| Autor: |
Wolos, A., Kaminska, M., Palczewska, M., Twardowski, A., Liu, X., Wojtowicz, T., Furdyna, J.K. |
| Předmět: |
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| Zdroj: |
Journal of Applied Physics; 7/1/2004, Vol. 96 Issue 1, p530-533, 4p, 3 Graphs |
| Abstrakt: |
We report the results of optical absorption measurements on Ga1-xMnxAs layers grown by low-temperature molecular beam epitaxy. In the paramagnetic layers grown at very low temperatures (below 250 °C) the experiments reveal an absorption band at 1.2 eV arising from the presence of neutral arsenic antisites, AsGa. From the magnitude of the absorption we determine the concentration of AsGa to be between 4×1019 and 8×1019 cm-3 in these paramagnetic samples. These values are typical for GaAs specimens grown below 250 °C. Extrapolating the AsGa concentration from low-temperature-grown GaAs to Ga1-xMnxAs, we determine the concentration of this defect in ferromagnetic Ga1-xMnxAs layers grown at temperatures above 250 °C as 1×1019 down to 1×1018 cm-3. We conclude that the compensating role of arsenic antisites in Ga1-xMnxAs becomes gradually less important with increasing growth temperature. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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