Excitonic properties and band alignment in lattice-matched ZnCdSe/ZnMgSe multiple-quantum-well structures

Lattice-matched Zn0.85Cd0.15Se/Zn0.74Mg0.26Se multiple-quantum-well structu res were obtained on GaAs(001) using graded-composition InyGa1-yAs layers t o match the II-VI lattice parameter to the III-V substrate. Cross-sectional transmission electron microscopy studies show that the effect of the cross hatch pattern of the InyGa1-yAs surface is limited to long-period coherent undulations of quantum well and barrier layers. Optical measurements of the excitonic properties as a function of well thickness, complemented by self -consistent calculations of the transition energies, indicate good quantum confinement in the well, with a 68% conduction band contribution to the 0.4 82 eV band gap difference. (C) 2001 American Institute of Physics.