Engelbrecht, F. and Zeman, J. and Wellenhofer, G. and Peppermüller, C. and Helbig, R. and Martinez, G. and Rössler, Ulrich (1997) Hydrostatic-pressure coefficient of the indirect gap and fine structure of the valence band of 6H-SiC. PHYSICAL REVIEW B, 56 (12). pp. 7348-7355. ISSN 0163-1829
Full text not available from this repository.Abstract
Photoluminescence measurements on 6H-SiC doped with nitrogen have been performed under hydrostatic pressure up to 50 kbar at low temperature (T=29+/-2 K). The observed emission lines S-0, R-0, P-0, S-02, and R-02 are due to excitons with holes from the A and B valence bands bound to the neutral nitrogen donor. The energy shift of the P-0 line under hydrostatic pressure is used to determine the linear pressure coefficient of the indirect gap of 6H-SiC, which yields 0.20 eV/Mbar. The energy difference between the emission lines S-02 (R-02) and S-0 (R-0) of 5.15+/-0.1 (5.08+/-0.1) meV gives the splitting Delta(AB) of the topmost valence bands. We employ nonrelativistic band-structure calculations within the density-functional theory based on the local-density approximation in order to calculate the pressure coefficient of the indirect band gap of 6H-SiC (together with those of 4H, 2H, and 3C-SiC as well as those of diamond, Si, and Ge) and the crystal field splitting of the valence band. The latter, together with the experimental splitting Delta(AB) of the topmost valence bands A and B is used to estimate the spin-orbit splitting of 6H-SiC to be about 7.7 meV. The calculated pressure coefficient shows good agreement with the experimental value.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | GROUND-STATE PROPERTIES; AB-INITIO CALCULATIONS; SILICON-CARBIDE; SIC POLYTYPES; ELECTRONIC-PROPERTIES; OPTICAL-PROPERTIES; RAMAN-SCATTERING; ABSORPTION; ENERGY; COMPRESSIBILITY |
| Subjects: | 500 Science > 530 Physics |
| Divisions: | Physics > Institute of Theroretical Physics > Alumni or Retired Professors > Group Ulrich Rössler |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 29 Mar 2023 08:44 |
| Last Modified: | 29 Mar 2023 08:44 |
| URI: | https://pred.uni-regensburg.de/id/eprint/50557 |
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