Electron irradiation enhanced luminescence in GaAs1-xSbx/GaAs quantum wells
Abstract
Quantum wells of GaAs1-xSbx/GaAs were grown on (100) GaAs substrates by metalorganic vapor phase deposition. The composition x and the thickness of the quantum well layers were deduced from simulations of their X-ray rocking curves. Narrow peaks and the appearance of pendellosung fringes show that relaxation of the wells through misfit dislocation is negligible for x < 0.2. Relaxation gradually becomes important for larger x. Relaxation is also reflected through the surface morphology of the thin capping GaAs barrier layer; it often leads to the appearance of long ridges on the surface, possibly as a result of enhanced local growth rate, otherwise only mono-atomic surface steps are seen by atomic force microscopy. Cathodoluminescence studies of the quantum wells reveal that the intensity of light emission from the wells first grow to a maximum and the falls when irradiated by an electron beam under different conditions. The evolution of the luminescent intensity of all the quantum wells studied follows a universal empirical equation, regardless of the degree of relaxation. These results suggest that the possibly underlying cause of irradiation-enhanced defect reactions may find potential application in improving the radiative efficiency of quantum well devices.
- Publication:
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APS March Meeting Abstracts
- Pub Date:
- March 2004
- Bibcode:
- 2004APS..MARD36013L