I certainly hope these spray/use/coat-anywhere perovskites are lead-free, and there isn't much info on the other key issue with perovskites: they degrade quickly when exposed to oxygen/air/the atmosphere.
The article kind of sucks, like most gee-whiz solar reporting. Battery reporting IMO has gotten a bit better where they actually address cycles/density/materials.
Multijunction solar is still ridiculously undeveloped industrially, and perovskite or silicon+perovskite multijunction could lead to a lot of progress.
What's important about these articles is that solar, which is already exceptionally cheap in LCOE terms, still has runway to likely drop 50% in price in the next 10 years.
I continue to be frustrated with the cost of home/residential solar, which I think is a key part to avoiding excessive grid restruction, increasing resilience in disaster scenarios, double-utilizing already-industrialized/developed land/structures rather than using "pristine" land, and providing key competition to inherent-monopoly utilities.
So cheaper spray-on or coating-based solar might help close the residential vs grid solar gap.