• Title/Summary/Keyword: solar uv

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Transparent Conductors for Photoelectric Devices

  • Kim, Joondong;Patel, Malkeshkumar;Kim, Hong-Sik;Yun, Ju-Hyung;Kim, Hyunki
    • Proceedings of the Korean Vacuum Society Conference
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    • 2015.08a
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    • pp.87.2-87.2
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    • 2015
  • Transparent conductors are commonly used in photoelectric devices, where the electric energy converts to light energy or vice versa. Energy consumption devices, such as LEDs, Displays, Lighting devices use the electrical energy to generate light by carrier recombination. Meanwhile, solar cell is the only device to generate electric energy from the incident photon. Most photoelectric devices require a transparent electrode to pass the light in or out from a device. Beyond the passive role, transparent conductors can be employed to form Schottky junction or heterojunction to establish a rectifying current flow. Transparent conductor-embedded heterojunction device provides significant advantages of transparent electrode formation, no need for intentional doping process, and enhanced light-reactive surface area. Herein, we present versatile applications of transparent conductors, such as NiO, ZnO, ITO in photoelectric devices of solar cells and photodetectors for high-performing UV or IR detection. Moreover, we also introduce the growth of transparent ITO nanowires by sputtering methods for large scale application.

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Observation and Analysis of Radiation Characteristics According to the Type of City During the Summer Season - Focus on the Daegu Metropolitan City and the Surrounding Four Regions - (하절기 도시 유형별 복사특성 관측과 분석 -대구광역시와 인근 4개 지역을 중심으로-)

  • Choi, Dong-Ho;Lee, Bu-Yong;Jeong, Hyeong-Se
    • Journal of the Korean Solar Energy Society
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    • v.35 no.2
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    • pp.21-31
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    • 2015
  • The purpose of this study is to understand the characteristics of urban climate in several cities, from observing radiation according to wavelength band(UV, short and long wave radiation). Observation start from 5 May to 31 August 2013. The followings are the main results from this study. 1) In every observation area, greater amounts of short-wave radiation have been recorded in May compared to June. Even though the highest solar elevation occurs in June, May sees clearer days, which has attributed to the outcome. 2) The analysis concerning the correlation between ultraviolet radiation and shortwave radiation have revealed that regions closer to the Daegu area have stronger correspondence. 3) The time series of daily long-wave radiation shares a similar tendency with the time series of air temperature, and the maximum value was recorded at 14:00 and 15:00.

Measurements of Transmittances and Calculations of Fundamental Radiative Properties (투과율의 측정 및 이를 이용한 복사물성치의 계산)

  • Hwang, Yong-Ha;Park, Seung-Ho;Lee, Young-Soo
    • Solar Energy
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    • v.14 no.2
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    • pp.29-37
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    • 1994
  • Radiative charaacteristics of glass windows and porous absorbing media which can be used for a solar air heater are determined through the measurements of spectral transmittances. Those in the visible range are measured by the UV-IR spectrometer. Refractive index of glass are obtained by the comparison of the measured transmittances and the correlations derived from the electromagnetic theory and are compared to the theoretical ones calculated from the classical dispersion theory. Absorption and back-scattering coefficients of 15-mesh stainless wire screens are calcuated by the comparison of the measured transmittances and the correlations derived from the two flux model.

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The effect and stability of plant extract ingredient as uv absorber (자외선 흡수제로서의 식물추출성분의 안정성과 효과)

  • 김경동;이용두;박성순;윤성화;이석현
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.26 no.1
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    • pp.41-58
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    • 2000
  • Recently the harmfulness of W radiation is in creasing due to encironmental pollution. Environmental population may also play a role in global decrease of ozone layer, A major consequence of ozone depletion is increase in solar ultra violet radiation received at the earth's surface excessive exposure to W radiation cause a lot of problems in our skin. Plant extract that possess antioxidative activities has been reported to retard the oxidation process in product to which they have been added. Plant are alived under solar light. So it is expect the plants have so many protection mechanisms and UV absorbent ingredients against ultra violet radiation such as UVB, UVA. Plant extract which were flavonoids, alkaloids and others could be transformed into UV absorber by chemical modification. Therefore with the aim of finding alternative natural absorber that can safely be used in cosmetic, we have screened various extract for their UV absorbent effect. Thus, the cosmetic safety against human skin, antimicrobial effects and others could be improved by using the silicon.

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Synthesis and Photovoltaic Properties of Conducting Polymers Based on Phenothiazine (Phenothiazine계 전도성고분자의 합성 및 유기박막태양전지로의 적용 연구)

  • Yoo, Han-Sol;Park, Yong-Sung
    • Applied Chemistry for Engineering
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    • v.24 no.1
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    • pp.93-98
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    • 2013
  • In this paper, four conducting polymers (poly[(N-butyl-phenothiazine)-sulfide] (PBPS), poly[(N-hexyl-phenothiazine)-sulfide] (PHPS), poly[(N-decyl-phenothiazine)-sulfide] (PDPS), and poly[(N-(2-ethylhexyl)-phenothiazine)-sulfide] (PEHPS)) were synthesized with a high temperature and high pressure reaction. The structures of synthesized polymers were confirmed by $^1H-NMR$ and characterized by UV-Vis, cyclic voltammetry, and GPC. From the UV-Vis absorption spectra, the ${\lambda}_{max}$ values of PBPS, PHPS, PDPS, and PEHPS were 338, 341, 340, and 334 nm, respectively and their optical band gaps were 3.11, 3.13, 3.16, and 3.05 eV, respectively. To evaluate the feasible applicability as a photovoltaic cell, the devices composed of for example, ITO/PEDOT : PSS/polymer (PBPS, PDPS) : $PC_{71}BM$ (1 : 3, w/w)/$BaF_2$/Ba/Al were fabricated using the blends of the PBPS and PDPS as a donor, and $PC_{71}BM$ as an acceptor. Then, the power conversion efficiencies (PCE) of devices were estimated as 0.076% of PBPS and 0.136% of PDPS by solar simulator.

Out-of-Band Measurement of LED-based Solar Blind UV Filters

  • Cui, Muhan;Zhou, Yue;Chen, Xue;Yan, Feng;Zhang, Mingchao;Yang, Huaijiang
    • Journal of the Optical Society of Korea
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    • v.18 no.3
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    • pp.244-250
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    • 2014
  • Due to the difficulty in measuring very low out-of-band cutoff depths of solar blind UV filters, we propose a cutoff depth adjustable measurement system (CDAM) to test deep cutoff filters with a large dynamic range. The CDAM utilizing the substitution method is elaborately composed of several parts, including narrow-band LED light sources, standard reflective neutral attenuators with known attenuation coefficients, and a photomultiplier (PMT). This paper also presents an attenuator combination method ensuring that the PMT works within its linear response range. In addition, numerical simulation testifies to the method, and experiment shows that the CDAM system can achieve an extension of dynamic range from 0-6 OD to 0-10 OD, which is sufficient for the measurement of out-of-band cutoff depths of solar blind UV filters. Above all, the CDAM system, being easily implemented, of wide dynamic range, and highly precise, could be widely used in the measurement of filter cutoff depth.

VARIATIONS OF THE SOLAR FLARE ENERGY SPECTRUM OVER TWO ACTIVITY CYCLES (1972 - 1995)

  • KASINSKY V. V.;SOTNIKOVA R. T.
    • Journal of The Korean Astronomical Society
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    • v.29 no.spc1
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    • pp.315-316
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    • 1996
  • Based on X-ray (1-8 ${\AA}$) flux data for 1972-1995 the integral spectra of solar flare energy were computed. It has been shown that the spectral index $\beta$ of the integral energy spectrum (IES) vanes systematically with the 11-year cycle phase. The interval of $\beta$-variations (0.47 <$\beta$<1) is characteristic of UV-Cet stars. The maximum energy of the X-ray flares does not exceed $10^{32}$ erg.

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Synthesis and Characterization of New Push-Pull Chromophores Containing BF2-Azopyrrole Derivatives

  • Ko, HayeMin
    • Journal of the Korean Chemical Society
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    • v.60 no.1
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    • pp.21-27
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    • 2016
  • Novel push-pull chromophores containing 5’-(4-(bis(9,9-dimethyl-9H-fluoren-2-yl)aniline (bisDMFA) as a donor and phenylazo-methylpyrrolyl-boron difluoride (PhAPy-BF2) as an acceptor were designed and synthesized by the Knoevenagel condensation reaction for organic solar cells. Various electron withdrawing moieties were effectively introduced using 2,4-dimethyl-1H-pyrrole to afford new asymmetric BF2-azopyrrole molecules that were characterized by UV-vis spectroscopy and cyclic voltammetry measurements.