• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.5
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• pp.347-350
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• 2013

By inserting a very thin metal layer of Ag between two outer oxide layers of amorphous silicon indium zinc oxide (SIZO), we fabricated a highly transparent SIZO/Ag/SIZO multilayer on a glass substrate. In order to find the optimized thickness of Ag layers, we investigated the variation of optical properties depending on Ag thickness. It was found that the transition of Ag layer from island formation to a continuous film occurred at a critical thickness. Continuity of the Ag film is very important for optical properties in SIZO/Ag/SIZO multilayer. With about 15 nm thick Ag layer, the multilayer showed a high optical transmittance of 80% at 550 nm and low emissivity in IR.

• Journal of Ocean Engineering and Technology
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• v.25 no.1
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• pp.39-43
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• 2011

This study has lowered the specific resistance by coating a thin film layer of Ag, playing the role of the electron donor on the ZnO that is used usefully for the transparent conductive oxides. Presently, this study has examined the transmittance and electric characteristics according to the thickness of the Ag thin film layer. Also, this study has observed the transmittance and electric characteristics according to the uppermost ZnO thin film layer of ZnO/Ag/ZnO symmetric film and has conducted the theoretical investigation. In order to observe the transmittance and electric characteristics according to the thickness of the Ag thin film layer and the uppermost ZnO thin film layer, this study conducted the film deposition at room temperature while making use of the DC magnetron sputtering system. In order to see the changes in the thickness of the Ag thin film layer, this study coated a thin film while increasing by 4nm; and, in order to see the changes in the thickness of uppermost ZnO thin film layer, it performed the thin film coating by increasing by 5nm. From the experimental result, the researchers observed that the best transmittance could be obtained when the thickness of the Ag thin film layer was 8nm, but the resistance and mobility increased as the thickness got larger. On the other hand, when the thickness of the uppermost ZnO thin film layer was 20nm, the experiment yielded the best transmittance with excellent electric characteristics. Also, when compared the ZnO/Ag asymmetric film with the ZnO/Ag/ZnO symmetric film, the ZnO/Ag asymmetric film showed better transmittance and electric characteristics.

• Journal of Korea Foundry Society
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• v.28 no.4
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• pp.184-189
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• 2008

Ag-Cd alloy has been widely used as an electrical contact material, since Ag-Cd alloy has a good wear resistance and stable contact resistance. But nowadays Ag-Cd alloy is not considered as electrical contact material any more due to detrimental effect on environments. Currently, active researches are being performed on ($Ag-SnO_2$ and $Ag-SnO_{2}-In_{2}O_{3}$) as an alternative solution which can fix the remaining environmental problems. However, $In_{2}O_{3}$ is relatively expensive and Ag-Sn alloy has low wear resistance. Our recent research results show that Ag-X%Zn-Y%Sn has similar physical and chemical properties. In the present study, so we tried to change and to optimize the Zn oxide content to over 6 wt% and Sn oxide content with 0.5, 1.0, 1.5 wt%. Results obtained from the experiments on the Ag-X%ZnO-Y%$SnO_2$ are discussed.

• Current Optics and Photonics
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• v.3 no.2
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• pp.135-142
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• 2019

We report the precipitation of ZnO nanocrystals, Ag-clusters, and Ag nanoparticles in Ag/Er/Yb doped borate glasses by furnace annealing and $CO_2$ laser annealing. The XRD analysis revealed the precipitation of ZnO and Ag phases. The absorption spectra, the TEM and energy dispersive spectroscopy (EDS) revealed the incorporation of Er and Yb ions into ZnO nanocrystals formed by a laser technique and showed the surface plasmon band of Ag nanoparticles. The down-converted blue emission intensity of $Er^{3+}$ ions obtained under 365 nm excitation was enhanced by more than a hundred times in the glass treated by furnace annealing, mainly due to the energy transfer from Ag-clusters. Moreover, we discussed the contribution of Ag nanoparticles and defects to emission characteristics in the glasses treated by two annealing techniques. Up-conversion emissions of the $Er^{3+}$ ions under 980 nm excitation were enhanced due to the incorporation of $Er^{3+}$ and $Yb^{3+}$ ions into ZnO nanocrystals after thermal treatments.

• Advances in materials Research
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• v.11 no.3
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• pp.225-235
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• 2022

It includes the synthesis of pristine ZnO nanoparticles and a series of Ag-doped zinc oxide nanoparticles was carried out by reflux method by varying the amount of silver (1, 3, 5, 7 and 9% by mol.). The morphology of these nanoparticles was investigated by SEM, XRD and FT-IR techniques. These techniques show that synthesized particles are homogenous spherical nanoparticles having an average particle size of about 50-100 nm along with some agglomeration. The photocatalytic activity of the ZnO nanoparticles and Ag doped ZnO nanoparticles were investigated via photodegradation of methylene blue (MB) as a standard dye. The data from the photocatalytic activity of these nanoparticles show that 7% Ag-doped ZnO nanoparticles exhibit much enhanced photocatalytic activity as compared to pristine ZnO nanoparticles and other percentages of Ag-doped ZnO nanoparticles. Furthermore, 7% Ag-doped ZnO was made composites with sulfur-doped graphitic carbon nitride by physical mixing method and a series of nanocomposites were made (3.5, 7.5, 25, 50, 75% by weight). It was observed that the 25% composites exhibited better photocatalytic performance than pristine S-g-C 3 N 4 and pure 7% Ag-doped ZnO. Tauc's plot also supports the photodegradation results.

• Transactions on Electrical and Electronic Materials
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• v.16 no.6
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• pp.334-337
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• 2015

Pure ZnO, ZnO nanowires doped with 3 wt.% Ga (3GZO) and doped with 3 wt.% Ag (3SZO) were grown by a hot-walled pulse laser deposition (HW-PLD) technique. The optical and chemical properties of Ga and Ag doped nanowires was analyzed. Nanowires were determined to be under 200 nm in diameter and several μm in length. Change of significant resistance was observed and the gas detection sensitivities of ZnO, 3GZO and 3SZO nanawires were compared. The sensitivities of ZnO, 3GZO, and 3SZO nanowire sensors were measured at 300℃ for 1 ppm of ethanol gas at 97%, 48%, and 203%, respectively.

• Journal of the Korean Society for Heat Treatment
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• v.25 no.2
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• pp.85-89
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• 2012

Transparent conductive ZnO/Ag/ZnO (ZAZ) multilayer films were deposited by Radio frequency (RF) magnetron sputtering and direct current (DC) magnetron sputtering. The effects of post deposition vacuum annealing temperature on the structural, electrical and optical properties of the ZAZ multilayer films were investigated. The thickness of ZAZ films is kept constant at ZnO 50 nm/Ag 5nm/ZnO 45 nm, while the vacuum annealing temperatures were varied from 200 and $400^{\circ}C$, respectively. As-deposited ZAZ films exhibit a sheet resistance of $6.1{\Omega}/{\Box}$ and optical transmittance of 72.7%. By increasing annealing temperature to $200^{\circ}C$, the resistivity decreased to as low as $5.3{\Omega}/{\Box}$ and optical transmittance also increased to as high as 82.1%. Post-deposition annealing of ZAZ multilayer films lead to considerably lower electrical resistivity and higher optical transparency, simultaneously by increased crystallization of the films.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.433-434
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• 2007

We prepared ZnO thin films coating Ag on glass substrates at room temperature by using facing targets sputtering (FTS) method. ZnO thin films were deposited with same conditions. Ag with various thickness of thin films were used as intermediate layers. The electrical, optical and crystallographic properties of thin films were investigated by Four-Point probe, UV/VIS spectrometer and XRD. From the results, we could confirm that the thickness of Ag layer changes the electrical and optical performances of the multilayers.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.397-397
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• 2007

Multilayer transparent electrodes, having a much lower electrical resistance than the widely used transparent conducting oxide electrodes, were prepared by using radio frequency magnetron sputtering. The multilayer structure consisted of five layers, indium tin oxided(ITO)/zinc oxide(ZnO)/Ag/oxide(ZnO)/ITO. With about 50nm thick ITO films, the multilayer showed a high optical transmittance in the visible range of the spectrum and had color neutrality. The electrical and optical properties of ITO/ZnO/Ag/ZnO/ITO multilayer were changed mainly by Ag film properties, which were affected by the deposition process of the upper layer. Especially ZnO layer was improved to adhesion of Ag and ITO. A high quality transparent electrode, having a resistance as low as and a high optical transmittance of 91% at 550nm, was obtained. It could satisfy the requirement for the flexible OLED and LCD.

• The korean journal of orthodontics
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• v.53 no.1
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• pp.16-25
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• 2023

Objective: We aimed to evaluate the cell viability and antimicrobial effects of orthodontic bands coated with silver or zinc oxide nanoparticles (nano-Ag and nano-ZnO, respectively). Methods: In this experimental study, 30 orthodontic bands were divided into three groups (n = 10 each): control (uncoated band), Ag (silver-coated band), and ZnO (zinc oxide-coated band). The electrostatic spray-assisted vapor deposition method was used to coat orthodontic bands with nano-Ag or nano-ZnO. The biofilm inhibition test was used to assess the antimicrobial effectiveness of nano-Ag and nano-ZnO against Streptococcus mutans, Lactobacillus acidophilus, and Candida albicans. Biocompatibility tests were conducted using the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay. The groups were compared using oneway analysis of variance with a post-hoc test. Results: The Ag group showed a significantly higher reduction in the number of L. acidophilus, C. albicans, and S. mutans colonies than the ZnO group (p = 0.015, 0.003, and 0.005, respectively). Compared with the control group, the Ag group showed a 2-log₁₀ reduction in all the microorganisms' replication ability, but only S. mutants showed a 2-log₁₀ reduction in replication ability in the ZnO group. The lowest mean cell viability was observed in the Ag group, but the difference between the groups was insignificant (p > 0.05). Conclusions: Coating orthodontic bands with nano-ZnO or nano-Ag induced antimicrobial effects against oral pathogens. Among the nanoparticles, nano-Ag showed the best antimicrobial activity and nano-ZnO showed the highest biocompatibility.