Temperature Dependence of the Photoluminescence Properties in ZnS-CdS Alloy Quantum Dots Prepared by Using a Colloidal Method

Observations of unusual temperature dependent photoluminescence anti-quenching in two-dimensional nanosheets of ZnS/ZnO composites and polarization dependent photoluminescence enhancement in fungi-like ZnO nanostructures

“…Peculiarities in the PL emission behavior of in-liquid colloidal CdSe/ZnS nanoparticles near the water phase transition temperature (T ¼ 273 K) has been reported by Antipov et al 6 LTAQ effect has also been observed for surface modified CdS QDs and ZnS-CdS alloy QDs and are explained by using a three levels energy model including a triplet origin exciton state, the so called dark exciton state. 7 Anomalous PL emission behavior in isoelectronic ZnSe 1Àx O x semiconductors have been reported very recently and the complex decay profiles induced by O traps had been shown to play the important role. 9 The LTAQ effect observed in porous Si and nanocrystalline ZnO grown on GaInPAs substrates has been explained by using a Berthelot-type behavior of PL emission.…”

“…have also attracted a continued interest due to their oxygen-induced peculiar optical properties. [7][8][9] The incorporation of a small amount of O, having electronegativity much larger than that of S, Se, or Te can dramatically influence the electronic band structure, such as band gap bowing and hence the absorption and photoluminescence (PL) emission characteristics can be tuned over the entire UV-visible range, by tuning the oxygen content in the samples. 8,9 Though a lot of experimental and theoretical studies have been carried out on Mg x Zn 1Àx O, Cd x Zn 1Àx O, and Be x Zn 1Àx O semiconductors but relatively less attention has been paid on ZnS 1Àx O x due to the large difference in the electronegativity between O and S resulting in a larger bowing parameter.…”