Zhang, Hui Formamidinium Incorporation into Compact Lead Iodide for Low Band Gap Perovskite Solar Cells with Open-Circuit Voltage Approaching the Radiative Limit. [electronic resource] - ACS applied materials & interfaces Mar 2019 - 9083-9092 p. digital Publication Type: Journal Article ISSN: 1944-8252 Standard No.: 10.1021/acsami.8b20899 doi