Enhancement in Optical Properties of Coupled CdTe/ZnTe Quantum Dots and Quantum Well on Si Substrates

We investigated the optical properties of coupled CdTe quantum dots (QDs) and quantum well (QW) structures with ZnTe separation layers grown on Si substrates. The photoluminescence (PL) intensity of the QDs coupled with a QW increased with decreasing thickness of the ZnTe separation layer. The activation energy of electrons within the coupled structures, which was obtained from temperature-dependent PL spectra, increased with decreasing separation layer thickness. These behaviors were attributed to the tunneling of carriers from the QW to the QDs through a thin separation layer.