A novel edge-incident wavelength modulation transmittance spectroscopy (WMTS) technique combined with conventional photoluminescence (PL) measurements is developed to investigate the optical properties of two InGaN/GaN multiple-quantum-well (MQW) structures in the temperature range between 15 and 300 K. The S-shaped PL shift with temperature and the InGaN A1 (LO) phonon replicas were observed in temperature-dependent PL measurements. It can be explained by the localization of self-organized InN clusters within the InGaN layers. Besides, we for the first time use the edge-incident WMTS technique to eliminate the multireflection interference effect, which in the conventional transmittance or absorption measurements usually causes spectral oscillation to make the optical features difficult to identify. The excitonic transitions and absorption edge of GaN layers have been revealed clearly. Compared to an envelope-function calculation taking into account the quantum confined Stark effect (QCSE), the origins of these spectral features are assigned. The parameters that describe the temperature dependence of the excitonic transition energies are also evaluated.
|Number of pages||5|
|Journal||Physica Status Solidi (C) Current Topics in Solid State Physics|
|Publication status||Published - 2006 Jul 31|
|Event||6th International Conference on Nitride Semiconductors, ICNS-6 - Bremen, Germany|
Duration: 2005 Aug 28 → 2005 Sep 2
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics