Resolution of Discrete Excited States in InxGa1-xN Multiple Quantum Wells Using Degenerate Four-Wave Mixing
Kundys, D O, Wells, J P, Andreev, A D, Hashemizadeh, S A, Wang, T, Parbrook, P J, Fox, A M, Mowbray, D J and Skolnick, M S (2006) Resolution of Discrete Excited States in InxGa1-xN Multiple Quantum Wells Using Degenerate Four-Wave Mixing Physical Review B, 73 (16). ISSN 1098-0121
Official URL: http://dx.doi.org/10.1103/PhysRevB.73.165309
We report on two pulse, degenerate four-wave mixing (DFWM) measurements on shallow InxGa1-xN/GaN multiquantum wells (MQWs) grown on sapphire substrates. These reveal pulse length limited signal decays. We have found a 10:1 resonant enhancement of the DFWM signal at the excitonic transition frequencies which thereby give a sharp discrimination of the discrete excitonic contributions within the featureless distribution seen in absorption spectra. The exciton resonances have peak positions, which yield good overall agreement with a full k(.)p model calculation for the quantum well (QW) energy levels and optical transition matrix elements. InxGa1-xN/GaN MQWs generally exhibit strongly inhomogeneously broadened excitation spectra due to indium fluctuation effects; this approach therefore affords a practical method to extract information on the excited excitonic states not available previously.
Published in Physical Review B, Vol. 73, Iss. 16. Copyright 2006 American Physical Society.
|Divisions:||Faculty of Engineering and Physical Sciences > Physics|
|Deposited By:||Mr Adam Field|
|Deposited On:||27 May 2010 15:05|
|Last Modified:||20 Sep 2012 13:10|
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