Molecular mechanism of monodisperse colloidal tin-doped indium oxide nanocrystals by a hot-injection approach
1 State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou, 310027, People's Republic of China
2 Cyrus Tang Center for Sensor Materials and Applications, Zhejiang University Hangzhou, Zhejiang, 310027, People's Republic of China
3 College of Chemistry & Materials Engineering, Wenzhou University, Wenzhou, Zhejiang Province, 325027, People's Republic of China
Nanoscale Research Letters 2013, 8:153 doi:10.1186/1556-276X-8-153Published: 2 April 2013
Molecular mechanisms and precursor conversion pathways associated with the reactions that generate colloidal nanocrystals are crucial for the development of rational synthetic protocols. In this study, Fourier transform infrared spectroscopy technique was employed to explore the molecular mechanism associated with the formation of tin-doped indium oxide (ITO) nanocrystals. We found that the reaction pathways of the indium precursor were not consistent with simple ligand replacements proposed in the literature. The resulting understanding inspired us to design a hot-injection approach to separate the ligand replacements of indium acetate and the aminolysis processes, generating quality ITO nanocrystals with decent size distributions. The hot-injection approach was readily applied to the synthesis of ITO nanocrystals with a broad range of tin doping. Structural, chemical, and optical analyses revealed effective doping of Sn4+ ions into the host lattices, leading to characteristic and tunable near-infrared surface plasmon resonance peaks. The size control of ITO nanocrystals by multiple hot-injections of metal precursors was also demonstrated.