Assembly of CdSe/ZnS nanocrystals on microwires and nanowires for temperature sensing

Methods for assembling semiconductor nanocrystals on top of micro- and nanowires are presented. One method utilizes a simple drying process while the other is based on electrical field forces. Electrical field assembly is achieved by the creation of a non-uniform ac electrical field between a micro- or nanowire and a flat macroelectrode. The choice of assembly method depends mainly on the surface properties of the wire sample. As for electrical field assembly, it is found that a slightly different setup has to be used for successful assembly on nanowires as compared to the microwire case. By taking advantage of the temperature dependent fluorescence of semiconductor nanocrystals, these assembly techniques will be useful in mapping the temperature on electrically heated nanowires. Once these characteristics are known, nanowires may potentially be employed as nanoheaters in order to control, with high spatial and temporal precision, the temperature in single molecule studies.