REFLECTIVITY STUDIES OF THE STRAIN DEPENDENCE ON E0 AND E0+DELTA-0 EXCITONIC TRANSITIONS IN ZNSE GAAS

The optical properties of ZnSe epilayers grown on (100) GaAs are greatly influenced by residual stress. Reflectance spectra of E0 (light-hole and heavy-hole) and E0 + DELTA-0 excitonic transitions for layers thicker than 1-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 (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.