Atomic Structure and Electrical Activity of Grain Boundaries and Ruddlesden-Popper Faults in Cesium Lead Bromide Perovskite
- Washington Univ., St. Louis, MO (United States)
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Univ. of Missouri, Columbia, MO (United States)
To evaluate the role of planar defects in lead-halide perovskites—cheap, versatile semiconducting materials—it is critical to examine their structure, including defects, at the atomic scale and develop a detailed understanding of their impact on electronic properties. In this study, postsynthesis nanocrystal fusion, aberration-corrected scanning transmission electron microscopy, and first-principles calculations are combined to study the nature of different planar defects formed in CsPbBr3 nanocrystals. Two types of prevalent planar defects from atomic resolution imaging are observed: previously unreported Br-rich [001](210)Σ5 grain boundaries (GBs) and Ruddlesden–Popper (RP) planar faults. The first-principles calculations reveal that neither of these planar faults induce deep defect levels, but their Br-deficient counterparts do. It is found that the Σ5 GB repels electrons and attracts holes, similar to an n–p–n junction, and the RP planar defects repel both electrons and holes, similar to a semiconductor–insulator–semiconductor junction. Finally, the potential applications of these findings and their implications to understand the planar defects in organic–inorganic lead-halide perovskites that have led to solar cells with extremely high photoconversion efficiencies are discussed.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE
- Grant/Contract Number:
- AC05-00OR22725
- OSTI ID:
- 1493984
- Alternate ID(s):
- OSTI ID: 1484312
- Journal Information:
- Advanced Materials, Journal Name: Advanced Materials Journal Issue: 4 Vol. 31; ISSN 0935-9648
- Publisher:
- WileyCopyright Statement
- Country of Publication:
- United States
- Language:
- English