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Mg Layers (mg + layer)

Distribution by Scientific Domains
Physics and Astronomy100%

Selected Abstracts

Photoluminescence and Hall studies of GaN:Fe and (Ga,Fe)N:Mg layers

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 1 2007
M. Wegscheider
Abstract Temperature dependent photoluminescence (PL) in the ultraviolet (UV) regime and Hall measurements at room temperature have been performed on Metal-Organic-Chemical-Vapour-Deposition (MOCVD) grown GaN:Fe and (Ga,Fe)N:Mg layers. PL measurements were employed in order to study the dopants' influence on the near-band edge excitonic emission and their tendency to provoke the formation and suppression of defects or incorporation of impurities. For their identification and for the understanding of the PL spectra the evaluation of the free carrier concentrations via Hall measurements were necessary. Depending on the iron concentration of the (Ga,Fe)N layers, the near-band edge emission goes through two different stages: at low Fe-concentration no excitonic emission can be seen whereas with higher doping levels, excitonic features develop. The (Ga,Fe)N films exhibit n-type behaviour. The Mg codoped samples show strong Mg and defect related luminescence bands, whose occurrence and intensity also strongly depends on whether high or low Fe concentration is present. The (Ga,Fe)N:Mg layers were semi insulating. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Study of the activation process of Mg dopant in GaN:Mg layers

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 3 2006
B. Paszkiewicz
Abstract GaN:Mg layers with different concentration of Mg dopant were grown by metalorganic vapour phase epitaxy. The incorporation of Mg was verified by secondary ion mass spectroscopy. In order to dissociate Mg-related complexes and thus electrically activate the acceptor dopant, the as-grown layers were annealed in pure N2 at ,800 °C for 30 minutes. The influence of the post-growth annealing on the layer properties was studied by photoluminescence (PL) and impedance spectroscopy. Impedance spectroscopy measurement showed that the annealed samples reveal higher charge concentrations and lower sheet resistance. Moreover, the relaxation time of hole traps decreased in annealed samples by one order of magnitude compared to as-grown samples. The changes in the electrical properties have been correlated with the changes in the PL spectra. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]