Gold Nanorods (IMAGE) Washington University in St. Louis Caption This image shows how electrons in the gold nanorods get excited when exposed to light, then are absorbed into a thin film of zinc oxide, changing the properties of the composite from a metal into a semiconductor. Credit: ACS Applied Materials & Interfaces. Credit Washington University 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.