Chemically Switchable Ultraviolet Luminescence (image) Drexel University Share Print E-Mail Caption In the presence of a water molecule on its surface, lanthanum aluminate film on a strontium titanate crystal emits ultraviolet light from its interior. (Illustration not to scale). Credit Drexel University Usage Restrictions None Share Print E-Mail 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.