Cubic inorganic perovskite CsPbI3 is a direct bandgap semiconductor, which is promising for optoelectronic applications, such as solar cells, light emitting diodes, and lasers. The intrinsic defects in semiconductors play crucial roles in determining carrier conductivity, the efficiency of carrier recombination, and so on. However, the thermodynamic stability and intrinsic defect physics are still unclear for cubic CsPbI3. By using the first-principles calculations, we study the thermodynamic process and find out that the window for CsPbI3 growth is quite narrow and the concentration of Cs is important for cubic CsPbI3 growth. Under Pb-rich conditions, VPb and VI can pin the Fermi energy in the middle of the bandgap, which results in a low carrier concentration. Under Pb-poor conditions, VPb is the dominant defect and the material has a high concentration of hole carriers with a long lifetime. Our present work gives an insight view of the defect physics of cubic CsPbI3 and will be beneficial for optoelectronic applications based on cubic CsPbI3 and other analogous inorganic perovskites.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This work was financially supported by the National Natural Science Foundation of China (Nos. 11504169, 61575094, 61664003, and 21673118), the National Basic Research Program of China (No. 2015CB932200), and the Natural Science Foundation of the Higher Education Institutions of Jiangsu Province, China (No. 16KJB150018). This work was also sponsored by the Qing Lan Project. For computer time, this research used the resources of the Supercomputing Laboratory at King Abdullah University of Science & Technology (KAUST) in Thuwal, Saudi Arabia.