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We present systematic studies of the alloy disorder dependence of line-widths in InGaAs/GaAs strained-layer quantum wells grown by molecular beam epitaxy using both photoluminescence and optical absorption. Indium composition of the samples under investigation ranged from 0.1 to 0.2. The effects of well-size variation were measured and analyzed, In all cases we were able to observe the exciton transition and the increase of linewidths with a content and well size. In addition, variations of the lineshape were found with the increasing temperature in optical absorption. The experimental data by the virtual crystal approximation and are analysed.The results obtained from this study show the alloy disorder is the dominant mechanism for line broadening at a low temperature, which is in contrast with the case of GaAs/AlGaAs structure, where the principal broadening mechanism is the interface roughness at the low temperature. This information is important for optimizing the crystal-growth condition and improving the quality of crystal-grown structures.
We present systematic studies of the alloy disorder dependence of line-widths in InGaAs / GaAs strained-layer quantum wells grown by molecular beam epitaxy using both photoluminescence and optical absorption. Indium composition of the samples under investigation ranged from 0.1 to 0.2. The effects of well-size variation were measured and analyzed, In all cases we were able to observe the exciton transition and the increase of linewidths with a content and well size. In addition, variations of lineshape were found with the increasing temperature in optical absorption. The experimental data by the virtual crystal approximation and are analyzed. The results obtained from this study show the alloy disorder is the dominant mechanism for line broadening at a low temperature, which is in contrast with the case of GaAs / AlGaAs structure, where the principal broadening mechanism is the interface roughness at the low temperature. This information is important for optimizing the crystal-growth co ndition and improving the quality of crystal-grown structures.