Determination of critical layer thickness in InxGa1minus;xAs/GaAs heterostructures by xhyphen;ray diffraction

摘要

The critical thicknesshcof strained InxGa1minus;xAs layers grown by molecular beam epitaxy on GaAs(100) substrates is determined by doublehyphen;crystal xhyphen;ray diffraction for 0.07le;xle;0.25. The experimental results are in good agreement with critical thicknesses calculated from the energy balance model of R. People and J. C. Bean lsqb;Appl. Phys. Lett.47, 322 (1985)rsqb; but differ from prior photoluminescence measurements ofhcfor this material. Beyond the critical thickness the transition from the strained to the relaxed state occurs more rapidly as the In concentration and hence the lattice mismatch increases.