International Journal of Photoenergy, 2015, 193892Google Scholar
- 35.Wenham A, Hallam B, Song L, Wang S, Abbott M, Chan C, Hamer P, Azmi A, Barnett A, Wenham S R. Efficiency enhancement for screen printed solar cells on Quasi-Mono wafers through advanced hydrogenation. In: Proceedings of the European PV SEC, 2015Google Scholar