Self-Assembly of TGA-Capped CdTe Nanocrystals into Three-Dimensional Luminescent Nanostructures

In this paper, we report on a convenient and quick self-assembly of thioglycolic acid (TGA)-capped CdTe nanocrystals (NCs) into three-dimensional (3D) nanostructures in solution, in which large-scale nanowires are found as building blocks. The wet 3D nanostructures can be further dried by critical CO(2) to obtain solids with a volume of about 1 cm(3) and a density of about 1/2500th of bulk CdTe. By SEM, EDS, and HRTEM characterization, it is found that the nanowires actually are CdTe@Cd-TGA complex hybrid nanostructures in which many well-separated CdTe NCs are uniformly distributed. The hybrid nanowires can reach several micrometers in length and 25 +/- 8 nm in width. As a result of the CdTe NCs with their integrity and effective protection by the Cd-TGA complex, the hybrid nanowires and 3D nanostructures still show visually bright luminescence and retain the size-quantized properties of the CdTe NCs. This new kind of QD-based nanostructures may be suitable for subsequent processing into quantum-confined superstructures, materials and devices.