Yes, high-efficiency cells have been around for a long time for cost-no-object applications, mainly space.
What's changing is commercialization. Two or three of the big Chinese manufacturers have pilot projects going for two-layer cells. Of the order of 10 MWe, that sort of size. (I can't remember which companies, sorry; it was a few weeks ago I read about this. Probably at least one of Jinko, JA Solar, or LONGi is in there, as well as one or two of the second tier.) Also in the West there are a few startups working on two-layer cells, either perovskite on silicon or perovskite on perovskite.
(Perovskites are more easily "tunable" in terms of which frequencies of light they absorb, apparently--that's one of their attractions.)
What's changing is commercialization. Two or three of the big Chinese manufacturers have pilot projects going for two-layer cells. Of the order of 10 MWe, that sort of size. (I can't remember which companies, sorry; it was a few weeks ago I read about this. Probably at least one of Jinko, JA Solar, or LONGi is in there, as well as one or two of the second tier.) Also in the West there are a few startups working on two-layer cells, either perovskite on silicon or perovskite on perovskite.
(Perovskites are more easily "tunable" in terms of which frequencies of light they absorb, apparently--that's one of their attractions.)