Colloidal semiconductor nanocrystals have shown great promise in functional devices
such as solar cells and LEDs, but still relatively little is understood about the chemistry of their formation and resulting structure. In this thesis, we describe the results of our study of ultrathin Bi2S3 nanowires, part of the emerging class of materials at the transition from molecular scale clusters to nanowires, from a chemical perspective. Using a complementary suite of techniques, we propose an atomically precise model of the nanowires accounting for both the inorganic core structure and ligand-surface interaction for purified dispersions. The growth process of the nanowires was studied using in situ NMR on reaction mixtures and information on the growth and reactivity not attainable with purified dispersions was gained. The small molecule reactivity of the sulfur-oleylamine precursor was elucidated and it was shown that H2S is produced in situ leading to the formation of Bi2S3. This knowledge allowed for the extension of the sulfur-oleylamine precursor to SemSn-oleylamine, which produces H2S and H2Se in situ leading to the formation of homogeneous solid-solution PbSxSe1-x nanocrystals with tunable stoichiometry. Through this work, we elucidated each stage of the nanowire
formation from small molecule reactivity, to growth process, to solution phase structure.
| Identifer | oai:union.ndltd.org:TORONTO/oai:tspace.library.utoronto.ca:1807/32828 |
| Date | 31 August 2012 |
| Creators | Thomson, Jordan |
| Contributors | Ozin, Geoffrey Alan |
| Source Sets | University of Toronto |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
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