• Title/Summary/Keyword: GeSe

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Measurement on the deep levels of $Cd_4GeSe_6$ single crystals ($Cd_4GeSe_6$ 단결정의 deep level측정)

  • 김덕태
    • Electrical & Electronic Materials
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    • v.7 no.6
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    • pp.504-510
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    • 1994
  • In this work the crystal structure, optical absorption and photoluminescence of Cd$_{4}$GeSe$_{6}$ single srystals grown by the vertical bridgman method are investigated. From the observed results of the PICTS, we proposed on energy band model which contains deep levels between the conduction band and the valence band. The energy band model permit us to explain the mechanism of the radiative recombination for the Cd$_{4}$GeSe$_{6}$ single crystals.als.

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Holographic Properties in Amorphous As-Ge-Se-S with Ag Thickness (Ag의 두께에 따른 비정질 As-Ge-Se-S의 홀로그래픽 특성연구)

  • Kim, Chung-Hyeok
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.25 no.3
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    • pp.213-217
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    • 2012
  • In this study, we have investigated the holographic grating formation on Ag-doped amorphous As-Ge-Se-S thin films. The dependence of diffraction efficiency as afunction of Ag layer thickness has been investigated in this amorphous chalcogenide films. Holographic gratings was formed using [P:P] polarized Diode Pumped Solid State laser (DPSS, 532.0 nm). The diffraction efficiency was obtained by +1st order intensity. The results were shown that the diffraction efficiency of Ag/AsGeSeS double layer thin films for the Ag thickness, the maximum grating diffraction efficiency using 60 nm Ag layer is 0.96%.

Holographic grating formation of $MgF_2$/As-Ge-Se-S multi-layer ($MgF_2$/As-Ge-Se-S 다층 박막에서의 홀로그래픽 격자 형성)

  • Na, Sun-Woong;Yeo, Cheol-Ho;Park, Jung-Il;Lee, Young-Jong;Chung, Hong-Bay
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07b
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    • pp.1042-1045
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    • 2002
  • We have carried out two-beam interference experiments to form holographic gratings on amorphous $MgF_2$/As-Ge-Se-S multi-layer. In this study, holographic gratings have been formed using He-Ne laser(632.8nm). under different polarization combinations. The diffraction efficiency was obtained by +1st order intensity. The maximum diffraction efficiency of As-Ge-Se-S single layer and $MgF_2$/As-Ge-Se-S multi-layer were 0.8% and 1.4%

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A Study of Phase-change Properties of Sb-doped Ag/Ge-Se-Te thin films (Sb-doped Ag/Ge-Se-Te 박막의 상변화 특성 연구)

  • Nam, Ki-Hyun;Jeong, Won-Kook;Park, Ju-Hyun;Chung, Hong-Bay
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.347-347
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    • 2010
  • In other to progress better crystallization transition and long phase-transformation data of phase-change memory (PRAM), we investigated about the effect of Sb doping and Ag ions percolating into Ge-Se-Te phase-change material. Doped Sb concentrations was determined each of 10 wt%, 20 wt% and 30 wt%. As the Sb-doping concentration was increased, the resistivity decreased and the crystallization temperature increased. Ionization of Ag was progressed by DPSS laser (532 nm) for 1 hour. The resistivity was more decreased and the crystallization temperature was more increased in case of adding Ag layer under Sb-(Ge-Se-Te) thin film. At the every condition of thin films included Ag layer more stable states were indicated compare with just Sb-doped Ge-Se-Te thin films.

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Characteristics of the photoinduced anisotropy(PA) in Ag/AsGeSeS multilayer thin films (Ag/AsGeSeS 다층박막의 광유기 이방성(PA) 특성)

  • Park, Jong-Hwa;Na, Sun-Woong;Yeo, Cheol-Ho;Park, Jeong-Il;Lee, Young-Jong;Chung, Hong-Bay
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11b
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    • pp.362-365
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    • 2001
  • The chalcogenide glasses of thin films have the superior property of photoinduced anisotrophy(PA). In this study, we observed the linear dichroism(D) using the irradiation with polarized He-Ne laser light, in the $Ag/As_{40}Ge_{10}Se_{15}S_{35}$ multi-layer. Mutilayer structures formed by alternating metal(Ag) a chalcogenide$(As_{40}Ge_{10}Se_{15}S_{35})$. Such multilayer structures have a greater sensitivity to illumination am larger dichroism in comparison the conventional double layer structure. Also new phenomena are discovered. These results will be show a capability of new method that suggested more improvement of photoinduced anisotropy property.

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Optical Properties of Zn4GeSe6:Co2+ Single Crystals (Zn4GeSe6:Co2+ 단결정의 광학적 특성)

  • 김형곤;김남오;최영일;김덕태;김창주
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.4
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    • pp.272-279
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    • 2003
  • In this work Zn$_4$GeSe$_{6}$ :CO$^{2+}$ single crystals were grown by the chemical transport reaction method in which the iodine was used as the transporting agent. The Zn$_4$GeSe$_{6}$ :CO$^{2+}$ single crystal was found to have a monoclinic structure. The optical absorption spectra of grown crystals were investigated using a temperature-controlled UV-VIS -NIR spectrophotometer. The temperature dependence of band-edge absorption was in a good agreement with the Varshni equation. The observed impurity absorption peaks could be explained as arising from the electron transition between energy levels of Co$^{2+}$ ion sited at the T$_{d}$ symmetry point.

Characteristics of the photoinduced anisotropy(PA) in Ag/AsGeSeS multilayer thin films (Ag/AsGeSeS 다층박막의 광유기 이방성(PA) 특성)

  • 박종화;나선웅;여철호;박정일;이영종;정홍배
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11a
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    • pp.362-365
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    • 2001
  • The chalcogenide glasses of thin films have the superior property of photoinduced anisotrophy(PA). In this study, we observed the linear dichroism(D) using the irradiation with polarized He-Ne laser light, in the Ag/As$\sub$40/Ge$\sub$10/Se$\sub$15/S$\sub$35/ multi-layer. Mutilayer structures farmed by alternating metal(Ag) a chalcogenide(As$\sub$40/Ge$\sub$10/Se$\sub$15/S$\sub$35/). Such multilayer structures have a greater sensitivity to illumination and larger dichroism in comparison the conventional double layer structure. Also new phenomena are discovered. These results will be show a capability of new method that suggested more improvement of photoinduced anisotropy property.

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The characteristic study of amorphous chalcogenide As-Ge-Se-S thin film for photonic crystal application (포토닉 크리스탈 응용을 위한 비정질 칼코게나이드 As-Ge-Se-S 박막의 특성 연구)

  • Nam, Ki-Hyeon;Ju, Long-Yun;Choi, Hyuk;Chung, Hong-Bay
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.11a
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    • pp.77-78
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    • 2007
  • In this paper, we suppose that the 1-dimensional photonic crystal using holography lithography. We used Ag doped amorphous AsGeSeS which belongs in the chalcogenide materials have sensitive photoluminescence property. The purpose of this experiment is the process to complete 3-D photonic crystal after making 2-D photonic crystal. The lattice formation was made an observation by irradiating He-Ne laser with the AsGeSeS film leaned obliquely. Then, by measuring formed diffraction beam, the diffraction lattice was calculated.

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The study on the cystallization and electrical properties of Ge-Se-Bi system chalcogenide glasses (Ge-Se-Bi chalcogenide glass의 비정질 및 결정화에 따른 전기전도도의 변화)

  • 이명원;강원호;박창만;이기암
    • Electrical & Electronic Materials
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    • v.6 no.2
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    • pp.175-183
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    • 1993
  • Amorphous Semicondyctor로서 Chalcogenide계의 Ge-Se-Bi계 비정질화와 결정화 실험을 통하여 전기전도도를 평가코자 하였다. 시료의 조성범위는 G $e_{15-25}$S $e_{65-85}$B $i_{2.5-15B}$의 범위에서 5N의 Ge, Se, Bi metal분말을 사용하였다. 시료는 석영관에 진공 장입후 용융시켜 비정질화 하였다. 이때 열처리 조건은 1000.deg.C에서 10시간 동안 가열하였으며 급냉 조건은 3834.deg.C/sec로 처리하였다. 비정질 sample의 결정화는 결정핵을 형성 시킨 후 온도 변화 및 시간의 변화를 주면서 결정을 성장시켰으며 이때 B $i_{2}$S $e_{3}$와 GeS $e_{2}$ 결정상을 관찰 할 수 있었다. 박막화는 위의 실험에 사용된 Bulk sample을 사용하여 박막을 제작하였으며 유리화 영역은 Ge 15 at%, Se 70 at% 이상, Bi가 10 at% 이하일 때 비정질화가 용이하였다. Bulk의 경우 Ge를 20 at%로 고정시 Bi의 at% 함량이 증가함에 따라 전기전도도가 증가했으며 Bi가 7.5 at%이상일때 급격한 전도도의 증가를 가져왔다. 박막의 경우엔 Bulk sample보다 Bi의 함량이 증가시 더욱 큰 전도도의 증가를 가져왔다. G $e_{20}$S $e_{77.5}$B $i_{2.5}$ 저성의 결정화 경우 330.deg.C에서 4hr 유지시킨 경우가 가장 양호하였다.다.하였다.다.

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The optical characteristics of amorphous $Se_{75}Ge_{25}$ thin film by the low-energy lon beam exposure (저 에너지 이온빔 조사에 따른 비정질 $Se_{75}Ge_{25}$ 박막의 광학적 특성)

  • 이현용;오연한;정홍배
    • Electrical & Electronic Materials
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    • v.7 no.2
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    • pp.100-106
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    • 1994
  • A bilayer film consisting of a layer of a-Se$_{75}$ Ge$_{25}$ with a surface layer of silver -100[.angs.] thick and a monolayer film of a-Se$_{75}$ Ge$_{25}$ are irradiated with 9[keV] Ga$^{+}$ ion beam. The Ga$^{+}$ ion (10$^{16}$ [ions/cm$^{2}$] exposed a-Se$_{75}$ Ge$_{25}$ and Ag/a-Se$_{75}$ Ge$_{25}$ thin films show an increase in optical absorption, and the absorption edge on irradiation with shifts toward longer wavelength. The shift toward longer wavelength called a "darkening effect" is observed also in film exposure to optical radiation(4.5*10$^{20}$ [photons/cm$^{2}$]). The 0.3[eV] edge shift for ion irradiation films is about twice to that obtained on irradiation with photons. These large changes are primarily due to structural changes, which lead to high etch selectivity and high sensitivity.

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