Fig. 2 (IMAGE) Science China Press Caption Morphology and crystallinity of perovskite films before and after different concentration (NH4)2C2O4* H2O treatment. Credit ©Science China Press Usage Restrictions Use with credit. 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.