Sandwich structure (IMAGE) ARC Centre of Excellence in Exciton Science Caption A graphical representation of the proposed 2D perovskite 'sandwich' structure. Credit Exciton Science Usage Restrictions Credit: Exciton Science 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.