• Transactions on Electrical and Electronic Materials
• /
• v.18 no.3
• /
• pp.155-158
• /
• 2017

In this paper, ZnO Thin Film Transistors (TFTs) were fabricated by a sol-gel method using a low-temperature process, and their physical and electrical characteristics were analyzed. To lower the process temperature to $200^{\circ}C$, we used a zinc nitrate hydrate ($Zn(NO_3)_2{\cdot}xH_2O$) precursor. Thermo Gravimetric Analyzer (TGA) analysis showed that the zinc nitrate hydrate precursor solution had 1.5% residual organics, much less than the 6.5% of zinc acetate dihydrate at $200^{\circ}C$. In the sol-gel method, organic materials in the precursor disrupt formation of a high-quality film, and high-temperature annealing is needed to remove the organic residuals, which implies that, by using zinc nitrate hydrate, ZnO devices can be fabricated at a much lower temperature. Using an X-Ray Diffractometer (XRD) and an X-ray Photoelectron Spectrometer (XPS), $200^{\circ}C$ annealed ZnO film with zinc nitrate hydrate (ZnO (N)) was found to have an amorphous phase and much more oxygen vacancy ($V_o$) than Zn-O bonds. Despite no crystallinity, the ZnO (N) had conductance comparable to that of ZnO with zinc acetate dihydrate (ZnO (A)) annealed at $500^{\circ}C$ as in TFTs. These results show that sol-gel could be made a potent process for low-cost and flexible device applications by optimizing the precursors.

• Journal of the Korean Ceramic Society
• /
• v.42 no.4
• /
• pp.245-250
• /
• 2005

ZnO was deposited on sapphire single crystal substrate by an ultrasonic pyrolysis of Zinc Acetate Dehydrate (ZAH) with carrying Ar gas. Through Thermogravimetry-Differential Scanning Calorimetry(TG-DSC), zinc acetate dihydrate was identified to be dissolved into ZnO above $380^{\circ}C$. ZnO deposited at $380-700^{\circ}C$ showed polycrystalline structures with ZnO (101) and ZnO (002) diffraction peaks like bulk ZnO in XRD, and from which c-axis strain ${\Sigma}Z=0.2\%$ and compressive biaxial stress$\sigma=-0.907\;GPa$ was obtained for the ZnO deposited $400^{\circ}C$. Scanning electron microscope revealed that microstructures of the ZnO were dependent on the deposition temperature. ZnO grown below temperature $600^{\circ}C$ were aggregate consisting of zinc acetate and ZnO particles shaped with nanoblades. On the other hand the grain of the ZnO deposited at $700^{\circ}C$ showed a distorted hexagonal shape and was composed of many ultrafine ZnO powers of 10-25 nm in size. The formation of these ulrafine nm scale ZnO powers was explained by the model of random nucleation mechanism. The optical property of the ZnO was analyzed by the photoluminescence (PL) measurement.

• Advances in nano research
• /
• v.2 no.4
• /
• pp.179-186
• /
• 2014

Indium-nitrogen co-doped zinc oxide thin films (INZO) were prepared on glass substrates in the atmosphere by ultrasonic spray pyrolysis. The aqueous solution of zinc acetate, ammonium acetate and different indium sources: indium (III) chloride and indium (III) nitrate were used as the precursors. After film deposition, different anneal temperature treatment as 350, 450, $550^{\circ}C$ were applied. Electrical properties as concentration and mobility were characterized by Hall measurement. The surface morphology and crystalline quality were characterized by SEM and XRD. With the activation energy analysis for both films, the concentration variation of the films at different heat treatment temperature was realized. Donors correspond to zinc related states dominate the conduction mechanism for these INZO films after $550^{\circ}C$ high temperature heat treatment process.

• Transactions of the Korean hydrogen and new energy society
• /
• v.33 no.1
• /
• pp.113-120
• /
• 2022

Quantum dots (QDs) are attractive photosensitizer candidates for application not only in solar cells but also in solar hydrogen generation. For the prepartion of highly efficient QD-sensitized photoelectrodes, it is important to reduce electron recombination at the photoanode/electrolyte interface. Here, we study on the coating condition of ZnS passivation layers on the photoanodes in QD-sensitized solar cells (QDSCs). The ZnS passivation layers are coated by successive ionic layer adsorption and reaction method, and as the cation precursor, zinc acetate and zinc nitrate are empolyed. Due to the higher pH of cation precursor solution, the ZnS loading is improved when the zinc acetate is used, compared to the zinc nitrate. This improved loading of ZnS leads to the reduced electron recombination at the surface of photoanodes and the enhaced conversion efficiency of QDSCs from 6.07% to 7.45%.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.35 no.1
• /
• pp.35-41
• /
• 2006

Antibacterial activities of the trace elements in combination with the food additives were measured against 6 kinds of food-borne microorganisms such as Escherichia coli, Vibrio parahaemolyticus, Staphylococcus aureus, Bacillus cereus, Bacillus subtilis and Pseudomonas fluorescens. The difference of antibacterial activity was not shown among the kinds of food additives, such as dextrin, gelatin and collagen. Zn and Ge in combination with food additives had strong antibacterial effect. Especially, $1\%$ zinc acetate in combination with $1\%$ gelatin was more effective against P. fluorescens and S. aureus than against Bacillus sp., E. coli and V. parahaemolyticus. Minimum inhibitory concentration of zinc acetate in combination with $1\%$ gelatin appeared to be 0.5 mg/mL on S. aureus and P. fluorescens, and 1.0 mg/mL on E. coli, V. parahaemolyticus, B. cereus and B. subtilis. Minimum bactericidal concentration of zinc acetate in combination with $1\%$ gelatin appeared to be 0.5 mg/mL on P. fluorescens and 1.0 mg/mL on E. coli, V. parahaemolyticus, S. aureus, B. cereus and B. subtilis. The zinc acetate in combination with gelatin showed stronger inhibitory effect in acidic range below pH 6.0, and remained active even after heat treatment at $121^{\circ}C$ for 15 min. In comparison with control, the viable cell counts of fish pastes, which were coated with the solution containing both $1\%$ zinc acetate and $3\%$ gelatin, were decreased by more than 100-fold until the storage of 7 days at $10^{\circ}C$. The results indicate that the combined use of zinc acetate and some food additives could prolong the shelf life of fish pastes by 8 days or more at $10^{\circ}C$.

• Bulletin of the Korean Chemical Society
• /
• v.18 no.4
• /
• pp.441-442
• /
• 1997

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.21 no.5
• /
• pp.205-209
• /
• 2011

Zinc oxide has semi-conductivity and super conductivity characteristics. It can be used optically and is applied on many areas such as gas sensor, solar cell and optical waveguide. In this paper, to improve optical characteristics of ZnO, aluminum was added on zinc oxide. Zinc oxide and aluminum zinc oxide was fabricated as nano fiber form. ZnO solution was created by mixing poly vinyl pyrrolidone, ethyl alcohol, and zinc acetate. An Al doped ZnO was created by adding aluminum solution to ZnO sol. By applying these sols on electro spinning method, nano fibers were fabricated. These fibers are heat treated at 300, 500, and $700^{\circ}C$ degrees and were analyzed with X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) to examine the nano structures. TGA and DSC measurement was also used to measure the change of mass and calorie upon temperature change. The absorbance of ZnO and Al-doped ZnO was carried out by UV-vis measurement.

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2003.11a
• /
• pp.191-195
• /
• 2003

Zinc acetate has been proposed and used to evaluate ionic zinc as a means to reduce reactor radiation buildup at several nuclear plants. Thermodynamic analysis of the aqueous zinc system using reliable data shows that the stability of the hydrolyzed zinc species increases with pH and temperature. Adsorption kinetics and isotherm studies were carried out to investigate the mixed resin performance of the zinc adsorption. The equilibrium isotherms of the zinc adsorption onto nuclear grade resin indicate that the data correlate well with the Langmuir model and that the adsorption is physical in nature. The maximum capacity according to the Langrnuir model is about 0.6meq/g for an initial zinc concentration of 100ppm at $50^{\circ}C$. The use of natural zinc could result in the generation of a $^{65}Zn$ activity with about $500{\mu}Ci/mL$ of resin after 12 months of operation.

• Food Science and Preservation
• /
• v.31 no.1
• /
• pp.126-137
• /
• 2024

In this study, zinc oxide nanoparticles (ZnONPs) were synthesized using three distinct zinc salts: zinc acetate, zinc chloride, and zinc nitrate. These ZnONPs were subsequently utilized in the fabrication of carrageenan-ZnONPs (Car-ZnONPs) composite films. The study assessed influence of the various ZnONPs on the morphological, water vapor barrier, color, optical, and antimicrobial properties of the Car-ZnONPs composite films. The surface morphology and UV-blocking attributes of the composite films were affected by the type of ZnONPs used, but their surface color, transparency, and chemical structure remained unaltered. The composite film's thickness and elongation at break (EB) significantly increased, while the tensile strength significantly decreased. In contrast, film's elastic modulus (EM) and water vapor permeability coefficient (WVP) showed no significant difference. All the composite films with added ZnONPs demonstrated potent antibacterial activity against Escherichia coli O157:H7 and Listeria monocytogenes . Among the carrageenan-based composite films, Car-ZnONPs^ZC showed the highest antibacterial and UV-blocking properties, and its elongation at break was significantly higher than that of the pure carrageenan films. This suggests that ZnONPs composite films have the potential to be used as an active packaging film, preserve the safety of the packaged food and extend shelf life.

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2006.09a
• /
• pp.676-677
• /
• 2006

Synthesis of zinc oxide nanorods, sheets and flower like structure were done by the sol-gel method using zinc acetate dihydrate and sodium hydroxide at $80^{\circ}C$ with 12 hours refluxing time nanorods, in case of as synthesized powder, with diameter of 20-60nm. Annealing at higher temperature (300 and $500^{\circ}C$,) in air ambient changes the morphology to sheet and flower like structure. The standard peak of zinc oxide was observed in IR at $523cm^{-1}$. The UV-VIS spectroscopy of zinc oxide shows a characteristic peak at 375nm.