Linewidth analysis of the photoluminescence of ${\mathrm{In}}_{\mathit{x}}$${\mathrm{Ga}}_{1\mathrm{-}\mathit{x}}$As/GaAs quantum wells (x=0.09, 0.18, 1.0)

Photoluminescence measurements have been performed at low temperature in ${\mathrm{In}}_{\mathit{x}}$ ${\mathrm{Ga}}_{1\mathrm{-}\mathit{x}}$As/GaAs quantum wells with different well widths, L, and indium concentrations x. The dependence of the experimental linewidth of the heavy-hole–free-exciton recombination lines on L and x has been compared with existing models of interface and alloy disorder. It has been demonstrated that interface disorder has a crucial role at low L and high x. The estimated values of the interface-roughness size agree well with those found by different techniques.