• Current Photovoltaic Research
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• v.9 no.4
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• pp.137-144
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• 2021

In this study, the microstructure of the CVD-fabricated Cu(In,Ga)Se₂ (CIGSe) absorber layer by simulating the stacking sequence used in a co-evaporation method, and changes solar cell performance were investigated. The absorber layer prepared by stacking CuSe and (In,Ga)Se between InSe is separated into Ga-free CuInSe₂ and Ga-rich CIGSe, and transformed to CIGSe by selenization heat treatment with slight improvement in the the solar cell efficiency. However, in CVD, since the supply of liquid Cu-Se is not as active as in the co-evaporation method, the nanoocrystalline layer containing a large amount of Ga remained independently in the absorption layer, which acted as a cause of the loss of J_SC and FF. Therefore, by using a precursor structure in which CuGa is sputter-deposited on a single layer of InSe deposited by CVD, performance parameters of V_OC, J_SC, and FF could be greatly improved.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.346-349
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• 2007

치밀한 $CuInSe_{2}$ (CIS) 태양전지용 광흡수층을 제조하기 위해 상용되는 출발물질을 이용하여 비진공방식인 paste coating 법으로 CIS 막을 제조하였다. 먼저 치밀한 CIS 막 제조를 위해 $Cu_{2}Se$의 액상 거동을 관찰하였다. 이러한 $Cu_{2}Se_{2}$의 액상거동을 위해 Se 분위기에서 Se 증발온도, 기판온도, 열처리시간 등을 다양하게 변화 시켰으며, Se 증발온도 $450^{\circ}C$, 기판온도 $550^{\circ}C$, 열처리시간 30분 그리고 수송가스 ($N_{2}$)를 20 sccm으로 최적조건을 형성하였다. 이러한 최적조건을 바탕으로 치밀한 CIS막을 위해 two-zone RIP (rapid temperature process) 방법으로 Se 분위기 안에서 셀렌화를 위한 열처리를 행하였다. 셀렌화를 위해 다양한 열처리시간에 따라 형성된 CIS 막은 CIS 광흡수층과 Mo 박막 사이에서 $MoSe_{2}$ 층이 형성되었지만, 균일한 CIS 막을 얻었으며 업자성장과 치밀화 거동을 관찰 하였다. 또한, CIS 막의 치밀화를 위해 Se 증발온도와 열처리시간을 고정하고 기판온도를 $600^{\circ}C$로 증가시켜 $Cu_{2}Se$의 액상거동을 관찰하였다. $600^{\circ}C$에서 형성된 CIS 막은 기판온도 $500^{\circ}C$의 시편보다 입자성장과 치밀화가 되었으나 기판으로 사용하는 soda-lime glass의 휨 현상이 발생하였다.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.2
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• pp.296-302
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• 1994

Polycrystalline CuInSeS12T thin were prepared by depositing Cu/In layer, which was sequentially sputtered varying the Cu/(Cu+In) mole ratio, on glass substrate and selenizing with selenium metal vapor in a nitrogen atmosphere. Compositional and structural, characterization was carried out by X-ray diffraction (XRD), wavelength-dispersive spectroscopy(WDS), and scanning electron microscope(SEM). Electrical characterization was carried out by the measurements of Hall effect, electrical resistivity. Large indium loss occurs in early stage of the selenization process. The selenized films which had mole ratios larger than 0.28 have chalcopyrite CuInSeS12T phase and these that had less mole ratios have sphalerite phase. The selenized films containing CuS1xTSe phase have Cu-rich CuInSeS12T phase and these that did not contain CuS1xTSe have In-rich CuInSeS12T phase. By optimizing the sputtering conditions,it is possible to fabricate CuInSeS12T thin films which have little secondary phases and an appropriate hole concentration (10S015T ~ 10S016TcmS0-3T) for solar cells.

• Bulletin of the Korean Chemical Society
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• v.32 no.12
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• pp.4332-4336
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• 2011

The chalcopyrite-type $CuInSe_2$ is a remarkable material for thin film solar cells owing to its electronic structure and optical response. Single-phase sphere-like $CuInSe_2$ nanocrystallite particles were prepared by a facile noninjection method with triethanolamine as the complexing agent and the solvent simultaneously. The period of the reaction was the key to form single-phase $CuInSe_2$ nanocrystals at $240^{\circ}C$. TEM, XRD, XPS, EDX investigations were performed to characterize the morphology and the detailed structure of as-synthesized $CuInSe_2$ nanocrystals. All of the analysis results proved that the synthesized nanocrystals were pure phase and close to the stoichiometric ratio rather than a simple mixture. The band gap of the obtained $CuInSe_2$ nanocrystals was $1.03{\pm}0.03$ eV.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1587-1589
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• 2002

Photovoltaics is considered as one of the most promising new energy technology, because its energy source is omni present, pollution-free and inexhaustive. It is agreed that these solar cells must be thin film type because thin film process is cost-efficive in the fact that it uses much less raw materials and can be continuous. The defect chalcopyrite material $CuIn_3Se_5$ has been identified as playing an essential role in efficient photovoltaic action in $CuInSe_2$-based devicesm It has been reported to be of n-type conductivity, forming a p-n junction with its p-type counterpart CuInSe2. Because the most efficient cells consist of the $Cu(In,Ga)Se_2$ quarternary, knowledge of some physical properties of the Ga-containing defect chalcopyrite $Cu(In,Ga)_3Se_5$ may help us better understand the junction phenomena in such devices.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.354-355
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• 2007

Process variables for manufacturing the $CuInSe_2$ thin film were established in order to clarify optimum conditions for growth of the thin film depending upon process conditions (substrate temperature, sputtering pressure, DC/RF Power), and then by changing a number of vapor deposition conditions and Annealing conditions variously, structural and electrical characteristics were measured. Thereby, optimum process variables were derived. For the manufacture of the $CuInSe_2$, Cu, In and Se were vapor-deposited in the named order. Among them, Cu and In were vapor-deposited by using the sputtering method in consideration of their adhesive force to the substrate, and the DC/RF power was controlled so that the composition of Cu and In might be 1 : 1, while the surface temperature having an effect on the quality of the thin film was changed from 100[$^{\circ}C$] to 300[$^{\circ}C$] at intervals of 50[$^{\circ}C$].

• Journal of the Korean institute of surface engineering
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• v.49 no.1
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• pp.40-45
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• 2016

Recently, $Bi_2Te_3$-based alloys are the best thermoelectric materials near to room temperature, so it has been researched to achieve increased figure of merit(ZT). Ternary compounds such as Bi-Te-Se and Bi-Sb-Te have higher thermoelectric property than binary compound Bi-Te and Sb-Te, respectively. Compared to DC plating method, pulsed electrodeposition is able to control parameters including average current density, and on/off pulse time etc. Thereby the morphology and properties of the films can be improved. In this study, we electrodeposited n-type ternary Cu-doped $Bi_2(Te-Se)_3$ thin film by modified pulse technique at room temperature. To further enhance thermoelectric properties of $Bi_2(Te-Se)_3$ thin film, we optimized Cu doping concentration in $Bi_2(Te-Se)_3$ thin film and correlated it to electrical and thermoelectric properties. Thus, the crystal, electrical, and thermoelectric properties of electrodeposited $Bi_2(Te-Se)_3$ thin film were characterized the XRD, SEM, EDS, Seebeck measurement, and Hall effect measurement, respectively. As a result, the thermoelectric properties of Cu-doped $Bi_2(Te-Se)_3$ thin films were observed that the Seebeck coefficient is $-101.2{\mu}V/K$ and the power factor is $1412.6{\mu}W/mK^2$ at 10 mg of Cu weight. The power factor of Cu-doped $Bi_2(Te-Se)_3$ thin film is 1.4 times higher than undoped $Bi_2(Te-Se)_3$ thin film.

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.566-569
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• 2006

태양전지는 태양광에너지를 바로 전기에너지로 전환시키는 소자이다. 과거에 많이 연구되던 고품질의 단결정 소자는 높은 에너지 변환효율을 가지고 있으나 가격 경쟁력이 크게 뒤져 일반화되지 못하였다. 최근에는 다결정 태양전지의 응웅 가능성에 대한 연구가 활발히 진행되어 오고 있다. 이중 $CuInSe_2$는 여러 가지 좋은 물성을 가지고 있어서, 저가의 고효율 태양전지를 위한 광흡수층 재료로 가장 주목받고 있다. $CuInSe_2$ 화합물 박막을 제조하기 위해 단위원소를 spttering법 과 Evaporeation법을 사용하여 증착하고 전기로에서 열처리 공정을 사용하여 single-phase 화합물 $CuInSe_2$ 박막을 얻고자 하였다.

• Bulletin of the Korean Chemical Society
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• v.35 no.8
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• pp.2331-2334
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• 2014

$Cu_2SnSe_3$ (CTSe) and $Cu_2ZnSnSe_4$ (CZTSe) nanoparticles were synthesized by sonochemical reactions under multibubble sonoluminescence (MBSL) conditions. First, $Cu_2SnSe_3$ nanoparticles were synthesized by the sonochemical method with an 85% yield, using CuCl, $SnCl_2$, and Se. Second, ZnSe was coated on the CTSe nanoparticles by the same method. Then, they were transformed into CZTSe nanoparticles of 5-7 nm diameters by heating them at $500^{\circ}C$ for 1 h. The ratios between Zn and Sn could be controlled from 1 to 3.75 by adjusting the relative concentrations of CTSe and ZnSe. With relatively lower Zn:Sn ratios (0.75-1.26), there are mostly CZTSe nanoparticles but they are believed to include very small amount of CTS and ZnSe particles. The prepared nanoparticles show different band gaps from 1.36 to 1.47 eV depending on the Zn/Sn ratios. In this sonochemical method without using any toxic or high temperature solvents, the specific stoichiometric element Zn/Sn ratios in CZTSe were controllable on demand and their experimental results were always reproducible in separate syntheses. The CZTSe nanoparticles were investigated by using X-ray diffractometer, a UV-Vis spectrophotometer, scanning electron microscope, Raman spectroscopy, and a high resolution-transmission electron microscope.

• Bulletin of the Korean Chemical Society
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• v.16 no.7
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• pp.588-591
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• 1995

Single crystals of (ZnSe)1-x(CuMSe2)x (M=Al, Ga, or In) were grown by chemical vapor transport technique. Powdered polycrystalline samples of (ZnSe)1-x(CuMSe2)x (M=Al, Ga, or In) were also prepared by the direct combination of the elements. The chemical composition of these single crystals was determined by comparing their lattice parameters with those of the standard polycrystalline samples. The IR transmission range of single crystals of (ZnSe)1-x(CuMSe2)x (M=Al, Ga, or In) is slightly narrower than that observed for pure ZnSe. However, these materials still show good transmission in the long-wavelength IR range. The addition of small amounts of CuMSe2 (M=Al, Ga, or In) considerably increases the hardness of ZnSe.