Globally, it isn't used much, but about 20% of the US market is CdTe.

Ah, okay! It's quite possible that it's not widespread, I know because I had a course on renewable energies in my university studies (electrical engineering).

0xbitcoiner

I think he's just pointing out that you'd expect people to have heard of them if they're in fairly widespread use. I don't recall having heard of them before, but it seems like you already know the main points about them.