Chemists from McGill University have found that the mineral perovskite is a new state of matter.
Perovskite is CaTiO3, the crystals of which have a pseudocubic (broken cubic) structure. It is mined for the rare earth minerals it contains.
It also showed high efficiency in both photovoltaic panels and LED light sources. It was previously unknown how this effect occurs.
There are defects in the crystal structure of perovskite, but it works better than a substance with an ideal crystal lattice.
Using pump-probe microscopy, one of the methods of nonlinear optical imaging for studying chemical reactions, scientists observed the dynamics of perovskite and found that deformation in the crystal lattice of a mineral does not lead to a decay of energy, but to its overall increase.
The authors explain this to those who are deformed perovskite crystal lattice following the movement of an electron and behaves like a liquid. In the process of electron movement through the mineral, two quasiparticles arise and combine – a polariton and an exciton. This is similar in results to the formation of a quantum dot in the material. More precisely, a quantum drop, if we talk about the properties of perovskite inherent in liquids.
Scientists have not previously observed such behavior in a substance. The authors of the new work argue that further study of perovskites will significantly improve their use in photoconverters.