Single-Step Synthesis of Quantum Dots with Chemical Composition Gradients
- Bae, Wan Ki
- Char, Kookheon
- Hur, Hyuck
- Lee, Seonghoon
DOIAbstract
We demonstrate a single-step synthetic method for highly luminescent (i.e., quantum yield up to 80%) and stable quantum dots (QDs) by using the reactivity difference between Cd and Zn precursors and that between Se and S precursors. A wide range of emission wavelengths (500−610 nm) with a narrow fwhm (<35 nm) is obtained by changing the ratios of the precursors. Under the reaction conditions selected, Cd- and Se (with a bit of S)-based cores are formed first and Zn- and S-based shells are formed successively; therefore, the QDs have a core/shell structure with composition gradients, which relieve the lattice mismatch between core and shells. The QDs are characterized using the combined techniques of HR-TEM, UV–vis, PL spectroscopy, and ICP-...
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