Stoichiometric controlling of pulsed laser deposited boron-carbon thin films

The stoichiometry of B-C thin films was controlled via pulsed laser deposition using a series of ceramic B-C targets (B/C ratio was 3.04-5.92). The effects of B/C ratio in target, laser power and substrate-to-target distance on deposition rate, microstructure, stoichiometry and chemical structure were investigated. The maximum deposition rate was obtained at laser power of 90 mJ and substrate-to-target distance of 50 mm. Boron rich B-C films were obtained and the stoichiometry in B-C thin films was controlled in the range 2.9-4.6. Carbon atoms were bonded with only sp(3) hybridization when boron was rich,but with sp(2) and sp(3) hybridizations when carbon was rich. Crown Copyright (C) 2012 Published by Elsevier B.V. All rights reserved.