Engineering InAs(x)P(1-x)/InP/ZnSe III-V alloyed core/shell quantum dots for the near-infrared
| Autor: | Joseph B. Tracy, John P. Zimmer, Moungi G. Bawendi, Shunsuke Ohnishi, Sang-Wook Kim, John V. Frangioni |
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| Rok vydání: | 2005 |
| Předmět: |
Photoluminescence
Phosphines Analytical chemistry Shell (structure) Quantum yield chemistry.chemical_element Zinc Biochemistry Indium Catalysis Arsenicals Colloid and Surface Chemistry X-Ray Diffraction Quantum Dots Alloys Animals Spectroscopy Selenium Compounds Arsenic Spectroscopy Near-Infrared Sentinel Lymph Node Biopsy General Chemistry Rats chemistry Quantum dot Zinc Compounds X-ray crystallography |
| Zdroj: | Journal of the American Chemical Society. 127(30) |
| ISSN: | 0002-7863 |
| Popis: | Quantum dots with a core/shell/shell structure consisting of an alloyed core of InAs(x)P(1-x), an intermediate shell of InP, and an outer shell of ZnSe were developed. The InAs(x)P(1-x) alloyed core has a graded internal composition with increasing arsenic content from the center to the edge of the dots. This compositional gradient results from two apparent effects: (1) the faster reaction kinetics of the phosphorus precursor compared to the arsenic precursor, and (2) a post-growth arsenic-phosphorus exchange reaction that increases the arsenic content. The cores have a zinc blend structure for all compositions and show tunable emission in the near-infrared (NIR) region. A first shell of InP leads to a red-shift and an increase in quantum yield. The final shell of ZnSe serves to stabilize the dots for applications in aqueous environments, including NIR biomedical fluorescence imaging. These NIR-emitting core/shell/shell InAs(x)P(1-x)/InP/ZnSe were successfully used in a sentinel lymph node mapping experiment. |
| Databáze: | OpenAIRE |
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