• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.3
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• pp.188-194
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• 1998

The GaSe:$Er^{3+}$(5mol%) single crystals grown by the Bridgman technique displayed a direct energy gap at 1.79 eV and an indirect energy gap of 1.62 eV at 300 ${\circ}^$K. Also an optical absorption peak by impurity was found at 6505 $cm^{-1}$. The peak identified the origin of the electronic transitions to be between the energy levels of $Er^{3+}$ ions.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.159-160
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• 2006

$AgGaSe_2$ single crystal thin films grown by using hot wall epitaxy (HWE) system. The single crystal thin films were investigated by photoluminescence and double crystal X-ray diffraction(DCXD) measurement. From the photoluminescence measurement of $AgGaSe_2$ single crystal thin film, we observed free excition ($E_x$) observable only in high quality crystal and neutral bound exciton ($D^{\circ}$,X) having very strong peak intensity. And, the full width at hall maximum and binding energy of neutral donor bound excition were 8 meV and 14.1 meV, respectively. By Haynes rule, an activation energy of impurity was 141 meV.

• Journal of the Korean Institute of Telematics and Electronics
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• v.23 no.5
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• pp.706-711
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• 1986

The AgGa1-xInxSe2 films are deposited by a flash evaporation method onto pyrex glass substrates at temperatures between 5\ulcorner and 360\ulcorner. The single crystalline films which have X-ray diffraction peak of only (112) plane are preared at substrate temperature above 360\ulcorner. The prepared AgGa 1-xInxSe2 films are high photosensitive. The temperature coefficients of energy gap are found to be (-1.2~-4.0)x10**4 eV/K and (-3.1~-5.2)x10**-4 eV/K, and that of peak energy of spectral photoresponse curve are found to be (-1.1 ~ -3.0)x10**-4 eV/K(50K~100K) and (-2.4~-5.1)x10**-4 eV/K(100K~300K).

• Prospectives of Industrial Chemistry
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• v.20 no.2
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• pp.1-12
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• 2017

Cu(In,Ga)Se₂ (CIGS)계 박막 태양전지 기술은 1970년대 처음으로 소개된 이래 지속적인 기술적 진보를 이루어 왔으며, 저가·고안정성·고효율이라는 다양한 장점으로 태양광 시장에서 성공적인 안착을 노리고 있다. 이 논문은 CIGS 박막 태양전지의 개발 이력 및 요소 기술에 대해서 살펴보고 국가별 연구·개발 활동에 대해서 약술하였다. 아울러, 앞으로의 사회·시장에 변화에 대응한 연구 개발 방향에서 대해서도 논하였다.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.20 no.3
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• pp.107-112
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• 2010

The Cu$(In_{1-x}Ga_x)Se_2$ is the absorber material for thin film solar cell with high absorption coefficient of $1{\times}10^5cm^{-1}$. In the case of CIGS, the movable energy band gap from $CuInSe_2$ (1.00 eV) to $CuGaSe_2$ (1.68 eV) can be acquired while controlling Ga contain ratio. Generally, the co-evaporator method have used for development and fabrication of the CIGS absorption layer. However, this method should need many steps and lengthy deposition time with high temperature. For these reasons, in this paper, a new growth method of CIGS layer was attempted to hydride vapor transport (HVT) method. The CIGS mixed-source material reacted for HCl gas in the source zone was deposited on the substrate after transporting to growth zone. c-plane $Al_2O_3$ and undoped GaN were used as substrates for growth. The characteristics of grown samples were measured from SEM and EDS.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.21 no.3
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• pp.99-104
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• 2011

A stoichiometric mixture of evaporating materials for $MgGa_2Se_4$ single crystal thin films was prepared from horizontal electric furnace. The crystal structure of these compounds has a rhombohedral structure with lattice constants $a_0=3.953\;{\AA}$, $c_0=38.890\;{\AA}$. To obtain the single crystal thin films, $MgGa_2Se_4$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperatures were $610^{\circ}C$ and $400^{\circ}C$, respectively. The crystalline structure of the single crystal thin films was investigated by the double crystal X-ray rocking curve and X-ray diffraction ${\omega}-2{\theta}$ scans. The carrier density and mobility of $MgGa_2Se_4$ single crystal thin films measured from Hall effect by van der Pauw method were $6.21{\times}10^{18}\;cm^{-3}$ and 248 $cm^2/v{\cdot}s$ at 293 K, respectively. The optical absorption of $MgGa_2Se_4$ single crystal thin films was investigated in the temperature range from 10 K to 293 K. The temperature dependence of the optical energy gap of the $MgGa_2Se_4$ obtained from the absorption spectra was well described by the Varshni's equation, $E_g(T)=E_g(0)-({\alpha}T^2/T+{\beta})$. The constants of Varshni's equation had the values of $E_g(0)=2.34\;eV$, ${\alpha}=8.81{\times}10^{-4}\;eV/K$ and ${\beta}=251\;K$, respectively.

• Korean Journal of Materials Research
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• v.7 no.10
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• pp.914-918
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• 1997

MBS에 의해(001)GaAs기판 위에 성장된 Zn$_{1-x}$Co$_{x}$Se(x=1.0, 7.4, 9.5 %)반도체 박막과 (ZnSe/FeSe)반도체 초격자 박막의 미세구조를 투과전자현미경을 이용하여 연구하였다. Zn$_{1-x}$Co$_{x}$Se 박막 시편의 경우, 박막과 기판 사이의 격자 불일치때문에 a/2<110>형태의 버거즈 벡터를 가지는 부정합 전위를 관찰하였다. 모든 Zn$_{1-x}$Co$_{x}$Se 박막과 기판의 계면은 뚜렷이 구별되었고, 계면에서 산화물이나 이물질이 존재하지 않았다. 또한, (ZnSe/FeSe)초격자를 성장시키기 전에 GaAs기판 위에 ZnSe바닥층을 넣음으로써 고품질의 (ZnSe/FeSe)초격자를 얻었다. (ZnSe/FeSe)초격자에 있는 FeSe는 섬아연광 결정구조로 존재하였다.

• Current Photovoltaic Research
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• v.5 no.4
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• pp.135-139
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• 2017

We fabricated two different transparent conducting oxide thin films of ZnO doped with Ga ($Ga_2O_3$ 0.9 wt%) as well as Al ($Al_2O_3$ 2.1 wt%) (GAZO) and ZnO doped only with Al ($Al_2O_3$ 3 wt%) (AZO). It was investigated how it affects the moisture resistance of the transparent electrode. In addition, $Cu(In,Ga)Se_2$ thin film solar cells with two transparent oxides as front electrodes were fabricated, and the correlation between humidity resistance of transparent electrodes and device performance of solar cells was examined. When both transparent electrodes were exposed to high temperature distilled water, they showed a rapid increase in sheet resistance and a decrease in the fill factor of the solar cell. However, AZO showed a drastic decrease in efficiency at the beginning of exposure, while GAZO showed that the deterioration of efficiency occurred over a long period of time and that the long term moisture resistance of GAZO was better.

• Proceedings of the Materials Research Society of Korea Conference
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• 2002.05a
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• pp.73-73
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• 2002

• Proceedings of the Materials Research Society of Korea Conference
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• 2007.11a
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• pp.57.1-57.1
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• 2007