Electronic Excitations in B12As2 and their Temperature Dependence by Vacuum Ultraviolet Ellipsometry
The dielectric response function of epitaxial B{sub 12}As{sub 2} films on 4H-SiC was determined at room temperature and at 10 K in the spectral region of 3.6-9.8 eV, i.e., in the vacuum ultraviolet (VUV) spectral region, by synchrotron ellipsometry. The experimental dielectric function was simulated with the critical point parabolic band model. The parameters of the dispersive structures were derived by numerical fitting of the experimental data to the proposed model. New high energy optical transitions are resolved at 5.95, 7.8 and 8.82 eV and their lineshape and origin are discussed. The temperature dependence of the critical point energies and transition strengths was determined, and the excitonic effect is considered.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States)
- Sponsoring Organization:
- USDOE SC OFFICE OF SCIENCE (SC)
- DOE Contract Number:
- DE-AC02-98CH10886
- OSTI ID:
- 1041867
- Report Number(s):
- BNL-97545-2012-JA; JCOMEL; TRN: US201212%%278
- Journal Information:
- Journal of Physics. Condensed Matter, Vol. 22, Issue 39; ISSN 0953-8984
- Country of Publication:
- United States
- Language:
- English
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