B(OMe)3 for BN nanotubes by MOCVD
Trimethylborate B(OMe)3 (together with N2 as N-source) has been applied for the growth of crystalline boron nanotubes by thermal CVD at temperature 1000-1200°C.
Ttrimethyl borate was evaporated at 60 °C , nitrogen gas flew into reaction chamber. 434 stainless steel wires were used as substrates.
The the overall reaction to produce BN crystals was as follows:
C3H9BO3(g) +N2(g)→ BN(s) +NH3(g) +3CO(g)
The residual gases of NH3(g) + 3CO(g) were removed from the reaction system through a water tank by a rotary pump. BN crystals formed on the coil surface and catalyzed by the Fe, Cr, Mo elements provided from the surface of the coil scaffold [[i]]
[i] Feng-Huei Lin, , Chung-King Hsu, Tzu-Piao Tang, Pei-Leun Kang and Fan-Fung Yang, Materials Chemistry and Physics, Volume 107, Issue 1, 15 January 2008, Pages 115-121 “Thermal-heating CVD synthesis of BN nanotubes from trimethyl borate and nitrogen gas”
Triisopropylborate B(OiPr)3
B(OiPr)3 for BaB2O4 by liquid injection MOCVD
Triisopropylborate B(OiPr)3 has been applied as boron source for the growth of β-BaB2O4 thin films on Si(100) substrates by injection MOCVD (in combination with Ba(thd)2 as Ba source; both precursors were dissolved in triglyme solvent: B(OiPr)3concentration was 2×10−2 mol/l; solution composition (B:Ba molar ratio)=2:1). Other growth conditions were following: evaporator temperature 250 °C, Ar carrier flow 190 sccm, O2 flow 10 sccm, total pressure 133 Pa (1 Torr), injector opening time 1 ms/ injection frequency 1 Hz. The films were characterized by optical microscopy, micro-Raman spectroscopy (showing intense peak at 637 cm− 1 as fingerprint of β-BBO), and XPS (measurement of the Ba, B and O core levels reported for the first time for β-BBO thin films). [[i]]
In another study, the organic solution containing triisopropyl borate B(OiPr)3 and Ba(thd)2•tetraglyme, was transported (with 200sccm N2) to the MOCVD reactor at 7 mmol/h by liquid delivery system ATMI, flash vaporized in the vaporizer, and thermally decomposed at the substrate resulting in the deposition of thin β-BaB2O4 films by metalorganic chemical vapor deposition on fused silica, sapphire, platinum, and silicon substrates (with c-axis oriented perpendicular to the substrate).The highest quality films grown on sapphire weregrownat720 °Cwithaslightexcessof boronintheprecursorsolution. Second harmonic generation measurements have been made on selected films; the films grown on single-crystal sapphire exhibit a maximum χeff(2) 1.6 pm/V and on fused silica 0.78 pm/V. [[ii]]
[i] S. Wersand-Quell, G. Orsal, P. Thévenin, A. Bath, Thin Solid Films, Volume 515, Issue 16, 4 June 2007, Pages 6507–6511, “Growth of beta barium borate (β-BaB2O4) thin films by injection metal organic chemical vapour deposition”, http://www.sciencedirect.com/science/article/pii/S004060900601460X
[ii]Studebaker, D.B., Stauf, G.T. ; Baum, T.H. ; Marks, T.J. ; Zhou, H. ; Wong, G.K., Applied Physics Letters (Volume:70 , Issue: 5 ), Feb 1997, Page(s): 565 - 567 “Second harmonic generation from beta barium borate (β-BaB2O4) thin films grown by metalorganic chemical vapor deposition”