• Transactions on Electrical and Electronic Materials
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• 제12권3호
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• pp.123-126
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• 2011

Titanium dioxide ($TiO_2$) thin films were deposited by the sol-gel method with a surfactant-assisted mechanism. Its application for dye-sensitized solar cells (DSSCs) was investigated. Brunauer-Emmett-Teller, X-ray diffraction and field emission scanning electron microscopy techniques were used to characterize the surface characteristics of thin films. Photovoltaic-current density measurements were performed to determine the photoelectrochemical properties of the thin films and the performance of DSSCs. Energy conversion efficiency of about 6.1% was achieved for cells with conductive glass under illumination with AM 1.5 (100 $mWcm^{-2}$) simulated sunlight. Investigation showed higher photo-energy conversion efficiency for mesoporous $TiO_2$ nanocrystalline films used in DSSCs relative to commercially available Degussa P25 films.

• Korean Chemical Engineering Research
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• 제58권1호
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• pp.1-20
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• 2020

화석 연료를 이용하는 에너지원이 심각한 환경오염을 일으키고, 인류의 건강한 삶에 큰 영향을 주어 청정한 에너지 자원의 개발은 매우 중요한 이슈가 되었다. 화석 연료를 대체하기 위한 다양한 에너지원의 개발이 진행되고 있으며, 그 중 최근에는 태양 전지에 대한 관심이 점차 커지고 있다. 현재 실용화 되어 있는 태양전지는 실리콘 기반 태양전지인데, 제조비용이 큰 단점이 부각되고 있으며 이에 따라 이의 단점을 개선하기 위한 노력과 동시에 실리콘 기반 태양전지를 대체하려는 시도가 이루어지고 있다. 이중 실리콘 기반 태양전지를 대체할 후보로 페로브스카이트 태양전지가 큰 관심을 받고 있는데, 그 이유는 높은 광전 변환 효율, 저렴한 제조비용, 유연한 형태로의 제조 가능성 때문이다. 그러나 현재 보고되고 있는 페로브스카이트 태양전지는 장기적 안정성이 떨어지며, 또 납으로 인해 신체에 유해하다는 큰 단점을 가지고 있다. 본 리뷰에서는 페로브스카이트 태양전지의 장기적 안정성을 높이는 방안들 그리고 환경적으로 유해한 납을 사용하지 않는 방안들의 최신 연구 방향 동향에 관하여 살펴보았다.

• 전기전자학회논문지
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• 제23권4호
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• pp.1448-1456
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• 2019

본 연구에서는 작물재배용 단동식 유리온실 내에 LED 광원을 적용할 때, LED의 전원 공급을 위한 태양전지를 에너지 저감과 광투과율을 고려하여 Si 계열의 태양전지와 염료감응형 태양전지(DSSC)를 유리온실에 선별적 배치하고, 작물 재배에 유효한 태양전지의 광투과율을 결정하기 위해 유리온실의 천정과 측면에 대해 광투과율 변화에 따른 조도 시뮬레이션을 수행하였다. 또한, 유리온실에서 주광과 인공광인 LED 광원을 모두 고려하는 경우 최적 조명제어에 따른 유리온실의 에너지 절감 효과를 분석하였다.

• 한국재료학회지
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• 제24권9호
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• pp.502-507
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• 2014

Recently, improvement in the conversion efficiency of silicon-based solar cells has been achieved by decreasing emitter doping concentration, because the lightly doped emitter can effectively prevent the recombination of electrons and holes generated by solar light irradiation. This type of emitter is very thin due to the low doping concentration, thus conductive materials (i.e., silver) used for front electrodes can easily penetrate the emitter during a firing process because of their large diffusivity in silicon. This results in junction leakage currents which might reduce cell efficiencies. In this study, $Al_2O_3$-coated Ag powders were synthesized by an ultrasonic spray pyrolysis method and applied to the conductive materials of the front electrode to control the junction leakage current. The $Al_2O_3$ shell obstructs the Ag diffusion into the emitter during the firing process. The powder is spherical with a core-shell structure and the thickness of the $Al_2O_3$ shell is tens of nanometers. Solar cells were fabricated using pure Ag powders or the $Al_2O_3$-coated Ag powder as front electrode materials, and the conversion efficiency and junction leakage current were compared to investigate the role of the $Al_2O_3$ shell during the firing processes.

• Current Photovoltaic Research
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• 제9권4호
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• pp.111-122
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• 2021

Silicon heterojunction technology (HJT) solar cells have received considerable attention due to advantages that include high efficiency over 26%, good performance in the real world environment, and easy application to bifacial power generation using symmetric device structure. Furthermore, ultra-highly efficient perovskite/c-Si tandem devices using the HJT bottom cells have been reported. In this paper, we discuss the unique feature of the HJT solar cells, the fabrication processes and the current status of technology development. We also investigate practical challenges and key technologies of the HJT solar cell manufacturers for reducing fabrication cost and increasing productivity.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.318.2-318.2
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• 2014

The high contact resistance is still one of the major issues to be resolved in CdS/CdTe thin film solar cells. CdTe/Metal Schottky contact induced a high contact resistance in CdS/CdTe solar cells. It has been reported that the work function of CdTe thin film is more than 5.7 eV. There has not been a suitable back contact metal, because CdTe thin film has a high work function. In a few decades, some buffer layer was reported to improve a back contact problem. Buffer layers which are Te, $Sb_2Te_3$, $Cu_2Te$, ZnTe:Cu and so on was inserted between CdTe and metal electrode. A formed buffer layers made a tunnel junction. Hole carriers which was excited in CdTe film by light absorption was transported from CdTe to back metal electrode. In this report, we reported the variation of solar cell performance with different buffer layer at the back contact of CdTe thin film solar cell.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2014년도 추계학술대회 논문집
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• pp.221-221
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• 2014

The current energy crisis in many countries has led to the search of an efficient renewable energy source. Among those the solar energy is the most abundant and easily available. However harvesting the solar energy requires a much efficient device. Lot of research has been done in this regard and so far the efficiency of traditional solar cell stands around ~50% and for PET films it is much lesser. The potential application of PET films in the solar cells can be very promising provided the fact that the PET film is lighter and logistically more viable. There is a lot of work that is being done to increase the efficiency of PET based solar cells. The base electrode plays a vital role in increasing the efficiency of the cell.

• Current Photovoltaic Research
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• 제10권1호
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• pp.23-27
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• 2022

In this study, we investigate organic-inorganic halide perovskite solar cells with a vacuum thermal evaporated hole transporting layer (NPB/MoO_3-x). By replacing solution process based Spiro-MeOTAD with vacuum thermal evaporation based NPB/MoO_3-x, a thin hole transporting layer was implemented. In addition, parasitic absorption that may occur during the doping process was eliminated by excluding solution process doping. In a solar cell with a thin vacuum thermal evaporated hole transporting layer, the short-circuit current density (Jsc) increased to 23.93 mA/cm², resulting in the highest power converstion efficiency (PCE) at 18.76%. Considering these results, it is essential to control the thickness of hole transporting layer located at the top in solar cell configuration.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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• pp.109-109
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• 2006

Screen printing (SP) metal contact is typically applied to the solar cells for mass production. However, SP metal contact has low aspect ratio, low accuracy, hard control of the substrate penetration and unclean process. On the other hand, photo lithograpy (PL) metal contact can reduce defects by metal contact. In this investigation, PL metal contact was obtained the multi-layer structure of Ti/Pd/Ag by e-beam process. We applied SP metal contact and PL metal contact to single crystalline silicon solar cells, and demonstrated the difference of conversion efficiency. Because PL metal contact silicon solar cell has Jsc (short circuit current density) better than silicon solar cell applied SP metal contact.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.444-445
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• 2009

The metallic contact system of silicon solar cell must have several properties, such as low contact resistance, easy application and good adhesion. Ni is shown to be a suitable barrier to Cu diffusion as well as desirable contact metal to silicon. Nickel monosilicide(NiSi) has been suggested as a suitable silicide due to its lower resistivity, lower sintering temperature and lower layer stress than $TiSi_2$. Copper and Silver can be plated by electro & light-induced plating method. Light-induced plating makes use the photovoltaic effect of solar cell to deposit the metal on the front contact. The cell is immersed into the electrolytic plating bath and irradiated at the front side by light source, which leads to a current density in the front side grid. Electroless plated Ni/ Electro&light-induced plated Cu/ Light-induced plated Ag contact solar cells result in an energy conversion efficiency of 16.446 % on $0.2\sim0.6\;{\Omega}{\cdot}cm$, $20\;\times\;20\;mm^2$, CZ(Czochralski) wafer.