Synthesis and Characterization of Non-Cadmium Containing Nanocrystals

Semiconductor nanocrystals, or quantum dots, offer unique properties due to their mesoscopic sizes. The best understood system, cadmium selenide, has been rigorously analyzed; however, the toxicity of this material prohibits biological implementation or commercialization. Thus, the characterization of other systems must be developed. The synthesis and characterization of anisotropic lead selenide nanocrystals will be presented; the anisotropy resulting from a rock salt crystal structure will be discussed. It was found that the asymmetric geometries synthesized are a result from the multiple chemical species produced in-situ through the oxidation of the solvent. Additionally, the characterization of dopants inside a nanocrystal matrix will be investigated. Dopants are of interest as they can alter the photophysical and electronic structure of quantum dots. Current methods lack a synthetic methodology that introduces an exact number of dopants per nanocrystal. This can cause inhomogeneity which results in an inability to characterize certain photophysical properties. A novel method that introduces an exact number of copper dopants into a nanocrystal matrix will be presented as well as the unique photophysical and chemical properties that emerge from this homogeneous sample.