Perovskite is a mineral, but it is also the name of a whole very large group of minerals, describing the crystalline structure their bonded atoms make, of which Perovskite proper, was the first discovered by a Russian by the same name.

Basically, there are Perovskite forms of many different minerals. My vague understanding is that they are usually multiple minerals merged, then crystallized into a new Perovskite version and that there are several that naturally form.

They've been refining use this stuff for similar purposes since at least the 1990's. They've gotten even higher efficiencies, but they were ridiculously too expensive. This new spin on the approach is important, because it gets most of the efficiency, but makes manufacturing it actually affordable....(if everything works out like it seems)