Strain engineering improves stability of perovskites

• A group of American scientists have succeeded in making a high-potential halide perovskite more stable under conditions of room temp. They have applied an epitaxial technology to keep the lattice of α-FAPbI3 from taking the shape of a hexagon.

A research team from US’s RPI has applied strain engineering to increase stability of halide perovskites. There is a considerable challenged related to α-FAPbI3. Under indoor temperature necessary for proper operation of a solar cell, originally cube-shaped lattice of the material tends to turn into a hexagon. Hexagonal lattice is unsuitable for responding to the majority of sunlight wavelengths. 

The scientific group has grown α-phase of formamidinium-based lead triiodide from the solution consisting of cubical atoms, shaping the growing lattice into pseudo-cubical crystals and keeping it from turning into hexagon. Room temperatures do not break stability of such pseudo-cubic crystals created by means of epitaxy during one year or even longer.

The scientists are not sure whether their findings will be used in production of perovskite solar devices right away. However, they claim that strain engineering can be equally useful for growing other types of halide perovskites with a similar structure but different electronic properties, which can be crucial for technological application.