Excitonic Diamagnetic Shifts and Magnetic Field Dependent Linewidths in AlxGa1-xAs Alloys
Abstract
We report measurements of both the diamagnetic shifts and the linewidths of excitonic transitions in Al(x)Ga(1-x)As alloys as a function of Al concentration and magnetic field at 1.4 K using photoluminescence spectroscopy. The magnetic field was varied from 0 to 13 tesla and Al composition in our samples ranged from 0 to 30%. The samples were grown on GaAs substrates oriented along 001 direction using molecular beam epitaxy at 590 deg C. We find that for a given value of alloy composition, both the diamagnetic shift and excitonic linewidth increase as a function of magnetic field. To explain our experimental data we propose that the excitons are localized in a very specific manner. To simulate this localization, we assume that the exciton reduced mass is effectively increased and is obtained by using the alloy dependent heavy-hole mass along (001) direction treated isotropically. The calculated values of the variations of the diamagnetic shift and excitonic linewidth as a function of magnetic field obtained using this model agree very well with those reported here.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2002
- Accession Number
- ADP012631
Entities
People
- E. D. Jones
- G. Coli
- J. L. Reno
- K. K. Bajaj
Organizations
- Emory University