Local Structure Around Te in Heavily Doped GaAs:Te using X-Ray Absorption Fine Structure |
| A. Pietnoczkaa, R. Bacewicza, T. Slupinskib, J. Antonowicza, Su-Huai Weic
a Warsaw University of Technology, Faculty of Physics, Koszykowa 75, Warszawa 00-662, Poland b Warsaw University, Faculty of Physics, Hoża 69, Warszawa 00-681, Poland c National Renewable Energy Laboratory (NREL), 1617 Cole Blvd, Golden, CO 80401, United States |
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| The annealing of heavily doped GaAs:Te can significantly change the free electron concentration in a reversible manner. These changes of electrical properties are accompanied by the structural changes of GaAs:Te solid solution. We used X-ray Absorption Fine Structure at K-edge of tellurium to determine local changes around Te atoms for different states of the GaAs:Te crystals caused by the annealing corresponding to different electron concentrations. The best EXAFS fit for the samples with high electron concentration was obtained for the substitutional TeAs model with elongated Te-Ga bonds (as compared to the As-Ga distance). For the samples in the low concentration state the best fit was for the pairs of Te atoms forming a rhombohedral symmetry double-DX centre, with the proportional admixture of the substitutional tellurium |
| DOI: 10.12693/APhysPolA.121.879 PACS numbers: 61.05.cj, 61.72.uj |