The term “perovskites” is used in so many contexts these days that there seems to be a bit of misunderstanding with what these materials are all about. So, for those who are not familiar with what this class of solids represents, here is a quick word about perovskites.

Perovskites are distinguished as a separate class of materials not based on their strictly defined chemical makeup, or any physical characteristics, or specific applications. The term perovskite refers to the class of crystals which follow the crystal structure of a mineral calcium titanium oxide CaTiO₃ and known as a perovskite structure.

And this is basically it. Other than that, perovskites may show up in nature or be synthetized in the lab in the number of combinations in terms of chemical composition. What follows is a divers range of physical properties and resulting applications. For instance, on one hand perovskites are materials with a great potential in solar cells applications while on the other, with some compositional modifications, are the materials displaying dielectric and ferroic properties. 

Either way, in the case of perovskites crystallographic structure is a common denominator. This is in contrast to other classes of materials where chemical composition is a deciding factor, for instance III-V compounds.