Super-Thin Material (IMAGE) University at Buffalo Caption A scanning electron microscope image shows tungsten disulfide grown on a sapphire substrate (light area). The medium gray area shows monolayer tungsten disulfide and the dark area shows multilayer tungsten disulfide. After growing the tungsten disulfide on the sapphire, researchers transfer it onto europium sulfide. Credit Credit: Chuan Zhao / University at Buffalo Usage Restrictions This image may only be used in news reports discussing the research in the associated press release. 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.