• Title/Summary/Keyword: CD spectroscopy

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A Study on $Ni_{0.8}Cd_{0.2}Fe_2O_4$ by Mossbauer spectroscopy (Mossbauer 분광법을 이용한 $Ni_{0.8}Cd_{0.2}Fe_2O_4$)

  • Baek, Seung-Do
    • Korean Journal of Materials Research
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    • v.6 no.11
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    • pp.1107-1112
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    • 1996
  • Ni를 Cd로 대치시켜 세라믹 소결법으로 합성한 Ni0.8Cd0.2Fe2O4 의 X-ray 회절선을 측정하여 구조를 확인하고, 형성된 결정체의 격자 상수를 조사하였다. 이 시료의 Mossbauer 스펙트럼을 80K-900K의 온도 영역에서 측정 분석하여 Mossbauer parameter의 온도 의존성과 Fe 이온에 대한 자료를 얻고, 이 자료를 토대로 Ni0.8Cd0.2Fe2O4 의 자기 전이 현상과 Curied 온도 Tc와 격자 비열 및 Debye 온도와 같은 물성을 조사하였다.

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$CdCl_2$ 활성화 공정과 후면 산화막 제거 공정을 거친 CdTe 박막의 표면 물성 변화 연구

  • Cheon, Seung-Ju;Lee, Seung-Hun;Jeong, Yeong-Hun;Bae, Jong-Seong;Kim, Ji-Hyeon;Kim, Dong-Hwan
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2012.05a
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    • pp.98.1-98.1
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    • 2012
  • CdS/CdTe 박막 태양전지의 경우 높은 광흡수 계수를 가지고 있는 CdTe 다결정 박막을 흡수층으로이용 한다. CdTe 다결정 박막의 경우 CdS/CdTe 계면과 박막 내부에 많은 결함들이 존재 하며, CdTe 박막 내부에 존재하는 캐리어의 수를 증가 시키기 위하여 $CdCl_2$ 활성화 공정을 거치게 된다. 이때 박막의 물성 변화를 분석 하기 위하여, X-Ray Diffractometer (XRD), X-ray Photoelectron Spectroscopy (XPS)를 이용하여 박막 표면 분석을 진행 하였다. 이를 통해 박막 표면에서 산소가 Cd와 Te과 결합하면서 산화막이 생성되는 것을 확인하였다. 박막 표면에 생성된 산화막은 후면 금속 전극 형성을 위해, 용액 공정을 통하여 제거 되는데, 이때 CdTe 박막 표면에서 Cd이 용액에 의해 제거 되는 것을 확인 하였다.

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Band Alignment at CdS/wide-band-gap Cu(In,Ga)Se2 Hetero-junction by using PES/IPES

  • Kong, Sok-Hyun;Kima, Kyung-Hwan
    • Transactions on Electrical and Electronic Materials
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    • v.6 no.5
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    • pp.229-232
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    • 2005
  • Direct characterization of band alignment at chemical bath deposition $(CBD)-CdS/Cu_{0.93}(In_{1-x}Ga_x)Se_2$ has been carried out by photoemission spectroscopy (PES) and inverse photoemission spectroscopy (IPES). Ar ion beam etching at the condition of the low ion kinetic energy of 400 eV yields a removal of surface contamination as well as successful development of intrinsic feature of each layer and the interfaces. Especially interior regions of the wide gap CIGS layers with a band gap of $1.4\~1.6\;eV$ were successfully exposed. IPES spectra revealed that conduction band offset (CBO) at the interface region over the wide gap CIGS of x = 0.60 and 0.75 was negative, where the conduction band minimum of CdS was lower than that of CIGS. It was also observed that an energy spacing between conduction band minimum (CBM) of CdS layer and valance band maximum (VBM) of $Cu_{0.93}(In_{0.25}Ga_{0.75})Se_2$ layer at interface region was no wider than that of the interface over the $Cu_{0.93}(In_{0.60}Ga_{0.40})Se_2$ layer.

Studies on the Cd(II)-Flavonoid Chelation Reactions (카드뮴(II)-플라보노이드 킬레이트 반응에 관한 연구)

  • Lee, Jeong-Ho;Shin, Sun-Woo;Baek, Seung-Hwa
    • YAKHAK HOEJI
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    • v.54 no.1
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    • pp.13-21
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    • 2010
  • The interaction of cadmium (II) ion with quercetin, qurecitrin and (+)-catechin was investigated in aqueous solution at various pH. The flavonoid/cadmium stochiometries for cadmium (II) binding to flavonoid have been determined by UV-visible spectroscopy. 1:1 Cd(II)-Flavonoid complex had a maximum absorbance and showed the bathochromic shift of the long-wavelength band of the UV-vis spectra in the alkaline pH, that occurs upon complexation, is due to a ligand-tometal charge transfer. The optimal concentration of Cd(II)-flavonoid complexes showed that complexation reaction could be classified in the following way: 55.27 ${\mu}M$ catechin > 54.72 ${\mu}M$ quercetin > 53.52 ${\mu}M$ quercitrin at the chelating site level. These results suggest that Cd(II)-flavonoid complex has the optimal condition of chelation in 0.2 M $NH_3$ - 0.2 M $NH_4Cl$ (pH 8.0) solution.

CdS Thin Films Properties Prepared by Chemical Bath Deposition Techniques for Photoresists

  • Gang, Go-Ru;Yun, Ju-Yeong;Kim, Jin-Tae;Cha, Deok-Jun
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.481-481
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    • 2013
  • Chemical bath deposition (CBD) 기술에 의해 slide glass 기판 위에 CdS 박막을 적층 형성하였다. 적층된 박막들은 CdCl2와 thiorea (H2NCSNH2)를 증류수와 혼합 시dipping의 온도 조건, pH 조건, 시간 및 횟수를 달리하여 균일한 표면이 형성되도록 하였다. 적층된 박막은 $200^{\circ}C$ 이상의 고온에서 annealing하여 결정화하였다. 적층한 박막은 결정화 요인들을 XRD, FE-SEM, AFM, EDX, UV-Vis spectroscopy를 통해 조사하였다. 형성된 박막은 포토레지스터로 활용될 가능성을 조사하였다.

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The Initial Stages of the Oxidation of the CdTe surfaces (CdTe 표면의 산화과정의 초기단계)

  • 김형도;오세정
    • Journal of the Korean Vacuum Society
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    • v.1 no.1
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    • pp.50-59
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    • 1992
  • By means of X-ray photoelectron spectroscopy(XPS), the initial stages of the oxidation of the cleaved CdTe (110) surface and the sputtered CdTe surface with oxygen exposure are invetigated. From the analyses of the spectra of Te 3dsn, Cd 3d5/2, 0 ls and Cd MNN Auger lines, it is shown that two oxygen atoms bond to one Te atom at the initial stages.

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Fabrication and Evaluation of Spectroscopic Grade Quasi-hemispherical CdZnTe Detector

  • Beomjun Park;Kyungeun Jung;Changsoo Kim
    • Journal of Radiation Protection and Research
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    • v.49 no.2
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    • pp.85-90
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    • 2024
  • Background: This study focuses on the fabrication and characterization of quasi-hemispherical Cd0.9Zn0.1Te (CZT) detector for gamma-ray spectroscopy applications, aiming to contribute to advancements in radiation measurement and research. Materials and Methods: A CZT ingot was grown using the vertical Bridgman technique, followed by proper fabrication processes including wafering, polishing, chemical etching, electrode deposition, and passivation. Response properties were evaluated under various external bias voltages using gamma-ray sources such as Co-57, Ba-133, and Cs-137. Results and Discussion: The fabricated quasi-hemispherical CZT detector demonstrated sufficient response properties across a wide range of gamma-ray energies, with sufficient energy resolution and peak distinguishability. Higher external bias voltages led to improved performance in terms of energy resolution and peak shape. However, further improvements in defect properties are necessary to enhance detector performance under low bias conditions. Conclusion: This study underscores the efficacy of quasi-hemispherical CZT detector for gamma-ray spectroscopy, providing valuable insights for enhancing their capabilities in radiation research field.

Complexation Studies for Cadmium (II) with Quercetin and (+)-Catechin (Quercetin과 (+)-Catechin의 카드뮴(II)에 대한 착물반응)

  • Lee, Jeong-Ho;Shin, Sun-Woo;Baek, Seung-Hwa
    • YAKHAK HOEJI
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    • v.53 no.6
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    • pp.342-350
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    • 2009
  • The interaction of cadmium (II) ion with quercetin and (+)-catechin was investigated in aqueous solution at various pH. The flavonoid/cadmium stochiometries for cadmium (II) binding to quercetin and (+)-catechin have been determined by UV-vis spectroscopy. 1 : 1 Cd (II)-Flavonoid complex had a maximum absorbance and showed the bathochromic shift of the long-wavelength band of the UV-vis spectra in the alkaline pH, that occurs upon complexation, due to a ligandto-metal charge transfer. These results suggest that Cd (II)-flavonoid complex has the optimal condition of chelation in 0.2 M $NH_3$ - 0.2 M $NH_4Cl$ (pH 8.0) solution.

Intensity-dependent dynamics of photoinduced absorption in CdS0.4/Se0.6 semiconductor doped glasses

  • Seo, Jung-Chul;Kim, Dong-Ho;Kong, Hong-Jin
    • Journal of the Optical Society of Korea
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    • v.1 no.1
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    • pp.15-18
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    • 1997
  • Intensity dependent dynamics of photoinduced absorption in $CdS_{0.4}$/$Se_{0.6}$ semiconductor doped glasses below the band gap was investigated by using time-resolved differential transmittance spectroscopy. The carriers populated through ultrafast trapping at semiconductor-glass interfaces give rise to a broad photoinduced absorption below the band gap. The decay time of transient absorption depends strongly on the excitation intensity. Based on our results, the physical mechanism for photoinduced absorption processes was suggested.