Synthesis of Type-I CdTe Core and Type-II CdTe/CdS Core/Shell Quantum Dots by a Hydrothermal Method and Their Optical Properties
| Autor: | DaeGwi Kim, Kim Hyeon-Deuk, Kohji Takahashi, Taichi Watanabe, Hang-Beom Bu, Kunio Shimura |
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| Rok vydání: | 2017 |
| Předmět: |
Diffraction
Chemistry Thermal decomposition Analytical chemistry Shell (structure) 02 engineering and technology General Chemistry Electron 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Cadmium telluride photovoltaics Hydrothermal circulation 0104 chemical sciences Crystallography Quantum dot 0210 nano-technology Spectroscopy |
| Zdroj: | Bulletin of the Chemical Society of Japan. 90:52-58 |
| ISSN: | 1348-0634 0009-2673 |
| DOI: | 10.1246/bcsj.20160299 |
| Popis: | CdTe and CdTe/CdS quantum dots (QDs) were synthesized via hydrothermal method in one-step processes just by controlling reaction time. A gradual thermal decomposition of thiol ligand N-acetyl-l-cysteine results in formation of a CdS shell on a CdTe core. The experimental results of X-ray diffraction and energy dispersive X-ray spectroscopy indicated that growth of the CdS shell started in a longer reaction time than 30 minutes and that the thickness of the CdS shell increased with increasing the reaction time. The CdTe/CdS QD exhibited a longer photoluminescence-decay time than the CdTe core QD due to the type-II band alignment, and the decay time in the CdTe/CdS QDs increased with an increase in the reaction time. The increase in the decay time in the CdTe/CdS QDs was qualitatively reproduced by a decrease in an overlap integral of electron and hole wave functions caused by an increase of the CdS shell thickness. |
| Databáze: | OpenAIRE |
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