I thought that might be the case. Unfortunate, I think it reads significantly better with deeper changes (updated my earlier post), but I'm familiar with the constraints you're under.

"thereby produce a *larger* fraction of high-value solar cells" is a minimal improvement, as would be substituting "increased value," "valuable," or "more valuable." I can see marketing folks being fairly set on high-value vs. alternatives, though.

Reading around, "high solar conversion efficiency" appears to be the standard phrasing. "High" should probably be retained there.