Group-IIIA versus IIIB Delafossites: Electronic Structure Study
First-principles density-functional theory calculations reveal significantly different behavior between group-IIIA and IIIB delafossites CuMO{sub 2}. The group-IIIA delafossites have indirect band gaps with large differences between the direct and indirect band gaps. However, this difference is small for the group-IIIB delafossites: only 0.22 eV for CuScO{sub 2} and it diminishes further for CuYO{sub 2} and CuLaO{sub 2}. Also, whereas group IIIA prefers rhombohedral stacking, group IIIB stabilizes in hexagonal structures. We further find that CuScO{sub 2} has the highest calculated fundamental band gap among all the delafossite oxides. In addition, CuLaO{sub 2} is found to have a direct band gap. These differences are explained by the different atomic configurations between the group-IIIA and IIIB elements. Our understanding of these delafossites provides general guidance for proper selection of delafossites for suitable applications in optoelectronic devices.
- Research Organization:
- National Renewable Energy Lab. (NREL), Golden, CO (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC36-08GO28308
- OSTI ID:
- 1021245
- Journal Information:
- Physical Review. B, Condensed Matter and Materials Physics, Vol. 80, Issue 3, 2009; Related Information: Article No. 035205
- Country of Publication:
- United States
- Language:
- English
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