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N-Composition and Pressure Dependence of the Inter Band Transitions of Ga(N,As)/GaAs Quantum Wells |
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| Authors: | H Grüning P J Klar W Heimbrodt J Koch W Stolz A Lindsay |
| Institution: | 1. Department of Physics and Material Sciences Center , Philipps-University , Renthof 5, Marburg , D-35032 , Germany Phone: ++49 (0)6421 2821354 Fax: ++49 (0)6421 2821354 E-mail: heiko.gruening@physik.uni-marburg.de;2. Department of Physics and Material Sciences Center , Philipps-University , Renthof 5, Marburg , D-35032 , Germany;3. Department of Physics , University of Surrey , Guildford , Surrey , GU2 5XH , United Kingdom |
| Abstract: | A series of GaN x As 1 m x /GaAs quantum well structures with well widths of about 20 nm and x varying between 1% and 3.5% has been grown by metal-organic vapour phase epitaxy. We have studied the evolution of the quantum well states under hydrostatic pressure up to 20 kbar at 300 K by photomodulated reflectance (PR) spectroscopy. The energy positions of the quantum well transitions have been obtained by fitting the PR spectra. The pressure dependence of the allowed heavy-hole transitions e n hh n decreases with increasing n . This directly reflects the strong non-parabolic dispersion of the conduction band originating from the interaction of the N-impurity level with the bands of the GaAs host. The fitted energy positions and their pressure dependence can be well described by a 10 band k.p model. The observed splitting between the lowest light-hole and heavy-hole transitions are in agreement with a type I band alignment. |
| Keywords: | Ganas Quantum Wells Hydrostatic Pressure Interband Transitions |