Photoluminescence of colloidal CdSe nano-tetrapods and quantum dots in oxygenic and oxygen-free environments |
| |
Authors: | Lijuan Zhao Qi Pang Shihe Yang Weikun Ge Jiannong Wang |
| |
Affiliation: | (1) School of Physics and CRANN Research Centre, Trinity College, Dublin 2, Ireland;(2) Brest State Technical University, 224017 Brest, Belarus;(3) School of Biochemistry and Immunology, Trinity College, Dublin 2, Ireland;(4) Physikalische Chemie/Elektrochemie, TU Dresden, Bergstr. 66b, 01062 Dresden, Germany;; |
| |
Abstract: | The effects of oxygenic versus oxygen-free environments on colloidal CdSe nano-tetrapods and quantum dots (QDs) were studied using both continuous and time-resolved photoluminescence (PL) measurements. The decays of PL intensities for tetrapods and QDs in oxygen-free solution (chloroform) and in air (on silicon) can be well fitted by a bi-exponential function. Based on the emission-energy dependence of carrier lifetimes and the amplitude ratio of the fast-decay component to the slow-decay component, the fast and slow PL decays of CdSe nanocrystals are attributed to the recombination of delocalized carriers in the core states and localized carriers in the surface states, respectively. The PL intensities of CdSe nano-tetrapods and QDs were found to be five times and an order of magnitude higher in air than in vacuum, respectively, which is explained by the passivation of surface defects by the polar gas (oxygen) absorption. The lower enhancement in PL intensities of CdSe nano-tetrapods is explained by the special morphology of the tetrapods. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|