Researchers develop new light-sensitive crystalline material

Aug. 28 (UPI) -- Scientists have discovered a new family of perovskites capable of changing shape in reaction to light.

Most researchers have focused on the ability of perovskite crystals to harvest energy from sunlight. But as the latest research reveals, the crystalline material also exhibits a quality known as photostriction.

Photostriction describes an increase in internal strain triggered by exposure to light. The strain alters the material's internal structure and changes the material's shape.

Scientists studied the photostriction of a perovskite called MAPbBr3. Researchers used Raman spectroscopy to measure the material's internal molecular vibrations as it was exposed to light. Their analysis revealed an especially strong photostriction reaction.

"We demonstrated that in situ Raman spectroscopy with confocal microscopy is a powerful characterization tool for conveniently measuring intrinsic photoinduced lattice deformation," Tzu-Chiao Wei, a researcher at the King Abdullah University of Science and Technology, said in a news release. "The same approach could be applied to measure photostriction in other materials."

Researchers determined that the perovskite's photostriction reaction is partially triggered by its photovoltaic effect, the effect that makes it so valuable to solar panels. When exposed to light, the material's ions begin to move and the perovskite generates positive and negative charges.

Scientists described the new class of perovskites and its photostriction capabilities in a paper published this week in the journal Advanced Materials.

"We will use this material to fabricate next-generation optoelectronic devices, including wireless remote switchable devices and other light-controlled applications," Wei said.