Fluorescence quantum yield of CdSe/ZnS nanocrystals investigated by correlated a

2019-12-13 00:07:53

single particle quantum fluorescence microscopy

责任者: Ebenstein, Y.;Mokari, T.;Banin, U. 单位: Center for Nanosci. & Nanotechnol., Hebrew Univ., Jerusalem, Israel 来源出处: Applied Physics Letters(Appl. Phys. Lett. (USA)),2002/05/27,80(21):4033-5 摘要: Correlated atomic-force and fluorescence microscopy are used to study single-particle versus ensemble fluorescence quantum yields (QY) of semiconductor nanocrystals by measuring a simultaneous map of the topography and the single-particle fluorescence. CdSe/ZnS nanocrystal quantum dots and quantum rods with high QY were investigated. A significant portion of dark particles is detected. Comparison with the ensemble solution QY shows that samples with higher QY have a larger fraction of bright particles accompanied by an increased single-particle QY. Saturated emission from single nanocrystals could not be detected because of particle darkening under high-power excitation 关键词: atomic force microscopy;cadmium compounds;fluorescence;II-VI semiconductors;nanostructured materials;optical microscopy;semiconductor quantum dots;surface topography;zinc compounds;fluorescence quantum yield;atomic-force microscopy;single-particle fluorescence microscopy;semiconductor nanocrystals;topography;quantum dots;quantum rods;dark particles;bright particles;high-power excitation;CdSe-ZnS