| Autor: |
Han, B., Mishra, K. C., Raukas, M., Klinedinst, K., Tao, J., Talbot, J. B. |
| Předmět: |
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| Zdroj: |
Journal of The Electrochemical Society; Jan2007, Vol. 154 Issue 1, pJ44-J52, 9p, 1 Diagram, 1 Chart, 1 Graph |
| Abstrakt: |
The preparation of powder samples of aluminum nitride activated by dysprosium, AlN/Dy3+, was achieved for the first time using a low-temperature, solution-based approach. Aqueous solutions of aluminum and dysprosium nitrates was first converted to hydroxides and then to ammonium-metal hexafluorides (Al1-xDyx(NH4)3F6. Finally, this complex ammonium salt was converted to finely divided powders of Al1-xDyxN via a pyrolysis reaction in a high-purity ammonia flow inside a tubular quartz furnace at 900°C. The phase purity and crystallinity of the material were determined using X-ray diffraction and energy dispersive spectroscopy. The intraconfigurational f-f transitions of Dy3+ were investigated using photoluminescence (PL) and photoluminescence excitation (PLE) measurements. The excited states of Dy3+ in this large-gap nitride were identified from a careful analysis of PL and PLE results. It was also observed from the PLE measurements that the Dy3+ ions in this host are excited through energy transfer from both the excited state of the host lattice and defects. Measurements using site-selective spectroscopy suggest multiple sites for Dy3+ ions in AlN. A theoretical model describing the excitation process and saturation of excited states of Dy3+ at higher intensity of the exciting radiation is also proposed. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Supplemental Index |
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