R2R QD-solar produced in mass would be terrific, but speaking frankly; the "if and when" factor is key in this dialogue. Along with you & others, I've long been enthusiastic about the QD-solar concept becoming a commercial reality for obvious reasons, but to-date, no such commercial product exists...& from my limited perspective, I don't really see it anywhere on the near-term horizon. We've been waiting for this to take root since the hype way back in the KAUST/Saudi days, a seeming-eternity ago.
To my knowledge, the best 'benchtop' efficiencies achieved to-date worldwide are in the 8-9, possibly 10% range, which (unless I'm mis-informed) is still 5 or 6% below the minimum commercial acceptance threshold...& it took several years to even get to where it is now. At this rate, unless something really profound occurs, it looks like it will still be a long wait before any of this goes on-line, "if" at all. And with that said, I sincerely hope to be proven wrong