Enhancement of Intersubband Absorption in GaInN/AlInN Quantum Wells
G. Cywiński a, C. Skierbiszewski a, M. Siekacz a, M. Kryśko a, A. Feduniewicz-Żmuda b, M. Gladysiewicz c, R. Kudrawiec c, J. Misiewicz c, L. Nevou d, N. Kheirodin d and F.H. Julien d
a Institute of High Pressure Physics, Polish Academy of Sciences, Sokołowska 29/37, 01-142 Warsaw, Poland
b TopGaN Ltd, 01-142 Warsaw, Poland
c Institute of Physics, Wrocław University of Technology, 50-370 Wrocław, Poland
d Action OptoGaN, Institut d'Electronique Fondamentale, UniversitéParis-Sud, UMR 8622, CNRS, 91405 Orsay Cedex, France
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Received: 7 06 2008;
GaInN/AlInN multiple quantum wells were grown by RF plasma-assisted molecular beam epitaxy on (0001) GaN/sapphire substrates. The strain-engineering concept was applied to eliminate cracking effect and to improve optical parameters of intersubband structures grown on GaN substrates. The high quality intersubband structures were fabricated and investigated as an active region for applications in high-speed devices at telecommunication wavelengths. We observed the significant enhancement of intersubband absorption with an increase in the barrier thickness. We attribute this effect to the better localization of the second electron level in the quantum well. The strong absorption is very important on the way to intersubband devices designed for high-speed operation. The experimental results were compared with theoretical calculations which were performed within the electron effective mass approximation. A good agreement between experimental data and theoretical calculations was observed for the investigated samples.
DOI: 10.12693/APhysPolA.114.1093
PACS numbers: 78.30.Fs, 78.67.De, 68.65.Fg, 73.21.Fg, 81.15.Hi