Tungsten oxo tetrakis(2,2,2-trifluoroethoxide) W(O)(OCH2CF3)4 was synthesized from W(O)Cl4 and CF3CH2OH in the presence of NH3. The synthesized complex was shown to be monomeric.
W(O)(OCH2CF3)4 was applied as a precursor for the deposition of tungsten oxide thin films by AACVD. When W(O)(OCH2CF3)4 was used as a single‐source precursor (without co-reagent), non-stoichiometric WO2.9 layers were obtained; whereas when O2 as co‐reagent was added, stoichiometric WO3 layers were obtained. [i]
[i] K. C. Molloy, P. A. Williams, Appl. Organomet. Chem., 2008, Vol.22, Iss.10, p.560-564, https://doi.org/10.1002/aoc.1439, « Atmospheric pressure chemical vapour deposition of WO3 thin films from a volatile fluorinated tungsten oxo‐alkoxide precursor, W(O)(OCH2CF3)4 »
Tungsten(VI) oxo fluoroalkoxides WO[OCMe(CF3)2]4 and WO[OCMe2CF3]4 were applied as single-source precursors for the AACVD deposition of substoichiometric amorphous tungsten oxide WOx thin films on indium tin oxide (ITO) substrates in N2 at low deposition temperature (100–250 °C). W18O49 monoclinic crystalline phase was obtained at growth temperatures >300 °C. The grown WOx layers were characterized by investigated in terms of their surface morphology/ roughness, visible light transmittance, electrical conductivity, work function. Surface morphology and composition were minimally affected by the solvent and carrier gas at low deposition temperatures; however, at higher temperatures material crystallinity was dependent on the solvent choice. according to ultraviolet photoelectron spectroscopy (UPS), the work function of the WOx thin films deposited at 150- 250 °C was in the range 5.0-5.7 eV.[[i]]
[i] H. Kim, R.O. Bonsu, Ch. O’Donohue, R.Y. Korotkov, L. McElwee-White, T.J. Anderson, ACS Appl. Mater. Interfaces 2015, 7, 4, 2660–2667, « Aerosol-Assisted Chemical Vapor Deposition of Tungsten Oxide Films and Nanorods from Oxo Tungsten(VI) Fluoroalkoxide Precursors », https://doi.org/10.1021/am507706e, https://pubs.acs.org/doi/abs/10.1021/am507706e