| 1. |
- Paskova, Tanja, et al.
(författare)
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Influence of growth rate on the structure of thick GaN layers grown by HVPE
- 2000
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Ingår i: Journal of Crystal Growth. - 0022-0248 .- 1873-5002. ; 208:1, s. 18-26
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Tidskriftsartikel (refereegranskat)abstract
- Thick GaN films grown by hydride vapour phase epitaxy have been investigated by cathodoluminecsence, X-ray diffraction, and photoluminescence. Cross-sectional studies of thick GaN layers grown on sapphire without buffers reveal three zones: a highly disordered interface region, a columnar defective region and a good quality main region of the layer. The influence of the highly doped columnar region on the surface morphology and crystal structure of the layers has been studied. We show that the columnar region influences the material quality more strongly in thinner films. Thicker layers exhibit improved morphology with lower surface pit density and better crystal quality shown in photoluminescence and X-ray diffraction spectra. The relationship between the near-interface columnar structures and surface pits is revealed. A strong effect of the growth rate on the structure of thick layers is found. The results suggest that GaN layers with optimum crystalline quality may be obtained by varying the growth rate during growth.
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| 2. |
- Buyanova, Irina, 1960-, et al.
(författare)
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Optical and electronic properties of GaNAs/GaAs structures
- 2000
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Konferensbidrag (refereegranskat)abstract
- We review our recent results from studies of electronic properties of GaNAs/GaAs structures with low nitrogen content, by photoluminescence (PL), PL excitation, time-resolved PL spectroscopies as well as optically detected magnetic resonance (ODMR) and cyclotron resonance (ODCR) studies. The issues to be addressed include key material-related properties and fundamental electronic parameters of the GaNAs alloy, relevant to device applications, such as identification of the dominant recombination processes in the alloy, compositional dependence of the electron effective mass and band alignment in the GaNAs/GaAs heterostructures.
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