Increased p-type conductivity in GaNxSb1-x, experimental and theoretical aspects
| Autor: | M. J. Ashwin, Jan Kujala, Filip Tuomisto, Ilja Makkonen, Jonatan Slotte, Natalie Segercrantz, Tim D. Veal |
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| Přispěvatelé: | Department of Applied Physics, Aalto-yliopisto, Aalto University |
| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
Materials science
Band gap ALLOYS ta221 Analytical chemistry General Physics and Astronomy AUGMENTED-WAVE METHOD SEMICONDUCTORS Positron annihilation spectroscopy Electrical resistivity and conductivity MOLECULAR-BEAM EPITAXY Vacancy defect UNDOPED GALLIUM ANTIMONIDE ANNIHILATION ta218 QC Valence (chemistry) ta214 ta114 Positron Lifetime Spectroscopy GROWN GANAS POSITRON LIFETIME SPECTROSCOPY BAND-GAP REDUCTION PHOTOLUMINESCENCE Atomic physics Molecular beam epitaxy Doppler broadening |
| ISSN: | 0021-8979 |
| Popis: | The large increase in the p-type conductivity observed when nitrogen is added to GaSb has been studied using positron annihilation spectroscopy and ab initio calculations. Doppler broadening measurements have been conducted on samples of GaNxSb1-x layers grown by molecular beam epitaxy, and the results have been compared with calculated first-principle results corresponding to different defect structures. From the calculated data, binding energies for nitrogen-related defects have also been estimated. Based on the results, the increase in residual hole concentration is explained by an increase in the fraction of negative acceptor-type defects in the material. As the band gap decreases with increasing N concentration, the ionization levels of the defects move closer to the valence band. Ga vacancy-type defects are found to act as positron trapping defects in the material, and the ratio of Ga vacancy-type defects to Ga antisites is found to be higher than that of the p-type bulk GaSb substrate. Beside Ga vacancies, the calculated results imply that complexes of a Ga vacancy and nitrogen could be present in the material. (C) 2015 AIP Publishing LLC. |
| Databáze: | OpenAIRE |
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