Temperature Dependent Exciton Shifts in AlGaAs Alloys
Abstract
We report a measurement of the variation of the peak energy of the excitonic transition for AlGaAs alloys as a function of temperature using photoluminescence (PL) spectroscopy. The samples were grown by MBE and the temperature measurements were performed between 1.4 and 150K. The Al concentration varied between 5 and 30% We find that the energy excitonic transition increases slightly as a function of temperature until about 30K after which it decreases with temperature, exhibiting Varshni-type behavior. The magnitude of the shift is found to depend on the Al concentration as does the PL linewidth. The temperature dependent results will be discussed in terms of (1) Alloy fluctuation induced exciton locallization model and (2) A free exciton model
- Publication:
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APS March Meeting Abstracts
- Pub Date:
- March 2001
- Bibcode:
- 2001APS..MARX30004J