Visible Luminescence of SiGe/Si Quantum Wells Under an External Anisotropic Deformation

Resumo

We realize for the first time an experimental investigation of the IR and visible luminescence of SiGe/Si heterostructures with quantum well subjected to an external anisotropic deformation. We show that tensile strain along the [100] direction enhances the absolute and relative intensities of visible luminescence by a factor of 7/3 at a temperature of 5 K. This effect is absent for a tensile strain along the [110] direction. We explain the phenomenon observed in view of the model of single-photon biexciton recombination for the system in which the bottom of the conduction band is formed by only two opposite electronic valleys.