• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.19-22
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• 2009

A non-vacuum process for fabrication of $CuIn_xGa_{1-x}Se_2$ (CIGS) absorber layer from the corresponing Cu, In, Ga solution precursors was described. Cu, In, Ga precursor solution was prepared by a room temperature colloidal route by reacting the starting materials $Cu(NO_3)_2$, $InCl_3$, $Ga(NO_3)$ and methanol. The Cu, In, Ga precursor solution was mixed with ethylcellulose as organic binder material for the rheology of the mixture to be adjusted for the doctor blade method. After depositing the mixture of Cu, In, Ga solution with binder on Mo/glass substrate, the samples were preheated on the hot plate in air to evaporate remaining solvents and to burn the organic binder material. Subsequently, the resultant CIG/Mo/glass sample was selenized in Se evaporation in order to get a solar cell applicable dense CIGS absorber layer. The CIGS absorber layer selenized at $530^{\circ}C$ substrate temperature for 1h with various metal organic ratio.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.222-224
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• 2006

A non-vacuum process for $Cu(In,Ga)Se_2$ (CIGS) thin film solar cells from nanoparticle precursors was described in this work CIGS nanoparticle precursors was prepared by a low temperature colloidal route by reacting the starting materials $(CuI,\;InI_3,\;GaI_3\;and\;Na_2Se)$ in organic solvents, by which fine CIGS nanoparticles of about 20nm in diameter were obtained. The nanoparticle precursors were mixed with organic binder material for the rheology of the mixture to be adjusted for the doctor blade method. After depositing the mixture of CIGS with binder on Mo/glass substrate, the samples were preheated on the hot plate in air to evaporate remaining solvents ud to burn the organic binder material. Subsequently, the resultant (porous) CIGS/Mo/glass simple was selenized in a two-zone Rapid Thermal Process (RTP) furnace in order to get a solar ceil applicable dense CIGS absorber layer. Complete solar cell structure was obtained by depositing. The other layers including CdS buffer layer, ZnO window layer and Al electrodes by conventional methods. The resultant solar cell showed a conversion efficiency of 0.5%.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.3
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• pp.232-239
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• 2013

Thin light-active layers of the $CuInSe_2$ solar cell were prepared on Mo-coated sodalime glass substrates by one-step electrodeposition and post-annealing. The structure, morphology, and composition of $CuInSe_2$ film could be controlled by deposition parameters, such as the composition of metallic precursors, the concentration of complexing agents, and the temperature of post-annealing with elemental selenium. A dense and uniform Cu-poor $CuInSe_2$ film was successfully obtained in a range of parametric variation of electrodeposition with a constant voltage of -0.5 V vs. a Ag/AgCl reference electrode. The post-annealing of the film at high temperature above $500^{\circ}C$ induced crystallization of $CuInSe_2$ with well-developed grains. The KCN-treatment of the annealed $CuInSe_2$ films further induced Cu-poor $CuInSe_2$ films without secondary phases, such as $Cu_2Se$. The structure, morphology, and composition of $CuInSe_2$ films were compared with respect to the conditions of electrodeposition and post-annealing using SEM, XRD, Raman, AES and EDS analysis. And the conditions for preparing device-quality $CuInSe_2$ films by electrodeposition were proposed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.191-192
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• 2008

For phase transition method, good record sensitivity, low heat radiation, fast crystallization and hi-resolution are essential. Also, a retention time is very important part for phase-transition. In our past papers, we chose composition of $Ge_1Se_1Te_2$ material to use a Se factor which has good optical sensitivity than conventional Sb. Ge-Se-Te and Ag/$Ge_1Se_1Te_2$ samples are fabricated and irradiated with He-Ne laser and DPSS laser to investigate a reversible phase change by light. Because of Ag ions, the Ag layer inserted sample showed better performance than conventional one. We should note that this novel one showed another possibility for phase-change random access memory.

• Bulletin of the Korean Chemical Society
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• v.15 no.7
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• pp.545-549
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• 1994

Using the extended Hackel molecular orbital method in connection with the tight binding model, we have studied electronic structure and related properties of the charged cluster models relating to superconducting $YBa_{2}Cu_{3}O_{7-x}$, crystals in which O-atoms in regular sites were selectively replaced with Se atoms. In analogy to the isomorphism problem with molecules, we discuss all possible combinations of Se-substitutions in O-sites with one, two, and four Se atoms. The calculations are carried out within charged cluster models for analogues of YBa-copper oxide. Our results suggest that the electronic structure of the symmetrically Se-substituted or Se-added compound is closer to that of the YBCO superconducting compound than that obtained from the unsymmetrical substitution. This applies in particular if O is replaced with Se around the Cu(1) site. Symmetrical substitutions in the $CuO_2$ layers give rise to large variations in the electronic structure of $YBa_{2}Cu_{3}O_{7}$. This is consistent with the fact that superconductivity is very sensitive to the electronic population of the $CuO_2$ layers.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.375-375
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• 2011

Cu(In1-xGax)Se2 (CIGS)박막증착법 중 금속 전구체의 셀렌화 공정법은 다른 제조 방법에 비해 대면적 생산에 유리하고, 비교적 공정 과정이 간단하다는 장점이 있다. 이 제조 방법은 금속 전구체를 만든 후에 셀렌화 공정을 하게 된다. 셀렌화 공정은 대부분 H2Se 가스를 사용하지만 유독성으로 사용하는데 주의해야 한다. 본 실험은 H2Se를 사용하지 않고 Se원료를 주입하기 위해 Se cracker를 사용했고 금속 전구체 증착과 셀렌화를 동시에 하는 반응성 스퍼터링 후 열처리 법을 이용하여 CIGS 박막을 증착 했다. CIGS의 박막의 Cu/[In+Ga], Ga/[In+Ga]비를 변화시켜 특성변화를 관찰했다. Cu/[In+Ga]비가 감소할수록 CIGS의 결정방향인 (112) 이 우세하게 발달했고 Ga/[In+Ga]비가 증가할수록 CIGS의 결정면 사이의 값이 작아지기 때문에 CIGS peak의 2-Theta 값이 증가하게 된다. CIGS 박막 태양전지의 구조는 Al/Ni/ITO/i-ZnO/CdS/CIGS/Mo/glass 제작했다. CIGS박막의 조성비가 Cu/[In+Ga]=0.84, Ga/[In+Ga]=0.24인 박막태양전지에서 개방전압 0.48 V, 단락전류밀도 33.54 mA/cm2, 충실도 54.20% 그리고 변환효율 8.63%를 얻었다.

• Journal of the Korean Chemical Society
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• v.33 no.5
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• pp.477-477
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• 1989

The rates of the reaction of $[MoO_2(S_2CNEt_2)_2]$ with triphenylphosphine in 1,2-dichloroethane have been determined by the spectrophotometric method. The increase in the initial absorbance has been interpreted as a result of the production of $[Mo_2O_3(S_2CNEt_2)_4]$ and the decrease in absorbance then corresponds to the reduction of $[M_2O_3(S_2CNEt_2)_4]$. The data suggest mechanisms involving the enzymatic reaction in the first stage and the decay of intermediate, ${\mu}$-oxo molybdenum (V) dimer in the second stage.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.367-367
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• 2011

태양전지에서 광흡수층으로 널리 쓰이는 CuInSe2은 전기적, 광학적 특성이 우수하고 20%대의 고효율을 기록하며 큰 관심을 받고 있다. 하지만 증발법 및 스퍼터링 등의 기존 진공, 고온 기반 공정 기술은 원천적인 공정비용 절감이 어렵고, 고가의 희귀원소인 In 등의 원료 활용도가 떨어져 실험실 수준에 머무르고 있다. 최근 공정 비용을 최소화와 원료 활용을 극대화를 통해 고효율 CIGS 박막형 태양전지를 제조하기 위해 비진공 방식의 전구체 박막 코팅 및 열처리를 통한 광흡수층 제조에 관한 연구가 활발히 진행되고 있으며, 본 연구는 doctor-blade coating을 이용하여 전구체 박막을 기판 위에 형성하고 열처리 온도에 따른 박막 물성 변화를 관찰함으로써 박막 형성 메커니즘을 밝히는데 주력하였다. 또한 합성된 박막의 전기적, 광학적 특성을 분석하여 태양전지 응용 가능성을 살펴보았다. 본 연구에서는 SEM, XRD, TGA 분석을 통해 Cu, In, Se 전구체들이 각각 binary phase, 즉, Cu2-xSe 및 In2Se3의 metal chalcogenide을 형성하고, 고온에서 서로 결합하여 CuInSe2로 결정화 되는 현상을 관찰하였다. 또한 합성된 CIS 박막은 근적외선 및 가시광 영역에서 높은 광흡수도를 보였으며, 전기적으로 Mo 전극과 ohmic contact을 이룸으로써 CIGS계 태양전지의 광흡수층으로의 적합성을 나타내었다.

• Current Photovoltaic Research
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• v.3 no.3
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• pp.97-100
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• 2015

The kesterite $Cu_2ZnSnSe_4$ (CZTSe) thin film solar cells were synthesized by selenization of sputtered Cu/Sn/Zn metallic precursors on Mo coated soda lime glass substrate in Ar atmosphere. Cu/Sn/Zn metallic precursors were deposited by DC magnetron sputtering process with 30 W power at room temperature. As-deposited metallic precursors were placed in a graphite box with Se pellets and selenized using rapid thermal processing furnace at various temperature ($480^{\circ}C{\sim}560^{\circ}C$) without using a toxic $H_2Se$ gas. Effects of Selenization temperature on the morphological, crystallinity, electrical properties and cell efficiency were investigated by field emission scanning electron microscope (FE-SEM) and X-ray diffraction (XRD), J-V measurement system and solar simulator. Further details about effects of selenization temperature on CZTSe thin films will be discussed.

• Solar Energy
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• v.20 no.2
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• pp.43-54
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• 2000

We prepared and characterized $Cu(In_{1-x}Ga_x)Se_2$(CIGS) films using a elemental co-evaporation method for absorbing layer of high efficiency thin film solar cells. The CIGS films deposited on a soda-lime glass exhibited low resistivity because of higher carrier concentration. Na was accumulated at the CIGS surface and the 0 and Se were also accumulated at the surface, suggesting that oxidation is a driving force of Na accumulation. The structure of CIGS film was modified or a secondary phase was formed in the Cu-poor CIGS bulk films probably due to the incorporation of Na into Cu vacancy sites. As the Ga/(In+Ga) ratio increased, the diffraction peaks of $Cu(In_{1-x}Ga_x)Se_2$ films were shifted to larger angle and splitted, and the grain size of $Cu_{0.91}(In_{1-x}Ga_x)Se_2$ films became smaller. All $Cu_{0.91}(In_{1-x}Ga_x)Se_2$ films showed the p-type conductivity regardless of the Ga/(In+Ga) ratio. Ag/n-ZnO/i-ZnO/CdS/$Cu_{0.91}(In_{0.7}Ga_{0.3})Se_2$/Mo solar cells were fabricated. The currently best efficiency in this study was 14.48% for $0.18cm^2$ area ($V_{oc}=581.5mV,\;J_{sc}=34.88mA$, F.F=0.714).