Monolayer Molybdenum Disulphide (MoS2) (IMAGE) Naval Research Laboratory Caption (Top) Illustration of a water molecule bonding at a sulfur vacancy in the MoS2 upon laser light exposure. (Bottom) Photoluminescence (PL) increase observed during laser light exposure in ambient. (Inset) Fluorescence image showing brightened regions spelling out 'NRL.' Credit (U.S. Naval Research Laboratory) Usage Restrictions None 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.