Regensburg 2013 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 72: Focus Session: Extended defects in semi- and nonpolar GaN I
HL 72.7: Talk
Thursday, March 14, 2013, 12:30–12:45, H13
Optical properties of MBE grown cubic AlGaN/GaN double quantum well structures — •Tobias Wecker, Christian Mietze, Dirk Reuter, and Donat J. As — Department of Physics, University of Paderborn, Warburger Str. 100, 33098 Paderborn, Germany
The spatial separation of electrons and holes in AlxGa1−xN/GaN quantum well structures due to polarization effects can be avoided by growing cubic quantum well samples in the (001) direction. Therefore the optical recombination efficiency in quantum well structures can be increased compared to the hexagonal phase with their strong spontaneous polarization along the hexagonal c-axis [1].
Cubic AlxGa1−xN/GaN double heterostructures were grown on 3C-SiC(001) substrates by radio-frequency plasma-assisted molecular beam epitaxy. The coupling of the two quantum wells with varying barrier thicknesses was investigated by photoluminescence spectroscopy at room temperature as well as low temperature. The good crystal quality of the samples is demonstrated by high resolution X-ray diffraction.
The strain effects for different Al contents due to the pseudomorphically strained AlGaN barriers were investigated employing photoluminescence spectroscopy and X-Ray diffraction reciprocal space maps around the (113) reflection.
[1] D.J. As, K. Lischka, "Nonpolar cubic III-nitrides", In: Henini M, "Molecular Beam Epitaxy: From research to mass production", Elsevier Inc., 2013, p.203-215, ISBN: 9780123878397