PeLED_crop (IMAGE) Stanford University School of Engineering Caption Eight green perovskite LED substrates in Congreve’s lab glow as researchers shine ultraviolet light on them. Credit Sebastian Fernández / Stanford University Usage Restrictions Please use photo credit. License Original 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.