QUANTUM CONFINEMENT EFFECTS IN STRAINED SILICON-GERMANIUM ALLOY QUANTUM-WELLS

We report the first detailed study of quantum confinement shifts of band-edge photoluminescence energies in Si/strained Si(1-x)Ge(x)/Si single quantum wells. A quantum confinement energy of up to 45 meV has been observed for quantum wells as small as 33 angstrom in width. The experimental results are in good agreement with a calculation of the hole confinement energies. The hole energy levels in quantum wells were obtained by numerically solving effective-mass equations with proper matching boundary conditions at interfaces using a 6 X 6 Luttinger-Kohn Hamiltonian. Both strain and spin-orbit interactions were included in the calculation.