The spotlight, page-8

Warren - The cesium perovskite solar photovoltaics technology is still in R&D and I guess the first prototype devices will begin to appear over the next few years when they get the stability and production issues sorted out. A recent review: https://www.ncbi.nlm.nih.gov/pubmed/29770979
But this will only happen if cesium is readily available - and that is where PIO come in. What we don't want to happen is a replay of the situation in 1993 when I started getting orders for cesium  formate brine from Shell and found that there wasn't sufficient cesium available commercially to even conduct a pilot/field trial. Cabot fixed that problem back then, albeit five years late. Hopefully PIO and SinoMine will come to the rescue of the photovoltaics industry in 2020 and beyond.  Or not, if they don't find any more pollucite in the Dome.