Accession Number : ADA614261


Title :   Synthesis of Few-Layer, Large Area Hexagonal-Boron Nitride by Pulsed Laser Deposition (POSTPRINT)


Descriptive Note : Interim rept. 29 Jan 2013-27 Aug 2014


Corporate Author : AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH FUNCTIONAL MATERIALS DIV


Personal Author(s) : Glavin, Nicholas R ; Jespersen, Michael L ; Check, Michael H ; Hu, Jianjun ; Hilton, Al M ; Fisher, Timothy S ; Voevodin, Andrey A


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a614261.pdf


Report Date : Sep 2014


Pagination or Media Count : 10


Abstract : Pulsed laser deposition (PLD) has been investigated as a technique for synthesis of ultra-thin, few-layer hexagonal boron nitride (h-BN) thin films on crystalline highly ordered pyrolytic graphite (HOPG) and sapphire (0001) substrates. The plasma-based processing technique allows for increased excitations of deposited atoms due to background nitrogen gas collisional ionizations and extended resonance time of the energetic species presence at the condensation surface. These processes permit growth of thin, polycrystalline h-BN at 700 deg C, a much lower temperature than that required by traditional growth methods. Analysis of the as-deposited films reveals epitaxial-like growth on the nearly lattice matched HOPG substrate, resulting in a polycrystalline h-BN film, and amorphous BN (a-BN) on the sapphire substrates, both with thicknesses of 1.5-2 nm. Stoichiometric films with boron-to-nitrogen ratios of unity were achieved by adjusting the background pressure within the deposition chamber and distance between the target and substrate. The reduction in deposition temperature and formation of stoichiometric, large-area h-BN films by PLD provide a process that is easily scaled-up for two-dimensional dielectric material synthesis and also present a possibility to produce very thin and uniform a-BN.


Descriptors :   *BORON NITRIDES , DEPOSITION , MOLECULAR ELECTRONICS , NANOTECHNOLOGY , THIN FILMS , TWO DIMENSIONAL


Subject Categories : Solid State Physics


Distribution Statement : APPROVED FOR PUBLIC RELEASE