Group 13 Metal Doping of Cadmium Selenide Nanocrystals and Atomic Layer Deposition of Copper Oxide and Copper Aluminum Oxide

Abstract

Semiconductors are a broad class of materials and by extension present a large array of possibilities for potential research. This thesis looks at two different areas of semiconductor research. The first is electronic doping of semiconductor nanocrystals and the second is the deposition of copper aluminum oxide via atomic layer deposition (ALD). Semiconductor nanocrystals are semiconductor particles with diameters less than 10 nm. At these size ranges, semiconductor nanocrystals display several unique electrical and optical characteristic due to quantum confinement. Quantum confinement is a phenomenon that arises when the physical size of the nanocrystal is smaller than the wavefunction size of the electrons and holes that allow electrical conductivity in semiconductors. These quantum confinement effects are tunable based on the size of the nanocrystal, which allows one material to have a broad range of possible uses. Even greater control could be had if semiconductor nanocrystals could be doped with heterovalent dopants, as is seen in traditional semiconductors. This thesis look at incorporating group 13 dopants into cadmium selenide nanocrystals and found that while the dopants had effects on the electronic structure of the nanocrystals they were not successfully incorporated into the nanocrystals. The dopants instead were bound to the surface of the nanocrystal. Copper aluminum oxide has generated interest as a potential p-type transparent conductive oxide. Thin films of this material have been deposited via physical vapor methods. Depositing this material via ALD provides a great level of film thickness control, which is critical in many thin film devices. Deposition of copper containing films via ALD has been hampered by a lack of suitable copper precursor. As a solution to that problem, this thesis demonstrates the construction of an ALD deposition system that can use both solid and liquid ALD precursors. This system with its extended capabilities was then used to deposit thin films of copper aluminum oxide using solid copper precursors.