• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.12
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• pp.1008-1015
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• 2001

Thin films of vanadium oxide(VO$\_$x/) have been deposited by r.f. magnetron sputtering from V$_2$O$\_$5/ target in gas mixture of argon and oxygen. The oxygen/(oxygen+argon) partial pressure ratio is changed from 0% to 8%. Crystal structure, chemical composition, bonding, optical and electrical properties of films sputter-deposited under different oxygen gas pressures are characterized through XPS, AES, RBS, FTIR, optical absorption and electrical conductivity measurements. V$_2$O$\_$5/ and lower oxides co-exist in sputter-deposited films and as the oxygen partial pressure is increased the films become more stoichiometric V$_2$O$\_$5/. The increase of O/V ratio with increasing oxygen gas pressure is attributed to the partial filling of oxygen vacancies through diffusion. It is observed that the oxygen atoms located on the V-O plane of V$_2$O$\_$5/ layer participate more readily in the oxidation process. With increasing oxygen gas pressure indirect and direct optical band gaps are increased, but thermal activation energies are decreased.

• Journal of Surface Science and Engineering
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• v.51 no.2
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• pp.126-132
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• 2018

SnS thin films with different substrate temperatures ($150 {\sim}300^{\circ}C$) as process parameters were grown on soda-lime glass substrates by RF magnetron sputtering. The effects of substrate temperature on the structural and optical properties of SnS thin films were investigated by X-ray diffraction (XRD), Raman spectroscopy (Raman), field-emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDS), and Ultraviolet-visible-near infrared spectrophotometer (UV-Vis-NIR). All of the SnS thin films prepared at various substrate temperatures were polycrystalline orthorhombic structures with (111) planes preferentially oriented. The diffraction intensity of the (111) plane and the crystallite size were improved with increasing substrate temperature. The three major peaks (189, 222, $289cm^{-1}$) identified in Raman were exactly the same as the Raman spectra of monocrystalline SnS. From the XRD and Raman results, it was confirmed that all of the SnS thin films were formed into a single SnS phase without impurity phases such as $SnS_2$ and $Sn_2S_3$. In the optical transmittance spectrum, the critical wavelength of the absorption edge shifted to the long wavelength region as the substrate temperature increased. The optical bandgap was 1.67 eV at the substrate temperature of $150^{\circ}C$, 1.57 eV at $200^{\circ}C$, 1.50 eV at $250^{\circ}C$, and 1.44 eV at $300^{\circ}C$.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.12
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• pp.1134-1139
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• 2006

Electrical, optical, and structural properties of indium zinc oxide (IZO) anode films grown by a RF magnetron sputtering were investigated as functions of RF power and working pressure in pure Ar ambient. To investigate electrical, optical and structural properties of IZO anode films, 4-point probe and UV/VIS spectrometry, and X-ray diffraction (XRD) were performed, respectively. A sheet resistance of $15.2{\Omega}/{\square}$, average transmittance above 80 % in visible range, expecially above 85 % in 550 nm, and root mean square roughness of 1.13 nm were obtained from optimized IZO anode films grown in oxygen free ambient. All samples show amorphous structure regardless of RF power and working pressure due to low substrate temperature. In addition, XPS depth profile obtained from IZO/PES exhibits that there is no obvious evidence of interfacial reaction between IZO and PES substrate. Furthermore, current-voltage-luminance of the flexible phosphorescent flexible OLEDs fabricated on IZO anode shows dependence on sheet resistance of the IZO anode. These results indicate that the IZO anode is a promising candidate to substitute conventional ITO anode for high-quality flexible displays.

• Proceedings of the KIEE Conference
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• 2005.11a
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• pp.27-29
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• 2005

ZnO and phosphorus doped ZnO thin films (ZnO:P) are deposited by pulsed laser deposition grown on (001) $Al_{2}O_{3}$. ZnO/ZnO:P/ZnO/$Al_{2}O_{3}$ (multi-layer) structure was used for phosphorus doped ZnO fabrication. This multi-layer structure thin film was annealed at $400^{\circ}C$ for 40 min. The electron concentration of that was changed from $10^{19}$ to $10^{16}/cm^{-3}$ after annealing. ZnO thin films with encapsulated structure showed the enhanced structural and optical properties than phosphorus doped ZnO without encapsulated layer. In this study, encapsulated ZnO structure was suggested to enhance electrical, structural and optical properties of phosphorus doped ZnO thin film and it was identified that encapsulated structure could be used to fabricate high quality phosphorus doped ZnO thin film.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.412-413
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• 2007

We report on the electrical, optical, and structural properties of indium zinc tin oxide (IZTO) anode films grown at room temperature on glass substrate. The IZTO anode films grown by a RF magnetron sputtering were investigated as functions of RF power, working pressure, and process time in pure Ar ambient. To investigate electrical, optical and structural properties of IZTO anode films, 4-point probe, Hall measurement, UV/Vis spectrometer, Field Emission Scanning Electron Microscopy (FE-SEM), and X-ray diffraction (XRD) were performed, respectively. A sheet resistance of $13.88\;{\Omega}/{\square}$, average transmittance above 80 % in visible range were obtained from optimized IZTO anode films grown on glass substrate. These results shown the amorphous structure regardless of RF power and working pressure due to low substrate temperature.

• Applied Microscopy
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• v.51
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• pp.14.1-14.11
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• 2021

Melanin has been a widely researched pigment by scientists for decades as it is undoubtedly the most ubiquitous and ancient pigment found in nature. Melanin plays very signifcant roles in structural plumage colors in birds: it has visible light-absorbing capabilities, and nanoscale structures can be formed by self-assembling melanin granules. Herein, we review recent progress on melanin-based structural coloration research. We hope that this review will provide current understanding of melanin's structural and optical properties, natural coloration mechanisms, and biomimetic methods to implement artifcial melanin-based structural colors.

• Journal of the Korean Ceramic Society
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• v.39 no.2
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• pp.109-112
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• 2002

The structural and optical features of Porous Silicon(PS) were investigated; the porous silicon was prepared by electrochemical etching of silicon wafers in HF solution. The morphologies and Photoluminescece(PL) features of the PS were investigated in terms of etching time, current density and aging conditions. The average pore diameter and pore depth were determined by current density and etching time, respectively. As-prepared PS exhibited the maximum PL peak at the wavelength of ∼ 450 nm. The degree of deviation from as-prepared PS during aging treatment seemed to depend on the microstructure as well as morphology of the PS. It is found that etching current density played an important role on the microstructural features of the PS.

• The Research Journal of the Costume Culture
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• v.12 no.1
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• pp.12-27
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• 2004

The Tuck, an important component of modem clothing design, was analyzed through various sources of literature comprised chiefly of domestic and imported fashion magazines from 2000 to 2003. The results were as follows: 1) The Tuck was organized in horizontal, perpendicular, oblique and radial directions. Application methods included repetition, gradation, radial arrangement, sequence and alternation of individual lines. 2) The Tuck was found in a variety of forms and uses. But due to structural characteristics, its function is more psychological and aesthetic than functional. The aesthetic properties of the Tuck included rhythm, optical illusion, abstraction, and material. The structural property of the Tuck occasionally substituted bust or waist darts. 3) The individuality and originality of the Tuck was used in unpredictable ways to give spatial ornamentality and emphasis on material. This enabled aesthetically unique designs to arise. To summarize, the Tuck, a component of clothing design as a formative art, was used in a variety of methods towards developing creative clothing design.

• Current Photovoltaic Research
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• v.1 no.2
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• pp.97-102
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• 2013

Aluminum-doped zinc oxide (AZO) thin films were prepared by dc magnetron sputtering at room temperature and the effect of heat treatment on the structural, electrical and optical properties of the films were examined. As the annealing temperature and time increased, the resistivity decreased and the transmittance improved. All AZO films had c-axis oriented (002) plane of ZnO, regardless of the annealing process employed. As the annealing temperature and time increased, the crystallinity of AZO thin films increased due to the formation of a new ZnO phase in which Al was substituted for Zn. However, at the high annealing temperature of $400^{\circ}C$, the resistivity of the films increased via separation of Zn and Al from ZnO phase due to their low melting points. X-ray diffraction, field emission scanning electron micrograph and Hall effect measurement confirmed the formation of uniformly distributed new grains of ZnO substituted with Al. The variation of Al contents in AZO films was shown to be the primary factor for the changes in resistivity and carrier concentration of the films.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.589-589
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• 2012

Indium sulfide thin films have been grown onto glass substrates using radio frequency magnetron sputtering at room temperature. The as-deposited film were annealed in nitrogen atmosphere at different temperatures of 100, 200, 300, 400 and $500^{\circ}C$ with an 1 h annealing time. The effect of annealing temperature on composition, structure, morphology and optical properties of the as-grown In2S3 films has been studied. The XRD results indicate that the as-deposited films are composed by a mixture of both cubic ${\alpha}$ and ${\beta}$ crystalline phases, with some fraction of tetragonal phase. The thermal annealing on the films produces the conversion of the cubic crystalline phases to the tetragonal ${\beta}$ one and a crystalline reorientation of the latter phase. The surface morphological analysis reveals that the films grown at $300^{\circ}C$ have an average grain size of ~ 58 nm. These films show a S/In ratio of 0.99. The optical band gap is found to be direct and the films grown at $300^{\circ}C$ shows a higher optical transmittance of 80% and an energy band gap of 2.52 eV.