• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.35 no.1
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• pp.32-36
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• 2022

AGZO thin films were deposited on glass substrates using RF magnetron sputtering system under Ar flow rates, and their structural, electrical, and optical properties were analyzed systematically. As a result of the XRD pattern, the peak of the (002) (2θ≈33.7˚) orientation was observed, and it was found to have a hexagonal wurtzite structure. The sheet resistance of Ar 5 sccm was 3.073×10² Ω/sq and showed the best electrical properties because of the improvement of mobility due to the increase of the grain size and the variation of RMS roughness. In addition, the average transmittance was more than 90% for all samples, which demonstrated good optical properties. It is expected that the TCO characteristics can be improved by controlling Ar flow rates, and this will increase the efficiency of photoelectronic devices such as OLED and solar cells.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.4
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• pp.289-293
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• 2013

We have studied structural, optical, and electrical properties of the Ga-doped ZnO (GZO) thin films being usable in transparent conducting oxides. The GZO thin films were deposited on the corning 1737 glass plate by the RF magnetron sputtering system. To find optimal properties of GZO for transparent conducting oxides, the Ar gas in sputtering process was varied as 40, 60, 80 and 100 sccm, respectively. As reaction gas decreased, the crystallinity of GZO thin film was increased, the optical bandgap of GZO thin film increased. The transmittance of the film was over 80% in the visible light range regardless of the changes in reaction gas. The measurement of Hall effect characterizes the whole thin film as n-type, and the electrical property was improved with decreasing reaction gas. The structural, optical, and electrical properties of the GZO thin films were affected by Ga dopant content in GZO thin film.

• Korean Journal of Materials Research
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• v.19 no.3
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• pp.125-131
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• 2009

In this report, the structural and optical properties of sol-gel derived $Mg_xZn_{1-x}O$ thin films upon changes in the composition and annealing temperature were investigated. The $Mg^{2+}$ content and the annealing temperature were varied in the range of $0{\leq}x{\leq}0.35$ and $400^{\circ}C{\leq}T{\leq}600^{\circ}C$, respectively. The films exhibited a hexagonal wurtzite structure of a polycrystalline nature. The optical transmittance exceeded 85% and the optical band gap of the film was tuned as high as 3.84 eV at a value of x = 0.35 (annealed at $400^{\circ}C$), which was evidently the maximum $Mg^{2+}$ content for the single-phase polycrystalline $Mg_xZn_{1-x}O$ thin films prepared in this experiment. The optical band gap and photoluminescence emission were tailored to the higher energy side while maintaining crystallinity without a significant change of the lattice constant.

• Bulletin of the Korean Chemical Society
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• v.33 no.4
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• pp.1235-1241
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• 2012

Aluminium (Al)-doped zinc oxide (AZO) thin films with different Al concentrations were prepared by the solgel spin-coating method. Optical parameters such as the optical band gap, absorption coefficient, refractive index, dispersion parameter, and optical conductivity were studied in order to investigate the effects of the Al concentration on the optical properties of AZO thin films. The dispersion energy, single-oscillator energy, average oscillator wavelength, average oscillator strength, and refractive index at infinite wavelength of the AZO thin films were found to be affected by Al incorporation. The optical conductivity of the AZO thin films also increases with increasing photon energy.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.140-140
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• 1999

Ti/Ni multilayered films (MLF) are ideal for neutron optics particularly in neutron guides and focusing devices. This system also possesses the tendency of amorphization through a solid-state reaction (SSR). This behaviors are closely related to the electronic structures and both magneto-optical (MO) and optical properties of metals depend strongly on their electron energy structures. Mutual inter-diffusion of the Tin and Ni atoms in the MLF caused by a low temperature annealing should decrease the thickness of pure Ni, as well as change the chemical and atomic order in the reactive zone. The application of the MO spectroscopy to the study of SSR in the MLF allows us to obtain an additional information on the changes in the atomic and chemical orders in the interface region. The optical one has no restriction on the magnetic state of the constituent sublayers. Therefore, the changes in magnetic, MO and optical properties of the Ti/Ni MLF due to SSR can be expected. To the best of our knowledge, the MO and optical spectroscopies were not used for this purpose. SSR has been studied in the series of the Ti/Ni MLFs with bilayer periods of 0.65-22.2nm and constant ratio of the Ti to Ni sublayers thickness by using MO and optical spectroscopies as well as an x-ray diffraction. The experimental MO and optical spectra are compared with the computer-simulated spectra, assuming various interface models. The relative changes in the x-ray diffraction spectra and MO properties of the Ti/Ni MLF caused by annealing are bigger for the multilayers with "thick" sublayers, or the SSR with the formation of amorphous alloy takes place mainly in the Ti/Ni multilayers with "thick" sublayers, while in the nominal threshold thickness of the Ni-sublayer for the observation of the equatorial Kerr effect in the as-deposited and annealed Ti/Ni MLFs of about 3.0 and 4.5nm thick is explained by the formation of amorphous alloy during the deposition or the formation of the nonmagnetic alloyed regions between pure components as a result of the SSR. For the case of Ti/Ni MLF the MO approach is more sensitive for the determination of the thickness of the reacted zone, while x-ray diffraction is more useful for structural analyses.structural analyses.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.828-830
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• 2000

Various substrates were compared for the investigation of the optical properties of ZnO thin films. ZnO thin films have been deposited on (100) p-type silicon substrates and (001) sapphire substrates by pulsed laser deposition technique using a Nd:YAG laser with the wavelength of 355 nm. Oxygen and nitrogen gases were used as ambient gases. Substrate temperatures were varied in the range of 200$^{\circ}C$ to 600$^{\circ}C$ at a fixed ambient gas pressure of 350 mTorr. ZnO films have been deposited on various substrates, such as Si and sapphire wafers. We have investigated substrate effect on the optical and structural properties of ZnO thin films using X-ray diffraction (XRD) and photoluminescence (PL).

• Journal of the Optical Society of Korea
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• v.10 no.1
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• pp.1-10
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• 2006

Optical transparency and high diffraction efficiency are two essential factors for high performance of the photopolymer. Optical transparency mainly depends on the miscibility between polymer binder and photopolymerized polymer, while diffraction efficiency depends on the refractive index modulation between polymer binder and photopolymerized polymer. For most of organic materials, the large refractive index difference between two polymers accompanies large structural difference that leads to the poor miscibility and thus poor optical quality via light scattering. Therefore, it is difficult to design a high-performance photopolymer satisfying both requirements. In this work, first, we prepared a new phase-stable photopolymer (PMMA) with large refractive index modulation and investigated the optical properties. Our photopolymer is based on modified poly (methyl methacrylate) as a polymer binder, acryl amide as a photopolymerizable monomer, triethanolamine as initiator, and yellow eosin as a photosensitizer at 532 nm. Diffraction efficiency over 85% and optical transmittance over 90% were obtained for the photopolymer. Second, Organic-inorganic nanocomposite films were prepared by dispersing an aromatic methacrylic monomer and a photo- initiator in organic-inorganic hybrid sol-gel matrices. The film properties could be controlled by optimizing the content of an organically modified silica precursor (TSPEG) in the sol-gel matrices. The photopolymer film modified with the organic chain (TSPEG) showed high diffraction efficiency (> 90%) under an optimized condition. High diffraction efficiency could be ascribed to the fast diffusion and efficient polymerization of monomers under interference light to generate refractive index modulation. The TSPEG modified photopolymer film could be successfully used for holographic memory.

• Proceedings of the Materials Research Society of Korea Conference
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• 2001.11a
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• pp.158-158
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• 2001

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.699-700
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• 2013

Aluminum and hydrogen doped zinc oxide (AZHO) films were prepared by r.f. magnetron sputtering. The structural, electrical, and optical properties of the AHZO films were investigated in terms of the annealing conditions to study the thermal stability. The XRD measurements revealed that the degree of c-axis orientation was decreased and the crystallintiy of the films was deteriorated by the heat treatment. The electrical resistivity was significantly increased when the films were annealed at higher temperature. Although the optical transmittance of AHZO films didn't highly changed by heat treatment, the optical band gap was reduced, regardless of annealing temperature and duration. The thermal stability of AHZO films was worse compared to AZO films.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1246_1247
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• 2009

Effects of hydrogen and oxygen additives on structural, optical, and electrical properties of ZnO films were extensively examined. ZnO films were deposited using RF sputtering by varying the gas mixing ratio of $H_2$ and $O_2$. Optical transmittances at visible region, electrical resistivities, and micro-structures of ZnO films were characterized in terms of the kind and amount of additive gases. It was observed that the material properties of ZnO films required for their use in transparent thin film transistors, such as approximately $10^3{\Omega}cm$ in resistivity and higher than 85% in transmittance, can be achieved by controlling the gas mixing ratio of $O_2/H_2$ (sccm) in the range of 2/2~2/8.