Abstract
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.
Original language | English |
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Article number | 165309 |
Journal | Physical Review B: Condensed Matter and Materials Physics |
Volume | 73 |
Issue number | 16 |
DOIs | |
Publication status | Published - 11 Apr 2006 |
Keywords
- SEMICONDUCTORS
- GAN