Using CdSe/CdS core/shell nanocrystals with 1-10 monolayers of CdS shell as the model system, we studied effects of thiol ligands on optical properties of the nanocrystals. The core/shell nanocrystals with original li...Using CdSe/CdS core/shell nanocrystals with 1-10 monolayers of CdS shell as the model system, we studied effects of thiol ligands on optical properties of the nanocrystals. The core/shell nanocrystals with original ligands possessed near unity photoluminescence （PL） quantum yield and single-exponential PL decay dynamics. The effects of thiol ligands on optical properties were found to depend on the shell thickness, environment （with/without oxygen）, and excitation power （single- or multi-exciton）. Systematic and quantitative results reported in this work should provide necessary information for fundamental understanding and technical applications of quantum dots （QDs） coated with thiol ligands.展开更多
In this paper, we demonstrate that for colloidal CdSe/CdS nanoplatelets, a rectangular shape induces emission asymmetry, in terms of both polarization and emission patterns. Polarimetry and emission pattern analyses a...In this paper, we demonstrate that for colloidal CdSe/CdS nanoplatelets, a rectangular shape induces emission asymmetry, in terms of both polarization and emission patterns. Polarimetry and emission pattern analyses are combined to provide information on the orientation of the transition dipoles involved in the nanoplatelet emission. It is shown that for rectangular nanoplatelets, the emission is polarized and the emission patterns are anisotropic, whereas they remain nonpolarized and isotropic for square nanoplatelets. This can be appropriately described by the dielectric antenna effect induced by the elongated shape of the rectangular platelet.展开更多
基金This work was supported in part by the National Natural Science Foundation of China （NSFC） （Nos. 21233005 and 91433204） and Fundamental Research Funds for the Central Universities （No. 2014FZA3006）.
文摘Using CdSe/CdS core/shell nanocrystals with 1-10 monolayers of CdS shell as the model system, we studied effects of thiol ligands on optical properties of the nanocrystals. The core/shell nanocrystals with original ligands possessed near unity photoluminescence （PL） quantum yield and single-exponential PL decay dynamics. The effects of thiol ligands on optical properties were found to depend on the shell thickness, environment （with/without oxygen）, and excitation power （single- or multi-exciton）. Systematic and quantitative results reported in this work should provide necessary information for fundamental understanding and technical applications of quantum dots （QDs） coated with thiol ligands.
文摘In this paper, we demonstrate that for colloidal CdSe/CdS nanoplatelets, a rectangular shape induces emission asymmetry, in terms of both polarization and emission patterns. Polarimetry and emission pattern analyses are combined to provide information on the orientation of the transition dipoles involved in the nanoplatelet emission. It is shown that for rectangular nanoplatelets, the emission is polarized and the emission patterns are anisotropic, whereas they remain nonpolarized and isotropic for square nanoplatelets. This can be appropriately described by the dielectric antenna effect induced by the elongated shape of the rectangular platelet.
