Blue Light Emitting Defective Nanocrystals Composed of Earth‐Abundant Elements
| Autor: | Eric C. Hansen, Yun Liu, Hendrik Utzat, Sophie N. Bertram, Jeffrey C. Grossman, Moungi G. Bawendi |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Photoluminescence
Materials science 010405 organic chemistry Chalcogenide Quantum yield chemistry.chemical_element 02 engineering and technology General Medicine General Chemistry Crystal structure 021001 nanoscience & nanotechnology 010402 general chemistry 01 natural sciences Copper Catalysis 0104 chemical sciences symbols.namesake chemistry.chemical_compound Crystallography chemistry Stokes shift symbols Density functional theory 0210 nano-technology Ternary operation |
| Zdroj: | Angewandte Chemie International Edition. 59:860-867 |
| ISSN: | 1521-3773 1433-7851 |
| DOI: | 10.1002/anie.201911436 |
| Popis: | Copper-based ternary (I-III-VI) chalcogenide nanocrystals (NCs) are compositionally-flexible semiconductors that do not contain lead (Pb) or cadmium (Cd). Cu-In-S NCs are the dominantly studied member of this important materials class and have been reported to contain optically-active defect states. However, there are minimal reports of In-free compositions that exhibit efficient photoluminescence (PL). Here, we report a novel solution-phase synthesis of ≈4 nm defective nanocrystals (DNCs) composed of copper, aluminum, zinc, and sulfur with ≈20 % quantum yield and an attractive PL maximum of 450 nm. Extensive spectroscopic characterization suggests the presence of highly localized electronic states resulting in reasonably fast PL decays (≈1 ns), large vibrational energy spacing, small Stokes shift, and temperature-independent PL linewidth and PL lifetime (between room temperature and ≈5 K). Furthermore, density functional theory (DFT) calculations suggest PL transitions arise from defects within a CuAl5 S8 crystal lattice, which supports the experimental observation of highly-localized states. The results reported here provide a new material with unique optoelectronic characteristics that is an important analog to well-explored Cu-In-S NCs. |
| Databáze: | OpenAIRE |
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