Xu Yang, University of Groningen (IMAGE) University of Groningen Caption This is Ph.D. student Xu Yang, first author of the study. He is part of the Zernike Institute for Advanced Materials, University of Groningen. Credit X. Yang / University of Groningen Usage Restrictions With credit 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.