Perovskite Crystal (IMAGE) ARC Centre of Excellence in Exciton Science Caption Scanning confocal microscope image of a single mixed-halide perovskite crystal showing emission from mixed (green) and segregated (red) regions. The central region is exposed to intense light, which causes the halide-ions in this region to mix, generating green (540-570 nm) fluorescence. The red emission (>660 nm) is from phase-segregated perovskite driven by the low-intensity confocal microscope scanning laser. Credit ARC Centre of Excellence in Exciton Science Usage Restrictions Credit: ARC Centre of Excellence in Exciton Science License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.