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Show HONORS COLLEGE SPRING 2013 BINARY SUPERLATTICES OF SEMICONDUCTOR NANOCRYSTALS: A PATH TOWARDS POSSIBLE HIGH-TEMPERATURE SUPERCONDUCTIVITY Carlos A. Burga (Michael H. Bartl) Department of Chemistry University of Utah This thesis provides a platform to experimentally test Dr. Daniel Mattis'theoretical work on the possible superconductive behavior of nanostructured intrinsic semiconductors. The theoretical work hinged on the nano-scale architecture of semiconductors. Therefore, using various types of semiconductor nanocrystals, i.e., quantum dots, to correspond to Dr. Mattis'single electron models, nanoscale structures were formed by self-assembly methods based on the architecture suggested. In detail, various nanocrystal lattices and binary superlattice combinations were studied. In this work, superlattice combinations of palladium (Pd), gamma iron (III) oxide (y-Fe203), lead selenide (PbSe) and cadmium selenide (CdSe) nanocrystals were studied as possible material platforms. These nanocrystals were chosen based their properties as well as their reported ability to form the desired superlattices.The nanocrystals were synthesized through various metal-organic colloidal nucleation and powder based solution chemistry methods. The superlattice formation, in terms of ordered range and uniformity, was studied by transmission electron microscopy (TEM). Although a few combinations gave moderate results, the best results were obtained with the combination of cadmium selenide and lead selenide in an approximate 12 to 1 molar ratio. The optimization of this superlattice then allows for a sufficiently adequate nanostructure to be formed and will therefore be the starting point for future work on experimental evidence for Dr. Mattis'theory. Transmission Electron Microscope (TEM) image of the binary superlattice produced with cadmium selenide (CdSe) and lead selenide (PbSe) nanocrystals. |
