Optical properties of CdTe∕ZnTe quantum dots sandwiched between two quantum wells with ZnTe separation barriers

Abstract

Temperature-dependent photoluminescence (PL) measurements were performed to investigate the optical properties of CdTe∕ZnTe nanostructures. The activation energy of the CdTe∕ZnTe quantum dots (QDs) sandwiched between two quantum wells (QWs) with ZnTe separation barriers, as obtained from the temperature-dependent PL spectra, was much larger than the activation energies of the QDs alone and of the QDs combined with a single QW. This behavior can be attributed to a transfer of carriers from the QWs to the QDs through a separation layer due to a nonresonant multiphonon-assisted tunneling process resulting from carrier thermal emission.