[tofof]

(A sibling comment is wildly off the mark, and rather than reply and have my information buried far down the page, I'd rather it stay visible:)

The lead/caesium iodides are from the perovskite photovaic material (eg CsPbI₃, FA₀.₅MA₀.₅PbI₃, CH₃NH₃PbX₃ etc) that's being recycled* in the first place, and is the desired output - new photovaic material. That's the entire point, in fact - that at end of life, perovskite-based PV panels are otherwise toxic waste. This process recovers nearly 100% of these materials and allows their reuse in a new PV panel. If you're talking about perovskite PV, you almost always implicitly mean lead perovskites, and the highest efficiency we've found so far are inorganic perovskites like CsPbI₃.

In particular, perovskite PV are far FAR easier to manufacture - traditional silicon panels involve cleanrooms, high vacuum, and 1000+ C steps, while perovskite panels are very tolerant of defects and quite simple to manufacture - they can even be printed with inkjet or even screen printing technology.

This process is effecient enough that even on the 5th round of recycling (100 years of reuse, assuming a 20 year panel lifespan) they're something like 88% as efficient as a new panel, and the perovskite crystals are still at 99.998644% purity.

The solvent is indeed green - just water, sodium acetate, sodium iodide, and hypophosphorous acid.

The abstract is also clear that this is total panel recycling: "We further extend the scope of recycling to charge-transport layers, substrates, cover glasses and metal electrodes." Later in the paper they elaborate that after a brief low heat (150 C for 3 minutes) treatment to delaminate the EVA encapsulation, the panels are "then layer-by-layer recycled to reclaim cover glass, spiro-OMeTAD, perovskite crystal powders and SnO2-coated ITO substrates."

* As a control, they created fresh perovskite from the same technique as the recycling but from pure, purchased reagents, to assess the efficiency difference between them. That's the only place that fresh PbI and CsI appear.

[mapt]

I appreciate the comment. What obstacles remain in the way of taking over the commercial market?

[metalman]

pervoskite, is a fancy way of not saying lead, and lead will oxidise, into crusty stuff, that is not nice for most life forms. So the challeng is to encapsulate the lead based photo voltaic material for 20 + years. It has to be perfect, which is very very difficult to do, and as far as I know, has never been achived in the format that will be needed for large scale deployment. I personaly live off grid (15+ years) and would welcome an even better type of pannel, but getting these perovskite pannels past the remaining hurdles......in a truely price competitive format...is not a solved problem the test will be, a new sealing method that is so good, and so cheap, that it takes over all similar sealing dutys, like windows, world wide.