Vanadyl triethoxide (or vanadium triethoxide oxide) (VO(OEt)3) was applied as metal-organic vanadium precursor for the MOCVD growth of epitaxial VO2 films (and multilayered VO2/TiO2 stacks – using Ti(OiPr)4 as co-precursor) on sapphire (a-Al203)
single-crystal substrates ((11-20), (0001) and (1-102)); O2 was used as oxidant, high purity N2 as carrier gas. The growth conditions were following: growth temperatures 400-800°C, growth pressure 5-20 Torr, total gas glow 1300sccm, O2 flow rate 200sccm,
MO source temperature 40-65°C, MO flow rate 10-100sccm, the obtained growth rates 0.3-15 nm/min, layer thickness 30-300 nm. Layer structure depended strongly on the substrate material, surface orientation and the growth temperature, but was insensitive
to other growth parameters. The observed 7 distinct epitaxial orientation layer/substrate relationships were explained based on material atomic arrangements. It was determined that single layer films (both VO2 and TiO2) were formed by the nucleation of three-dimensional
clusters. Electronic structures, charge distributions, and energetics of the free substrate surfaces of VO2 layers were investigated by quantum mechanical calculations.[i]
[i] H.L.M. Chang, Y. Gao, J. Guo, C.M. Foster, H. You, T.J. Zhang, D.J. Lam, J. Phys. IV CZ-95 3, Coll.C2, suppl. au J. Phys. 11, 1991, Vol 1 , « Heteroepitaxial growth of TiO2, VO2, and TiO2/VO2 multilayers by MOCVD », https://hal.archives-ouvertes.fr/file/index/docid/249794/filename/ajp-jp4199102C2115.pdf, https://jp4.journaldephysique.org/articles/jp4/abs/1991/02/jp4199102C2115/jp4199102C2115.html
Triethoxylvanadyl VO(OEt)3 has been applied for the growth of V5+-doped
semi-insulating GaAs layers by MOCVD. At room temperature the resistivity of the grown GaAs:V layers was ≥108 Ω·cm. Wide range of growth conditions was
suitable for the growth of semi-insulating layers, which were quite stable to high temperature treatment. Over 1018 cm-3 level concentration was achieved without surface
roughening. VO(OEt)3 as dopant did not present any memory effects. [i]
[i] M. Akiyama, Y. Kawarada, K. Kaminishi, J. Cryst. Growth, 1984, Vol. 68, Iss. 1, p.39-43, « Growth of vanadium-doped semi-insulating GaAs by MOCVD », https://doi.org/10.1016/0022-0248(84)90394-4, https://www.sciencedirect.com/science/article/pii/0022024884903944
Triisopropoxyvanadyl VO(OiPr)3 has been applied as V precursor for the MOCVD growth of V-doped TiO2 thin films (V doping level up to 40 at%) on sapphire (0001), (112̄0),
and (011̄2) substrates. V-doped TiO2 films exhibited phase separation. V5+ oxidation state was revealed in the V-doped TiO2 films by XPS. V-doped TiO2 films are consisting of epitaxial TiO2 rutile islands in a V2O5 matrix, according to XRD and AFM.[i]
[i] Y. Gao, S. Thevuthasan, D.E. McCready, M. Engelhard, J. Cryst. Growth, 2000, Vol. 212, Iss. 1–2, p.178-190 MOCVD growth and structure of Nb- and V-doped TiO2 on sapphire, https://doi.org/10.1016/S0022-0248(00)00010-5, https://www.sciencedirect.com/science/article/pii/S0022024800000105