Synthesis of high aspect ratio quantum-size CdS nanorods and their surface-dependent photoluminescence
Colloidal CdS nanorods with diameters near 4 nm and narrow size distributions ( approximately +/-10%) were synthesized up to 300 nm long by a sequential reactant injection technique that utilizes phosophonic acids as capping ligands. The phosphonic acid strongly passivates the nonpolar CdS surfaces...
| Veröffentlicht in: | Langmuir : the ACS journal of surfaces and colloids. - 1992. - 24(2008), 16 vom: 19. Aug., Seite 9043-9 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2008
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| Zugriff auf das übergeordnete Werk: | Langmuir : the ACS journal of surfaces and colloids |
| Schlagworte: | Journal Article Research Support, N.I.H., Extramural Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. Cadmium Compounds Sulfides cadmium sulfide 057EZR4Z7Q |
| Zusammenfassung: | Colloidal CdS nanorods with diameters near 4 nm and narrow size distributions ( approximately +/-10%) were synthesized up to 300 nm long by a sequential reactant injection technique that utilizes phosophonic acids as capping ligands. The phosphonic acid strongly passivates the nonpolar CdS surfaces and sequential reactant injection provides controlled CdS formation kinetics to enable heterogeneous and facet-selective CdS deposition on the more reactive {002} surfaces. With this process, the nanorod length can be systematically increased by increasing reactant addition to extend nanorod growth. The phosphonic acid concentration, however, is quite important, as "low" concentrations allow radial deposition and branching to occur. These high aspect ratio (>100) CdS nanorods luminesce with relatively high efficiencies of 10.8% quantum yield at room temperature. The luminescence, however, mostly arises from trap-related recombination, and the emission is significantly red-shifted from the absorption edge. Various surface passivation treatments were explored to eliminate trap emission and increase the luminescence quantum yield. Thiol and amine passivation both significantly reduced trap emission and enhanced band-edge emission, but the total luminescence quantum yields dropped significantly, with a maximum measured value of 1.5% for the amine-passivated CdS nanorods |
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| Beschreibung: | Date Completed 17.09.2008 Date Revised 15.11.2012 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1520-5827 |
| DOI: | 10.1021/la800964s |