Paper Title
1D And 2D Nickelnanostructures On Highly Ordered Pyrolyticgraphite (HOPG) By Atomic Layer Deposition (ALD)

Abstract
One-dimensional (1D) nanowires (NWs) and two-dimensional (2D) thin films of Ni were deposited on highly ordered pyrolytic graphite (HOPG) by atomic layer deposition (ALD), usingNH3 as a counter reactant. Thermal ALD using NH3 gas forms 1D NWs along step edges, whileNH3 plasma enables the deposition of a continuous 2D film over the whole surface. The lateral and vertical growth rates of the Ni NWs are numerically modeled as a function of the number of ALD cycles. Pretreatment with NH3 gas promotes selectivity in deposition by the reduction of oxygenated functionalities on the HOPG surface. On the other hand, NH3 plasma pretreatment generates surface nitrogen species, and results in a morphological change in the basal plane of graphite, leading to active nucleation across the surface during ALD. The effects of surface nitrogen species on the nucleation of ALD Ni were theoretically studied by density functional theory calculations. In this poster, we introduce the properties of Ni NWs, such as their density and width, and the formation of Ni thin films on carbon surfaces can be controlled by appropriate use of NH3. Keywords: Atomic Layer Deposition, Ni, nanowire, highly ordered pyrolytic graphite (HOPG)