• 제목/요약/키워드: Electronic absorption

검색결과 905건 처리시간 0.03초

Broadband Light Absorption Using Gap Plasmon Resonance

  • Ko, Hyungduk;Kim, Jung Hyuk;Lim, Ju Won;Lee, Gi Yong;Jang, Ho Seong;Ko, Doo-Hyun;Han, Il Ki
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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    • pp.133.2-133.2
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    • 2014
  • A gap surface plasmon resonator have received considerable attention because it can dramatically enhance the absorption of the electromagnetic field. However, whereas most of studies were just focused on the absorption within a narrow range of wavelength, few studies have been performed for the broadband absorption in the visible range. Therefore, in this study, we discuss methods that can induce broadband light absorption using gap plasmon resonance in visible regime. The gap plasmon resonator will offer great potential for appplications to solar cells and bioimaging.

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Size Dependent Absorption Spectrum of ZnO Nanocrystals

  • Chang Ho Jung;Wang Yongsheng;Suh Kwang-Jong;Son Chang-Sik
    • 한국재료학회지
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    • 제15권7호
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    • pp.431-434
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    • 2005
  • To investigate the dependences of the absorption spectrum and electronic structure properties on the ZnO nano-particle size, ZnO nanocrystals were synthesized by a sol-gel method. The absorption onset peak exhibits a systematic blue-shift with decreasing particle size due to the quantum confinement effect, as well as, with decreasing $Zn^{2+}$ concentration. The increase of particle size is mainly controlled by coarsening and aggregation step during the nucleation and growth of ZnO nano-particles. The onset absorption spectrum of ZnO colloids changes from 310 to 355 nm as $Zn^{2+}$ concentration increases from 0.01 to 0.1 mole. The average particle size as a function of aging- time can be determined from the absorption spectra. The freshly prepared nanocrystal size was about 2.8nm.

Performance improvement of countercurrent-flow membrane gas absorption in a hollow fiber gas-liquid membrane contactor

  • Ho, Chii-Dong;Sung, Yun-Jen;Chen, Wei-Ting;Tsai, Feng-Chi
    • Membrane and Water Treatment
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    • 제8권1호
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    • pp.35-50
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    • 2017
  • The theoretical membrane gas absorption module treatments in a hollow fiber gas-liquid membrane contactor using Happel's free surface model were obtained under countercurrent-flow operations. The analytical solutions were obtained using the separated variable method with an orthogonal expansion technique extended in power series. The $CO_2$ concentration in the liquid absorbent, total absorption rate and absorption efficiency were calculated theoretically and experimentally with the liquid absorbent flow rate, gas feed flow rate and initial $CO_2$ concentration in the gas feed as parameters. The improvements in device performance under countercurrent-flow operations to increase the absorption efficiency in a carbon dioxide and nitrogen gas feed mixture using a pure water liquid absorbent were achieved and compared with those in the concurrent-flow operation. Both good qualitative and quantitative agreements were achieved between the experimental results and theoretical predictions for countercurrent flow in a hollow fiber gas-liquid membrane contactor with accuracy of $6.62{\times}10^{-2}{\leq}E{\leq}8.98{\times}10^{-2}$.

캐스팅법으로 제작한 Poly(3-hexylthiophene)의 흡수스펙트럼에 따른 형광 특성 (Characteristics of Electronic Absorption Spectrum and Photoluminescence in Cast-Poly(3-hexylthiophene) Films)

  • 김주승;구할본;조재철
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1998년도 추계학술대회 논문집
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    • pp.57-60
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    • 1998
  • Poly(3-hexylthiophene)(P3HT) was synthesized by use of FeCl$_3$ as a oxidizing agent at $25^{\circ}C$. The infrared spectrum of our polymer gave good evidence for the conjugation of 3-hexylthiophene monomer unit. P3HT contains the HT(head-to-tail) linkage larger than 64% based on NMR analysis. Electronic absorption and photoluminescence studies show that cast films of P3HT have three exciting state. Absorption spectrum was separated with three maximum peaks by Giese-French method and shifted to the shorter wavelength with increasing temperature. Separated absorption spectrum of P3HT is well adapted to PL peak appeared at longer wavelength. Low temperature PL spectrum is well separated at 669nm, 733nm and 812nm.

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Measurement of Absorption Coefficient for Quantum Confined Stark Effect In GaAsP/In P MQW Na Refractive Index Change

  • Song, Ju-Bin;Killey, R.
    • Journal of the Optical Society of Korea
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    • 제5권4호
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    • pp.123-130
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    • 2001
  • In this paper, we report measurement of absorption coefficient for various InGaAs MQW QCSE device structures. The absorption spectra over a range of QCSE were obtained from measured photocurrent spectra. The refractive index changes with applied electric field were calculated from the absorption spectra.

진단용 X-ray 영역에서 조영제의 흡수단에 관한 연구 (The Study on the Absorption edge for Contrast Media in the Region of Diagnostic X-ray)

  • 김영근;이경섭
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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    • pp.330-332
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    • 1997
  • The absorption coefficient of contrast media was measured region of diagnostic X-ray. Relative values of absorption coefficient was found the largest peak in the range of $60{\sim}70kVp$ for sodium sulfate and 60kVp for iodine. Increasing the thickness of contrast media and patient, the values of absorption coefficient was rising.

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$HgGa_2S_4:CO^{2+}$ 단결정의 불순물 광흡수 (Impurity optical absorption of $HgGa_2S_4:CO^{2+}$ single crystals)

  • 김형곤;김남오;김병철;최영일;김덕태;현승철;방태환;이경섭;구할본
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 춘계학술대회 논문집
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    • pp.3-7
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    • 2004
  • $HgGa_2S_4:CO^{2+}$ single crystal were grown by the chemical transport reaction(CTR) method. 1n the optical absorption spectrum of the $HgGa_2S_4:CO^{2+}$ single crystal measured at 298K, three groups of impurity optical absorption peaks consisting of three peaks, respectively, were observed at 673nm, 734nm, and 760nm, 1621nm, 1654nm, and 1734nm, and 2544nm, 2650nm, and 2678nm. At 10K, the three peaks(673nm, 734nm, and 760nm) of the first group were split to be twelve peaks. These impurity optical absorption peaks are assigned to be due to the electronic transitions between the split energy levels of $Co^{2+}$ sited in the $S_4$ symmetry point.

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고전 자동역학 방법을 사용한 실리콘 표면위의 이온화된 Al의 물리기상증착에 관한 연구 (Classical Molecular Dynamics Study of Al lonized Physical Vapor Deposition on Silicon Surface)

  • Kang, Jeong-Won;Lee, Young-Ghik;Mun, Won-Ha;Son, Myung-Sik;Hwang, Ho-Jung
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 1999년도 추계종합학술대회 논문집
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    • pp.895-898
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    • 1999
  • We calculated Al-Absorption, Al-reflection, and Si-etching probabilities as a function of incident angle and energy using classical molecular dynamics (MD) simulation. Variations of the cases of Al-absorption rate and Al-reflection rate are less than that of Si-etching rate. In contrast with general prediction, our simulation results showed that channeling of the <110> direction occurred the most in the case of incident angle between 30degree and 40degree. We investigated that channeling of the <110> directions quite affect Al-absorption rate in silicon. Since Si-etching rate is high and Al-absorption rate by <110> channeling is high, we found that Al ionized physical vapor deposition (PVD) on Si(001) has a different characteristics with Al ionized PVD on A1(111).

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Theoretical Studies on Electronic Structure and Absorption Spectrum of Prototypical Technetium-Diphosphonate Complex 99mTc-MDP

  • Qiu, Ling;Lin, Jian-Guo;Gong, Xue-Dong;Ju, Xue-Hai;Luo, Shi-Neng
    • Bulletin of the Korean Chemical Society
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    • 제32권7호
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    • pp.2358-2368
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    • 2011
  • Density functional theory (DFT) and time-dependent density functional theory (TDDFT) calculations, employing the B3LYP method and the LANL2DZ, 6-31G$^*$(LANL2DZ for Tc), 6-31G$^*$(cc-pVDZ-pp for Tc) and DGDZVP basis sets, have been performed to investigate the electronic structures and absorption spectra of the technetium-99m-labeled methylenediphosphonate ($^{99m}Tc$-MDP) complex of the simplest diphosphonate ligand. The bonding situations and natural bond orbital compositions were studied by the Mulliken population analysis (MPA) and natural bond orbital (NBO) analysis. The results indicate that the ${\sigma}$ and ${\pi}$ contributions to the Tc-O bonds are strongly polarized towards the oxygen atoms and the ionic contribution to the Tc-O bonding is larger than the covalent contribution. The electronic transitions investigated by TDDFT calculations and molecular orbital analyses show that the origin of all absorption bands is ascribed to the ligand-to-metal charge transfer (LMCT) character. The solvent effect on the electronic structures and absorption spectra has also been studied by performing DFT and TDDFT calculations at the B3LYP/6-31G$^*$(cc-pVDZ-pp for Tc) level with the integral equation formalism polarized continuum model (IEFPCM) in different media. It is found that the absorption spectra display blue shift in different extents with the increase of solvent polarity.

의용방사선 영역에서 조영제의 물성에 잔한 연구 (The Study on the Physical Properties for Contrast Media in 7be Region of Diagnostic Radiology)

  • 김영근;이경섭
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1997년도 추계학술대회 논문집
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    • pp.132-135
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    • 1997
  • The absorption coefficient of contrast media was meassured region of diagnostic radiology. Relative values of absorption coefficient was fecund the largest peak in the range of 60 ∼ 70kVp for sodium sulfate and 60kVp for iodine. Increasing the thickness of contrast media and patient the values of absorption coefficient was rising.

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