Typical HREM plan-view images of Cd0.5Zn0.5 S QDs (a) embedded in the organic matrix, (b) annealed at 200 °C and (c) annealed at 350 °C. HREM images of Cd0.8Zn0.2 S QDs (d) and (e) annealed at 200 °C and (f) annealed at 350 °C.
(Color online) Histograms of the QD size distribution for samples Cd1−xZnx S QDs with a nominal Zn content (a) x = 0.3, (b) x = 0.5, (c) and x = 0.8 embedded in an organic matrix; (d) x = 0.3, (e) x = 0.5, and (f) x = 0.8 annealed at 200 °C; and (g) x = 0.5 (h) and x = 0.2 annealed at 350 °C. The distribution of the QD size dispersion is fitted with Gaussian curves, from which we obtain the average QD size and the size distribution.
(Color online) (a) STEM HAADF image, chemical maps of (b) Zn, (c) Cd and (d) S, and (e) the integrated EDX drift-corrected spectrum of Cd0.2Zn0.8 S QDs annealed at 200 °C.
(Color online) UV–vis absorption spectra of CdZnS QDs with different nominal compositions (a) embedded in an organic matrix, (b), annealed at 200 °C, and (c) annealed at 350 °C.
(Color online) Raman spectra of CdZnS QDs (a) annealed at 200 °C and (b) annealed at 350 °C, measured with a 325 nm excitation source.
(Color online) Dependence of the experimentally determined CdZnS QD composition as a function of the nominal Zn content. Open and solid symbols are the data obtained from UV–vis absorption and Raman experiments, respectively. Circles, squares, and triangles correspond to CdZnS QDs embedded in the matrix, annealed at 200 °C, and annealed at 350 °C, respectively. Dashed lines present results based on calculations within the LS theory.
Article metrics loading...
Full text loading...