If you are talking about the common flat-plate PV collectors, then most of them have a bulk of P-type substrate (grounded when installed), with a thin N-type on top surface.
Sanjoy is okay. The p-substrate is still dominating the production because of the maturity of the production processes. While the n-type substrate can outperform the p-type substrate because its higher lifetime of minority carrier and hence the higher achievable conversion efficiency.Also, there is no degradation with time as in p-type because no formation of boron-oxygen defects.
I asked a similar question on the research gate and got very valuable answers, so i would like to add here the link of the question:https://www.researchgate.net/post/Why_are_the_commercial_single_crystalline_silicon_solar_cells_normally_made_of_p-type_substrates