Fatty acid makes nanocrystals
doi:10.1038/nindia.2010.67 Published online 26 May 2010
Fatty acid found in various animals and vegetables aid in the synthesis of nano-sized crystals that help make quantum dots.
Quantum dots (semiconductor with diameter of 10-50 atoms) are of great interest for their applications in different fields like light emitting diodes, solar cells, bioimaging and display devices.
Cadmium sulphide (CdS) is essential to make quantum dots. This led the researchers to devise a method to synthesise CdS nanocrystals using free fatty acid (oleic acid). They used elemental sulphur and Cd-carboxylate precursors in organic solvent at reduced temperature.
The amount of free acid not only changed the growth but also controlled the growth rate of CdS nanocrystals. Sulfur reacts with free acid and releases hydrogen sulphide gas. Sulphide ions in the reaction system enhance the growth rate of CdS nanocrystals.
"It is a low temperature synthesis method and high quality CdS nanocrystals can be synthesised in any laboratory following this technique," says lead researcher Narayan Pradhan from the Department of Materials Science and Centre for Advanced Materials, Indian Association for the Cultivation of Science, Kolkata.
- Karan, S. N. et al. Role of Fatty Acid in Controlling Nucleation and Growth of CdS Nanocrystals in Solution. J. Phys. Chem. C. 114, 8873-8876 (2010) | Article |