Since it is a high quality crystal?
With solar cells' product process I mean the standard procedure of solar cell for Czochralski silicon solar cell.
We have fabricated back junction solar cells on n-type FZ-Si which feature an Al-alloyed pn junction. The junction is formed by firing an aluminium paste. Such back junction devices need very high diffusion lengths (higher than the one of standard front junction cells). Since we have achieved very nice conversion efficiencies around 20%, this shows that the electrical properties of FZ-silicon can be very good after an Al friring step.
See
https://www.researchgate.net/publication/259638580_TOWARDS_20__EFFICIENT_N-TYPE_SILICON_SOLAR_CELLS_WITH_SCREEN-PRINTED_ALUMINIUM-ALLOYED_REAR_EMITTER?ev=srch_pub
or
https://www.researchgate.net/publication/259638594_STATUS_AND_PERSPECTIVES_OF_N-TYPE_SILICON_SOLAR_CELLS_WITH_ALUMINIUM-ALLOYED_REAR_EMITTER?ev=srch_pub
Conference Paper Toward 20% efficient n-type silicon solar cells with screen-...
Conference Paper Status and Perspectives of n-Type Silicon Solar Cells with A...
Maybe the tolerence of impurities in n-type silicon is better than that in p-type silicon, at least for iron?
Yes, you are right.
See: D. Macdonald and L. J. Geerligs, Recombination activity of interstitial iron and other transition metal point defects in p- and n-type crystalline silicon, Applied Physics Letters 85, pp. 4061-4063 (2004).
However, it is also possible to maintain a high lifetime level using p-type FZ-Si. Unfortunately, the cell results for p-type cells with full Al-BSF are often limited by the surface recombination velocity at the rear side and thus the potential advantage of FZ-Si is not visible anymore.
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