Skip to main content
SHARE
News

Imaging – Ionic moves

The ORNL team used atomic force microscopy to characterize ionic movement at a solar material’s surface. Using other microscopy techniques, spectroscopy and simulations, they analyzed ionic movement deeper down, revealing ionic movement across grain boundaries where iodine and chlorine compete to bond with a methyl ammonium functional group. Because iodine coordinates with methyl ammonium better than chlorine, the chlorine is more likely to migrate when an electric field is applied. Credit: Stephen Jesse/Oak Ridge National Laboratory, U.S. Dept. of Energy

September 5, 2017 – An Oak Ridge National Laboratory team discovered that adding chloride to promising photovoltaic materials enhances their ionic conduction, signaling a step toward developing electrically and optically tunable technologies. “We combine advanced synthesis methods to create materials with improved properties and advanced imaging techniques to see how material behavior has been enhanced,” said ORNL’s Olga Ovchinnikova. At the Center for Nanophase Materials Sciences, the researchers synthesized organo-metallic trihalide perovskites and imaged their electrochemistry with sophisticated techniques. “Through this powerful combination, we build a deeper understanding of mechanisms and phenomena at play at the nanoscale and learn how to tailor the synthesis and processing of materials to tune their functionality for various optoelectronic devices,” Ovchinnikova said. Their finding could benefit development of memristors that employ ions in memory storage and synaptic devices that use chemistry to drive information through logic gates.