INIFTA   05425
INSTITUTO DE INVESTIGACIONES FISICO-QUIMICAS TEORICAS Y APLICADAS
Unidad Ejecutora - UE
artículos
Título:
Inorganically coated colloidal quantum dots in polar solvents by microemulsion-assisted SILAR
Autor/es:
MIZRAHI, MARTIN; GRANADOS, DANIEL; HERRERA, FACUNDO C.; BERNARDO-GAVITO, RAMON; JUAREZ, BEATRIZ; ACEBRON, MARIA; NAVIO, CRISTINA; REQUEJO, FELIX G.
Revista:
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
Editorial:
ROYAL SOC CHEMISTRY
Referencias:
Lugar: CAMBRIDGE; Año: 2016 vol. 19 p. 1999 - 2007
ISSN:
1463-9076
Resumen:
The role of long, amphiphilic organic ligands is essential for the synthesis of semiconductor nanocrystals (NCs) pro-duced by hot injection. Nevertheless, their dielectric nature makes them incompatible with optoelectronic or bio-applications. For these reason, the ligands must be substituted by shorter or even atomic ones, with higher conductivi-ty or bio-compatibility. In this work, the successive ionic layer adsorption reaction (SILAR) is applied to control the growth of S and Zn layers in microemulsions on CdSe seeds previously produced by hot injection. Mild reactants with different reactivity widely employed in chemical bath deposition approaches have been explored. The procedure involves the partial removal of the original phosphonate ligand shell, yielding connected QDs, resembling 1D worm-like structures. The obtained NCs are composed of several species, including sulfides and more oxidized ones, as confirmed by X-ray Absorption Near Edge Structure (XANES), Extended X-ray Absorption Fine Structure (EXAFS) and X-ray Photoelectron Spectroscopy (XPS). The developed procedure improves the optical properties of the initial CdSe seeds according to type-I or quasi type-II structures, reduces their solubility in non-polar media (toluene, chloroform) and increases the sample stability in polar media such as isopropanol, ethanol, and formamide. The 1D morphology along with the lack of long insulating ligands and the higher solubility in polar media could be very useful for their integration into optoelectronic devices.