| Autor: |
Veal, T. D., Piper, L. F. J., Phillips, M. R., Zareie, M. H., Lu, Hai, Schaff, W. J., McConville, C. F. |
| Zdroj: |
Physica Status Solidi (A) - Applications and Materials Science; January 2006, Vol. 203 Issue: 1 p85-92, 8p |
| Abstrakt: |
Electron tunnelling spectroscopy has been used to investigate quantized levels in electron accumulation layers at InGaN surfaces. The tunnelling spectra exhibit a plateau in the normalized conductance which widens with increasing Ga-content, corresponding to the band gap of InGaN. The measured InxGa1–xN band gaps (between ∼0.65 eV for x = 1 and 1.8 eV for x = 0.43) are consistent with the band gaps determined by previous optical absorption and cathodoluminescence spectroscopy. Additional structures in the spectra reflect the two-dimensional electronic subbands in the surface quantum well. The subband energies depend on Ga-content, bulk doping level and the resultant shape of the surface potential well. The tunnelling spectra are compared with calculations of the potential well, the charge-profile and the subband energies. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) |
| Databáze: |
Supplemental Index |
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