• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.386-386
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• 2009

TCO/p/i/n 구조의 비정질 실리콘 박막 태양전지의 제작에 있어서 TCO계면과 p층사이의 이종접합에서의 큰 밴드갭 차이는 p층으로부터의 정공 재결합을 통하여 효율 저하의 원인이 된다. 이러한 재결합은 넓은 밴드갭을 가진 물질을 완충층으로 삽입함으로써 개선되어 질 수 있다. 본 논문에서는 비정질 실리콘 보다 넓은 광학적 밴드갭을 가지는 a-SiOx 박막을 완충층으로 사용하여 TCO/P 계면에서의 재결합 감소에 대한 시뮬레이션을 수행하였다. a-SiOX 박막 내에 포함된 산소의 양에 따라 밴드갭을 조절하여 1.8eV~2.0eV 사이의 완충층을 삽입하여 박막태양전지의 개방전압, 단락전류, 효율 등에 끼치는 영향을 ASA 시뮬레이션을 통하여 알아보았다.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.218-218
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• 2011

The CIGS Solar Cells have the highest conversion efficiency in the film-type solar cells. They consist of p-type CuInSe2 film and n-type ZnO film. The CdS films are used as buffer layer in the CIGS solar cells since remarkable difference in the lattice constant and energy band gap of two films. The CdS films are toxic and make harmful circumstances. The CdS films deposition process need wet process. In this works, we design and make the hitter and lamp reflection part in the sputtering system for the ZnS films deposition as buffer layer, not using wet process. Film thickness, SEM, and AFM are measured for the uniformity valuation of the ZnS films. We conclude the optimum deposition temperature for the films uniformity less than 1.6%. The ZnS films deposited by the sputtering system are more dense and uniform than the CdS films deposited by the Chemical Bath Deposition Method(CBD) for the CIGS Solar Cells.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.206-206
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• 2011

투명 전도성 산화물 (TCO, Transparent Conductive Oxide) 박막을 태양전지에 적용하기 위해서는 우수한 전기 전도성 및 가시광 영역에서 높은 투과율을 가져야 한다. 대표적인 TCO 물질인 ITO (Indium tin oxide) 박막은 우수한 전기적, 광학적 특성을 가지고 있지만 $400^{\circ}C$ 이상의 고온에서는 전기저항이 급격히 증가하게 되어 실제 태양전지 패널에 적용했을 때 전기적 특성이 저하된다. 따라서 태양전지용 TCO 박막을 개발 시, 뛰어난 고온 안정성이 요구되고 있다. 본 연구에서는 고온 안정적 특성을 지니는 Ga3+를 도핑한 ZnO 계열 TCO인 GZO/ITO multi-layered 박막을 증착하였다. 또한 buffer layer의 두께 변화 및 구조 제어를 통한 최위층 박막의 전기적 특성 및 결정성을 조사하였으며 다층 박막의 계면 간 특성 및 굴절률 제어를 통한 광학적 물성을 연구하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1557-1559
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• 2009

By using optimum doping ratio (10 ~ 20 wt%) of glycerol, the power conversion efficiency (PCE) of organic photovoltaic devices based on poly (3-hexylthiophene) and phenyl-$C_{61}$-butyric acid methyl ester was dramatically increased from 3.23% to 5.03%. Finally, semitransparent organic photovoltaic devices including glycerol doped poly (3,4-ethylenedioxy-thiophene):poly (styrene sulfonate) and thin Ag (< 1 nm) buffer layer typically have shown PCE > 3% with transmittance > 30% in visible ranges.

• Journal of the Korean institute of surface engineering
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• v.52 no.6
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• pp.289-292
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• 2019

Transparent and conducting titanium doped indium oxide (TIO) thin films were deposited by RF magnetron sputtering on zinc oxide (ZnO)-coated glass substrates to investigate the effect of the ZnO buffer layer on optical and electrical properties of TIO/ZnO bi-layered films. TIO 90 nm / ZnO 10 nm films having a lower resistivity (3.09×10^-3 Ωcm) and a higher visible transmittance (80.3%) than other TIO/ZnO films were prepared in this study. Figure of merit results indicate that a 10 nm thick ZnO thin film is an effective buffer layer that enhances optical transmittance and electrical conductivity of TIO films without intentional substrate heating or post-deposition annealing.

• Journal of the Korean Ceramic Society
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• v.43 no.6 s.289
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• pp.369-375
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• 2006

[ $(Ba_{0.5}Sr_{0.5})_{0.99}Co_{x}Fe_{1-x}O_{3-{\delta}}$ ] [x=0.8, 0.2](BSCF) powders were synthesized by a Glycine-Nitrate Process (GNP) and the electrochemical performance of the BSCF cathode on a scandia stabilized zirconia, $[(Sc_{2}O_3)_{0.11}(ZrO_2)_{0.89}]-1Al_{2}O_3$ was investigated. In order to prevent unfavorable solid-state reactions between the cathode and zirconia electrolyte, a GDC ($Gd_{0.1}Ce_{0.9}O_{2-{delta}}$) buffer layer was applied on ScSZ. The BSCF (x = 0.8) cathode formed on GDC(Buffer)/ScSZ(Disk) showed poor electrochemical property, because the BSCF cathode layer peeled off after the heat-treatment. On the other hand, there were no delamination or peel off between the BSCF and GDC buffer layer, and the BSCF (x = 0.2) cathode exhibited fairly good electrochemical performances. It was considered that the observed phenomenon was associated with the thermal expansion mismatch between the cathode and buffer layer. The ohmic resistance of the double layer cathode was slightly lower than that of the single layer BSCF cathode due to the incorporation of platinum particle into the BSCF second layer.

• Journal of the Korean Vacuum Society
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• v.5 no.3
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• pp.258-262
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• 1996

We have investigated the changes in magnetoresistive characteristics, interfacial roughness, and preferred orientation with the Fe buffer layer thickness, annealing temperature, and the stacking number of layers variation in Fe/[NiFe/Cu] multilayers by using the 3-gun d.c. magnetron sputtering method. Intensity of the (200) orientation was increased with the increment of the Fe-buffer layer thickness. We found a maximum magnetoresistance ration of 4.7%, when the buffer layer thickness was 70$\AA$, and the field sensitivity also showed a maximum value at the same thickness. We varied the stacking number of multilayers with fixing the Fe buffer layer thickness of 70$\AA$. When the stacking number was 40 layers, maximum MR ratio(5.3%) was observed. With the variation of annealing temperature no change in the MR ratio was found beyond $300^{\circ}C$. But decrement of MR ratio was observed above $300^{\circ}C$. This decrement of the MR ratio was responsible for the increment of paramagnetic mixed layer caused by the diffusion of Cu layer and the change of antiferromagnetic coupling.

• Proceedings of the Materials Research Society of Korea Conference
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• 2010.05a
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• pp.35.1-35.1
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• 2010

The Cu(In,Ga)Se2(CIGS) thin film solar cells have been achieved until almost 20% efficiency by NREL. These solar cells include chemically deposited CdS as buffer layer between CIGS absorber layer and ZnO window layer. Although CIGS solar cells with CdS buffer layer show excellent performance, many groups made hard efforts to overcome its disadvantages in terms of high absorption of short wavelength, Cd hazardous element. Among Cd-free candidate materials, the CIGS thin film solar cells with Zn compound buffer layer seem to be promising with 15.2%(module by showa shell K.K.), 18.6%(small area by NREL). However, few groups were successful to report high-efficiency CIGS solar cells with Zn compound buffer layer, compared to be known how to fabricate these solar cells. Each group's chemical bah deposition (CBD) condition is seriously different. It may mean that it is not fully understood to grow high quality Zn compound thin film on the CIGS using CBD. In this study, we focused to clarify growth mechanism of chemically deposited Zn compound thin film on the CIGS, especially. Additionally, we tried to characterize junction properties with unfavorable issues, that is, slow growth rate, imperfect film coverage and minimize these issues. Early works reported that film deposition rate increased with reagent concentration and film covered whole rough CIGS surface. But they did not mention well how film growth of zinc compound evolves homogeneously or heterogeneously and what kinds of defects exist within film that can cause low solar performance. We observed sufficient correlation between growth quality and concentration of NH3 as complex agent. When NH3 concentration increased, thickness of zinc compound increased with dominant heterogeneous growth for high quality film. But the large amounts of NH3 in the solution made many particles of zinc hydroxide due to hydroxide ions. The zinc hydroxides bonded weakly to the CIGS surface have been removed at rinsing after CBD.

• Current Photovoltaic Research
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• v.9 no.3
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• pp.96-105
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• 2021

Even though above 22% efficiencies have been reported in Cd-free Cu(In,Ga)Se₂ (CIGS) solar cell with Zn-containing buffers, the efficiencies with Zn-containing buffers, in general, are well below 20%. One of the reasons is Zn diffusion from the Zn-containing buffer layer to CIGS film during buffer growth. To avoid the degradation, it is necessary to prevent the diffusion of Zn atoms from Zn-containing buffer to CIGS film. For the purpose, we characterized an In₂Se₃ film as a possible diffusion barrier layer because In₂Se₃ has no Zn component. It was found that an In₂Se₃ layer grown at 300℃ was very effective in preventing Zn diffusion from a Zn-containing buffer. Also, the In₂Se₃ had a large potential barrier in the valence band at the In₂Se₃/CIGS interface. Therefore, In₂Se₃ passivation has the potential to achieve a super-high efficiency in CIGS solar cells that employ Cd-free ALD processed buffers containing Zn.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.6
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• pp.493-498
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• 2008

This Paper describes the Raman scattering characteristics of polycrystalline (Poly) 3C-SiC thin films, in which they were deposited on AlN buffer layer by APCVD using hexamethyldisilane (MHDS) and carrier gases (Ar+$H_2$). When the Raman spectra of SiC films deposited on the AlN layer of before and after annealing were worked according to growth temperature, D and G bands of graphite were measured. It can be explained that poly 3C-SiC films admixe with nanoparticle graphite and its C/Si rate is higher than ($C/Si\;{\approx}\;3$) that of the conventional SiC, which has no D and G bands related to graphite. From the Raman shifts of 3C-SiC films deposited at $1180^{\circ}C$ on the AlN layer of after annealing, the biaxial stress of poly 3C-SiC films was obtained as 896 MPa.