| Autor: |
Othonos, Andreas, Zervos, Matthew, Christofides, Constantinos |
| Předmět: |
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| Zdroj: |
Journal of Applied Physics; Dec2010, Vol. 108 Issue 12, p124319, 8p, 1 Black and White Photograph, 5 Charts, 11 Graphs |
| Abstrakt: |
GaN nanowires (NWs) with a hexagonal wurtzite crystal structure, diameters of 50 nm and lengths of 10 μm have been obtained from postgrowth nitridation of monoclinic β-Ga2O3 NWs using NH3 between 700-1090 °C. The conversion of β-Ga2O3 to GaN NWs has been investigated in a systematic way by varying the temperature, gas flows and nitridation times using Ar or N2:10% H2. We find that nitridation is most effective at temperatures ≥900 °C using NH3 with N2:10% H2 which promotes the efficient conversion of β-Ga2O3 to GaN, resulting into the enhancement of the band edge emission, suppression of the broad-band photoluminescence (PL) related to oxygen defects and the appearance of red emission due to deep-acceptorlike states. The gradual evolution of the PL spectra from that of β-Ga2O3 to GaN exhibited a clear, systematic dependence on the nitridation temperature and gas flows and the band to band emission lifetime which was found to be τ≈0.35 ns in all cases. In contrast the nitridation of β-Ga2O3 NWs using NH3 and Ar is less effective. Therefore, H2 is essential in removing O2 and also effective since it lead to the complete elimination of the β-Ga2O3 NWs at 1000 °C in the absence of NH3. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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