Reflectivity studies of the strain dependence on E0 and E0+ Delta 0 excitonic transitions in ZnSe/GaAs.

Abstract

The optical properties of ZnSe epilayers grown on (100) GaAs are greatly influenced by residual stress. Reflectance spectra of ${\mathit{E}}_{0}$ (light-hole and heavy-hole) and ${\mathit{E}}_{0}$+${\mathrm{\ensuremath{\Delta}}}_{0}$ excitonic transitions for layers thicker than 1 \ensuremath{\mu}m allow the determination of the ratio of the shear deformation potential (b) to the hydrostatic deformation potential (a). The value of the spin-orbit interaction (${\mathrm{\ensuremath{\Delta}}}_{0}$) is also determined for each layer that suffers two-dimensional tensile stress due to the difference in the thermal-expansion coefficients. The polarization characteristics of excitonic transitions reveal the misorientation of the layer and allow unambiguous identification of the light-hole and heavy-hole excitonic transitions.