Synthesis and Characterization of Novel Self-Generating Liquid MOCVD Precursors for Thin Films of Zinc Oxide

Abstract

Three novel Zn(hfa) 2 ‚2H 2 O‚polyether adducts have been prepared through simple procedures with stoichiometric quantities of zinc hydroxide, Hhfa, and polyether. The products have been characterized by elemental analysis, X-ray single-crystal analysis, fast atom bombardment mass spectra, 1 H and 19 F NMR spectra, thermogravimetric (TG)-differential TG-differential scanning calorimetry (DSC) thermal measurements, and infrared transmittance spectroscopy. An attempt to obtain water-free adduct was unsuccessful even using excess polyethers. X-ray single-crystal data of the Zn(hfa) 2 ‚2H 2 O‚diglyme adduct show that the polyether does not coordinate to the metal center. Nevertheless, metrical data are indicative of bridging interactions involving the oxygen of one coordinated H 2 O molecule and the three oxygens of the diglyme. Very mild heating (37-51 °C) results in liquid compounds that, in turn, can easily be evaporated. Preliminary gas-phase Fourier transform-IR measurements in vacuo suggest that the anhydrous Zn(hfa) 2 ‚diglyme forms upon evaporation due to competing H 2 O and diglyme ancillary ligation. Deposition experiments, in a low-pressure horizontal hot-wall reactor, on fused SiO 2 (quartz) substrates, result in ZnO films. X-ray diffraction measurements provide evidence that they consist of hexagonal ( 002) and (10l) oriented, crystals. UV-vis spectra show that the transmittance of as deposited films in the visible region is about 90%.

Nanostructured CdO thin films for water treatments

“…Synthesis and characterization of the precursor adduct material Cd(C 5 F 6 HO 2 ) 2 Á CH 3 (OCH 2 CH 2 ) 2 OCH 3 (hereafter referred to as Cd(hfa) 2 Á diglyme, mp¼ 45°C) has been reported elsewhere [17][18][19][20]. MOCVD experiments were performed using a horizontal hot-wall reactor under reduced pressure (precursor temperature¼ 90°C, quartz substrate temperature¼400°C, Ar carrier and O 2 reactant gase fluxes ¼100 standard cubic centimeters per minute, total pressure of 4 torr) [17][18][19][20]35].…”

“…Many synthetic procedures have been reported for CdO films [14][15][16]. Recently, we obtained CdO films by a metal organic chemical vapor deposition (MOCVD) route [17][18][19][20], using the Cd (C 5 F 6 HO 2 ) 2 Á CH 3 (OCH 2 CH 2 ) 2 OCH 3 (hereafter referred to as Cd (hfa) 2 Á diglyme) and carried out an extensive structural, electronic and electrical characterization of these films [12].…”

Temperature‐Controlled Synthesis and Photocatalytic Performance of ZnO Nanoplatelets

“…[7,[9][10][11] On this basis, zinc oxide is extensively considered for various applications, from optoelectronics to energetics, sensing, and photocatalysis. [5,6,[12][13][14][15][16][17][18][19][20][21] In particular, the latter field is progressively emerging for its strategic importance in the photoactivated degradation of organic pollutants from industrial wastes. [20,22,23] Despite the most studied photocatalysts by far are those based on TiO 2 , undesired particle aggregation under aging and/or annealing, resulting in a decrease of the photocatalytic efficiency, represents a major drawback.…”

Characterization of amorphous Pt/ZnO films grown on silicon(100) substrates by a photochemical metal organic deposition and their potential use as gas sensors

“…and d.c. magnetron sputtering [15][16][17][18][19][20], chemical vapour deposition [21][22][23], sol-gel methods [24][25][26] and photoassisted CVD [27].…”