Some properties of strained InxGa1-xAs/Al0.28Ga0.72As quantum well structures studied using low temperature photoluminescence
✍ Scribed by S.F. Yoon; K. Radhakrishnan; H.M. Li
- Publisher
- Elsevier Science
- Year
- 1993
- Tongue
- English
- Weight
- 315 KB
- Volume
- 14
- Category
- Article
- ISSN
- 0749-6036
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✦ Synopsis
Low temperature photoluminescence measurements were carried out on pseudomorphlcally strained In (\mathrm{Ga}{1-\mathrm{A}} \mathrm{As}-\mathrm{Al} \mathrm{O}{0.28} \mathrm{Ga}{0.72} \mathrm{As}) ternary-on-ternary heterostructures grown by molecular beam epitaxy to investigate the change in the transition energy, inewidth and intensity as a function of InGaAs well thickness at two different indium compositions (x=0.10) and (x=0.15), respectively. Sharp exciton peaks as narrow as (4-6) (\mathrm{meV}) were observed from the InGaAs weils grown at (530^{\circ} \mathrm{C}) with (1 \mathrm{~min}) of growth interruption at the top and bottom heterointerfaces. The linewidth decreases as the well thickness is increased up to (300 \AA). In addition, there are signs of linewidth broadening and sharp decrease in the photoluminescence intensity at higher well thicknesses which may indicate the onset of plastic relaxation. Relatively small variations in the transition energy were observed at well thicknesses which are above the theoretical critical thickness as calculated by the Matthews-Blakeslee model [J. cryst. Growth (27(1974)) 118), suggesting the existence of a second critical thickness value, higher than the theoretical value. Good agreement between experimental and calculated transition energy vs well thickness data was obtained, from Which the conduction band of set (\triangle E{c} / \triangle E_{g}) was estimated to be (0.65 \pm 0.05) for (x=0.10-0.15), consistent with the results derived from other techniques.