Waves of light and sound interact to drive electronic and structural changes in a perovskite crystal. At the atomic scale, nothing is ever truly still. Materials that appear perfectly rigid and motionless to the naked eye are in fact swarms of vibrating atoms. This motion is generally random and uncoordinated, but with the right input, the atoms in certain materials will start to move together, vibrating in sync.
These collective vibrations are a form of sound called phonons, and when tuned just right, they can influence a material’s structure and behavior in dramatic and useful ways. Researchers are working to understand and control this effect to optimize material properties and even access hidden phases of matter.
Scientists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory are using light to drive phonon activity in a class of materials called metal halide perovskites, whose customizable structures and photosensitivity hold promise for use in next-generation solar cells, advanced sensors and quantum information technologies.








