ferrocene-based metallic compound (IMAGE) City University of Hong Kong Caption The top picture shows the molecular structure of ferrocene-based metallic compound (FcTc2) and its application in perovskite solar cells. The bottom picture shows the working mechanism of the ferrocene-based metallic compound. Credit Z. Li, B. Li, X. Wu et al., DOI:10.1126/science.abo0039 Usage Restrictions Image must be used with appropriate caption and 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.