Regensburg 2000 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 27: Poster II: SiC (1-7), Ultrakurzzeitdynamik (8-15), Halbleiterlaser (16-20), GaN (21-38), III-V Halbleiter (39-56), Photovoltaik (57-64), Störstellen (65-68), Tern
äre Halbleiter (69-70)

HL 27.5: Poster

Mittwoch, 29. März 2000, 14:00–19:00, A

Infrared absorption spectra of 4H silicon carbide — •C. Q. Chen¹, R. Helbig¹, F. Engelbrecht¹, and J. Zeman² — ¹Institute of Applied Physics, University of Erlangen-Nürnberg, Germany — ²High Magnetic Field Laboratory, Grenoble Cedex 9, France

We performed infrared absorption measurements on 4H-SiC samples with the polarizations of E  ∥  c and E ⊥ c at 8, 85 and 300K. From the strong temperature dependence of the absorption lines, electronic transitions are separated from vibronic transitions. The electronic transition lines between 300 and 500cm⁻¹ are assigned to the shallow nitrogen donor. The electronic transitions of the shallow nitrogen donor are found to be polarization dependent, which results from the C_3V site symmetry of nitrogen donor in 4H-SiC. Zeeman spectra show no linear Zeeman splitting and only a diamagnetic shift of electronic transitions in Faraday configuration (c ∥ B ∥ k). This is consistent with an effective mass tensor of three different diagonal components in 4H-SiC.