The present polymer have a conjugated polymer backbone system with the designed substituents. The photoluminescence peak of polymer was observed at 525nm, which is corresponded to the photon energy of 2.36 eV and the band gap of poly(EBA) was 2.38 eV. The cyclovoltamograms of the polymer exhibited the irreversible electrochemical behaviors. It was found that the kinetics of the redox process of this conjugated polymer might be mainly controlled by the diffusion process from the experiment of the oxidation current density of polymer versus the scan rate.

New carbazole derivatives including coumarin moiety, 7-(3-Carbazol-9-yl-phenyl)-chromen-2-one (C-PCa), 7-(9-Phenyl-9H-carbazol-3-yl)-chromen-2-one (PCa-C), 7-[9-(3-Carbazol-9-yl-phenyl)-9H-carbazol-3-yl]-chromen-2-one (PDCa-C) were synthesized by Suzuki reaction. In film state, maximum UV-Vis absorption of three synthesized compounds appeared in the range 331 to 345 nm. PL spectrum of C-PCa, PCa-C and PDCa-C showed miximum emission wavelength of 449, 467 and 467 nm, respectively. C-PCa showed white emission of current efficiency of 1.16 cd/A, power efficiency of 0.59 lm/W and C.I.E of (0.26, 0.33). PCa-C showed current efficiency of 1.13 cd/A, power efficiency of 0.62 lm/W and C.I.E of (0.19, 0.27). PDCa-C showed the highest current efficiency of 1.34 cd/A, power efficiency of 0.62 lm/W and C.I.E of (0.18, 0.23).

Surface morphology and optical properties such as transmittance and haze effect of glass etched by physical and chemical etching processes were investigated. The physical etching process was carried out by pen type sandblasting process with 15~20 μm dia. of Al2O3 media; the chemical etching process was conducted using HF-based mixed etchant. Sandblasting was performed in terms of variables such as the distance of 8 cm between the gun nozzle and the glass substrate, the fixed air pressure of 0.5bar, and the constant speed control of the specimen stage. The chemical etching process was conducted with mixed etching solution prepared by combination of BHF (Buffered Hydrofluoric Acid), HCl, and distilled water. The morphology of the glass surface after sandblasting process displayed sharp collision vestiges with nonuniform shapes that could initiate fractures. The haze values of the sandblasted glass were quantitatively acceptable. However, based on visual observation, the desirable Anti-Glare effect was not achieved. On the other hand, irregularly shaped and sharp vestiges transformed into enlarged and smooth micro-spherical craters with the subsequent chemical etching process. The curvature of the spherical crater increased distinctly by 60 minutes and decreased gradually with increasing etching time. Further, the spherical craters with reduced curvature were uniformly distributed over the etched glass surface. The haze value increased sharply up to 55 % and the transmittance decreased by 90 % at 60 minutes of etching time. The ideal haze value range of 3~7 % and transmittance value range of above 90 % were achieved in the period of 240 to 720 minutes of etching time for the selected concentration of the chemical etchant.

Recycled cenosphere, which is a hollow shaped particle from fly ash, has become attractive as a building material due to its light weight and excellent heat insulation and soundproof properties. In this paper, we investigated the effect of cenosphere size on the physical and optical properties. High brightness of cenosphere as raw material is required for a wide range of ceramics applications, particularly in fields of building materials and industrial ceramic tiles. Cenospheres were sorted by particle size; the microstructure was analyzed according to the cenosphere size distribution. Cenospheres were generally composed of quartz, mullite, and amorphous phase. Colour measurement corresponding to chemical composition revealed that the contents of iron oxide and carbon in the cenospheres were the major factors determining the brightness of the cenospheres.

The effects of electron beam(EB) irradiation on the electrical and optical properties of InGaZnO(IGZO) thin films fabricated using a sol-gel process were investigated. As the EB dose increased, the electrical characteristic of the IGZO TFTs changed from semiconductor to conductor, and the threshold voltage values shifted to the negative direction. X-ray photoelectron spectroscopy analysis of the O 1s core level showed that the relative area of oxygen vacancies increased from 14.68 to 19.08 % as the EB dose increased from 0 to 1.5 × 1016 electrons/cm2. In addition, spectroscopic ellipsometer analysis showed that the optical band gap varied from 3.39 to 3.46 eV with increasing EB dose. From the result of band alignment, it was confirmed that the Fermi level(EF) of the sample irradiated with 1.5 × 1016 electrons/cm2 was located at the closest position to the conduction band minimum(CBM) due to the increase of electron carrier concentration

Photoelectron-hole separation efficiency plays an important role in the enhancement of the photocatalytic activity of photocatalysts towards the degradation of organic molecules. In this study, TiO2/TiOF2 heterostructured composite powders with suitable band structures, which structures are able to separate photoelectron-hole pairs, have been synthesized using a simple and versatile ultrasonic spray pyrolysis process. In addition, their phase volume fractions have been controlled by varying the pyrolysis temperature from 400 oC to 800 oC. The structural and optical properties of the synthesized powders have been characterized by X-ray diffraction, scanning electronic microscopy and UV-vis spectroscopy. The powder with a phase volume ratio close to 1, compared with single TiOF2 and other composite powders with different phase volume fractions, was found to have superior photocatalytic activity for the degradation of rhodamine B. This result shows that the TiO2/TiOF2 heterostructure promotes the separation of the photoinduced electrons and holes and that this powder can be applicable to environmental cleaning applications.

적색 K2SiF6:Mn4+ 형광체는 SiO2 in/HF/KMnO4H2O solution 용액의 산화환원 반응에 의해 합성된다. 이 형광체 는 450 nm 이하의 파장에서 여기되어 Mn4+의 2Eg → 4A2g에 의해 반치폭이 10 nm인 약 634 nm의 적색 빛을 발광한다. 입자의 크기는 약 5 ㎛이고 결정구조는 Fm-3m (225)의 공간군을 가지는 입방정계이다 (JCPDS85-1382). 온도의존 발광 스펙트럼에서는 약 175 ℃에서의 발광강도가 상온에서보다 66 %까지 감소하였다. 이 형광체는 청색 발광을 하는 InGaN LED에 의해 효과적으로 여기 될 수 있어서 녹색이나 황색 형광체와 함께 사용하여 연색지수가 높은 백색 LED를 만들 수 있다.

Quantum dots (QDs) are capable of controlling the typical emission and absorption wavelengths because of the bandgap widening effect of nanometer-sized particles. These phosphor particles have been used in optical devices, photovoltaic devices, advanced display devices, and several biomedical complexes. In this study, we synthesize ZnSe QDs with controlled surface defects by a heating-up method. The optical properties of the synthesized particles are analyzed using UV-visible and photoluminescence (PL) measurements. Calculations indicate nearly monodisperse particles with a size of about 5.1 nm at 260℃ (full width at half maximum = 27.7 nm). Furthermore, the study results confirm that successful doping is achieved by adding Eu3+ preparing the growth phase of the ZnSe:Eu QDs when heating-up method. Further, we investigate the correlation between the surface defects and the luminescent properties of the QDs.

We investigate optical properties of amorphous alumina (Al2O3) dust grains in the envelopes around O-rich asymptotic giant branch (AGB) stars using laboratory measured optical data. We derive the optical constants of amorphous alumina over a wide wavelength range that satisfy the Kramers- Kronig relation and reproduce the laboratory data. Using the amorphous alumina and silicate dust, we compare the radiative transfer model results with the observed spectral energy distributions. Comparing the theoretical models with observations on various IR two-color diagrams for a large sample of O-rich AGB stars, we find that the amorphous alumina dust (about 10-40%) mixed with amorphous silicate better models the observed points for the O-rich AGB stars with thin dust envelopes.

In this study, we fabricated high quality color conversion component with green/red phosphor and low melting glass frit. The color conversion component was prepared by placing the green and red phosphor layer on slide glass via screen printing process. The properties of color conversion component could be controlled by changing coating sequence, layer thickness and heat treatment temperature. We discovered that optical properties of color conversion component were generally determined by the lowest layer. On the other hand, the heat treatment temperature also affected to correlated color temperature (CCT) and color rending index (CRI). The color conversion component with a green (lower) - red (upper) layer which was sintered at 550 oC showed the best optical properties: CCT, CRI and luminance efficacy were 3340 K, 78, and 56.5 lm/w, respectively.

목 적: Iodine을 수송매체로 사용한 화학수송법으로 성장시킨 CdS, CdS : Co2+ 및 CdS : Er3+단결정의 광학적 특성연구를 하였다. 방 법: CdS, CdS : Co 및 CdS : Er 단결정을 성장시키기 위하여 고순도(99.9999 %)의 cadmium, sulfur 를 mole비로 칭량하고 수송물질로 iodine(순도 99.99%)을 함께 준비된 석영관 안에 넣고, 석영관 내부의 진 공을 5×10-6torr로 유지하면서 봉입하여 성장용 ampoule을 만들었다. 단결정을 성장시키기 위하여 시료 출발 측을 900 ℃, 성장 측을 700 ℃로 하여 7일간 성장시켰다. 성장된 단결정에서 iodine 을 제거하기 위하여 출발 측의 전원을 차단하고 성장 측의 온도를 250℃에서 10 시간동안 유지하여 전원을 끊고 실온까지 서냉하여, CdS, CdS : Co 및 CdS : Er단결정을 성장시켰다. 성장된 단결정의 결정구조는 X-ray diffractometer를 사용하여 X선 회절선을 측정하였고, 광흡수 특성은 UV-VIS-NIR spectrophotometer 로 측정하였다. 결과 및 고찰: XRD로 측정한 X선 회절무늬 peak 해석으로부터 구한 CdS 및 CdS : Co2+(2mole%) 단결정의 결정구조는 defect chalcopyrite 구조이었으며 CdS : Er3+(2mole%) 단결정은 hexagonal 구조였다. 에너지 띠 간격은 직접 전이형 밴드구조를 나타냈다. 결 론: 성장된 CdS 및 CdS : Co2+(2mole%) 단결정의 결정구조는 defect chalcopyrite 구조이었으며, 격자 상수는 CdS 단결정의 경우 a = 4.139Å, c = 6.716Å이였고, 불순물로 cobalt를 첨가한 CdS : Co2+(2mole%) 단결정의 경우 a = 4.141Å, c = 6.720Å이였으며, 또한 erbium을 첨가한 CdS : Er3+(2mole%) 단결정의 구조 는 hexagonal 구조이었으며, 격자상수는 a = 4.135Å, b = 4.135Å, c = 6.706Å이었다. 298K에서 순수한 CdS 단결정의 에너지 띠 간격은 2.422e V이었고, 불순물로 전이금속인 cobalt(2mole%) 첨가할 때 에너지 띠 간격은 2.331e V, 또한 희토류금속인 erbium(2mole%) 첨가한 경우 에너지 띠 간격은 2.230e V 이었다.

Sb-doped SnO2(ATO) thin films were prepared using electrospinning. To investigate the optimum properties of the electrospun ATO thin films, the deposition numbers of the ATO nanofibers(NFs) were controlled to levels of 1, 2, 4, and 6. Together with the different levels of deposition number, the structural, chemical, morphological, electrical, and optical properties of the nanofibers were investigated. As the deposition number of the ATO NFs increased, the thickness of the ATO thin films increased and the film surfaces were gradually densified, which affected the electrical properties of the ATO thin films. 6 levels of the ATO thin film exhibited superior electrical properties due to the improved carrier concentration and Hall mobility resulting from the increased thickness and surface densification. Also, the thickness of the samples had an effect on the optical properties of the ATO thin films. The ATO thin films with 6 deposited levels displayed the lowest transmittance and highest haze. Therefore, the figure of merit(FOM) considering the electrical and optical properties showed the best value for ATO thin films with 4 deposited levels.

Fluorine-doped SnO2 (FTO) thin film/Ag nanowire (NW) double layers were fabricated by means of spin coating and ultrasonic spray pyrolysis. To investigate the optimum thickness of the FTO thin films when used as protection layer for Ag NWs, the deposition time of the ultrasonic spray pyrolysis process was varied at 0, 1, 3, 5, or 10 min. The structural, chemical, morphological, electrical, and optical properties of the double layers were examined using X-ray diffraction, X-ray photoelectron spectroscopy, field-emission scanning electron microscopy, transmission electron microscopy, the Hall effect measurement system, and UV-Vis spectrophotometry. Although pure Ag NWs formed isolated droplet-shaped Ag particles at an annealing temperature of 300 oC, Ag NWs covered by FTO thin films maintained their high-aspect-ratio morphology. As the deposition time of the FTO thin films increased, the electrical and optical properties of the double layers degraded gradually. Therefore, the double layer fabricated with FTO thin films deposited for 1 min exhibited superb sheet resistance (~14.9Ω/□), high optical transmittance (~88.6 %), the best FOM (~19.9 × 10−3 Ω−1), and excellent thermal stability at an annealing temperature of 300 oC owing to the good morphology maintenance of the Ag NWs covered by FTO thin films.

F-76 선박용 디젤유와 JP-8 항공유의 연소과정에서 발생되는 입자상물질(PM)의 무차원 광소멸계수를 Transmission Cell를 이용하여 측정하였다. 무차원 광소멸계수의 측정방식은 각각 광원의 파장길이가 633 nm와 853 nm인 대역에서 중력식 필터법에 의해 채집된 PM의 농도와 광학적 방법에 의해 측정된 PM의 농도를 비교하는 방법을 통해 이루어졌다. 광원의 파장길이, 633 nm 대역에서 측정된 무차원 광소멸계수는 F-76의 연료에서 발생된 PM의 경우 8.8인 반면 JP-8 연로부터 생성된 PM의 경우 9.8이였다. 한편 광원 파장길이가 853 nm로 증가함에 따라 두 연료 모두에서 발생된 PM의 무차원 광소멸계수는 각각 8.2 (F-76)와 8.8 (JP-8)로 감소하는 경향을 나타내었다.

The effect of titanium dioxide (TiO2) on the properties of color conversion glasses was examined for glasses based on BaO-ZnO-B2O3-SiO2. One glass sample, containing 25 mol% of each component, was used as a reference; the other three glass samples contained 1, 3, and 5 mol% TiO2, respectively. The four color conversion glass samples were prepared by sintering a mixture of glass frits and a YAG:Ce+ phosphor. The characteristics of the color conversion glass samples, such as luminous efficacy, luminance, CIE (Commission International de I'Eclairage) chromaticity, CCT (Correlated Color Temperature), and CRI (Color Rendering Index) were analyzed according to the PL spectrum. The refractive index of the glass samples was found to increase with the titanium dioxide content. In conclusion, luminous efficacy of color conversion glasses increased as the content of TiO2 was raised in the glass matrix.