Optical study of segregation effects on the electronic properties of molecular-beam-epitaxy grown (In,Ga)As/GaAs quantum wells

Indium segregation in ${\mathrm{In}}_{\mathrm{x}}$ ${\mathrm{Ga}}_{1\mathrm{-}\mathrm{x}}$ As/GaAs (0.3${\mathrm{Q}}_{\mathrm{c}}$ is found to be independent of indium composition x between 0.2 and 0.5 (${\mathrm{Q}}_{\mathrm{c}}$ =0.64±0.01). The exciton wave function is calculated using a variational technique involving a transfer-matrix formalism to study the influence of potential shape on excitonic properties. Only a slight increase in oscillator strength with In segregation is observed for the fundamental excitonic transition.