There's a vast number of esoteric PV cell types you can't actually buy at any reasonable price, or buy at all at any price, unless you're in an extremely specia

There's a vast number of esoteric PV cell types you can't actually buy at any reasonable price, or buy at all at any price, unless you're in an extremely specialized market niche. Note the PDF link above to best research cell efficiencies, which means somebody made a very small number of PV cells in a lab environment. Not something that's produced for sale to end-users in any real quantity.