• Journal of the Korean institute of surface engineering
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• v.49 no.3
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• pp.301-306
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• 2016

The effects of nanotexturing and post-etching on the reflection and quantum efficiency properties of diamond wire sawn (DWS) multicrystalline silicon (mc-Si) solar cell have been investigated. The chemical solutions, which are acidic etching solution (HF-$HNO_3$), metal assisted chemical etching (MAC etch) solutions ($AgNO_3$-HF-DI, HF-$H_2O_2$-DI) and post-etching solution (diluted KOH at $80^{\circ}C$), were used for micro- and nano-texturing at the surface of diamond wire sawn (DWS) mc-Si wafer. Experiments were performed with various post-etching time conditions in order to determine the optimized etching condition for solar cell. The reflectance of mc-Si wafer texturing with acidic etching solution showed a very high reflectance value of about 30% (w/o anti-reflection coating), which indicates the insufficient light absorption for solar cell. The formation of nano-texture on the surface of mc-Si contributed to the enhancement of light absorption. Also, post-etching time condition of 240 s was found adequate to the nano-texturing of mc-Si due to its high external quantum efficiency of about 30% at short wavelengths and high short circuit current density ($J_{sc}$) of $35.4mA/cm^2$.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.378-381
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• 2008

고효율 a-Si:H/c-Si 이종접합 태양전지를 얻기 위해서는 우수한 c-Si wafer 위에 고품질의 비정질 실리콘박막을 통한 heterointerface를 형성하는 것이 매우 중요하다. 이를 달성하기 위해서는 공정중에 오염되기 쉬운 Si wafer 표면 상태를 정확히 검사하고 잘 관리하여야 한다. 본 연구에서는 세정 및 표면산화에 따른 Si wafer 상태를 Spectroscopic Ellipsometry 및 u-PCD를 이용하여 분석하였으며, <$\varepsilon$2> @4.25eV 값이 Si wafer 상태를 잘 나타내고 있음을 확인하였고 세정 최적화 할 경우 그 값이 43.02에 도달하였다. 또한 RF-PECVD로 증착된a-Si:H 박막을 EMA 모델링을 통해 분석한 결과 낮은 결정성과 높은 밀도를 가지는 a-Si:H를 얻을 수 있었으며, 이를 이종접합 태양전지에 적용한 결과 Flat wafer상에서 10.88%, textured wafer 적용하여 13.23%의 변환효율을 얻었다. 결론적으로 Spectroscopic Ellipsometry가 매우 얇고 고품질의 다층 박막이 필요한 이종접합 태양전지 분석에 있어 매우 유용한 방법임이 확인되었다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.419-420
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• 2009

The authors fabricated the nanostructural patterns on the surface of SiN antireflection layer of polycrystalline Si solar cell and the surface of crystalline Si wafer using anodic aluminum oxide (AAO) masks in an inductively coupled plasma(ICP) etching process. The AAO nanopattern mask has the hole size of about 70~80nm and an ave rage lattice constant of 100nm. The transferred nano-patterns were observed by the scanning electron microscope (SEM) and the enhancement of solar cell efficiency will be presented.

• Journal of the Korean Institute of Telematics and Electronics
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• v.21 no.1
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• pp.45-50
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• 1984

V-groove N+P solar cell is fabricated by thermal diffusion in silicon wafer with (100) crystal structure. To form the V-grooves in (100) silicon surface, a mixture of etylen-diamine, water, pyrocathecol is used as the etchant of anisotropic etching. Under light intensity of 100mW/$\textrm{cm}^2$, the efficiency of the V-groove solar cell is 2.5-3.5% greater than the conventional N+P solar cell and 0.4-0.6% greater than the texturized one.

• Journal of the Korean Solar Energy Society
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• v.33 no.5
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• pp.24-33
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• 2013

Renewable energy industries, including sola cell plants, has been ever increasing ones for reducing fossil fuel consumption and strengthening national energy policy. In this paper we tried to identify occupational health hazards in solar cell-related industries operated in Korea. Poly silicon, silicon ingot and wafer, solar cell and module are major processes for producing solar cells. Poly silicon operations may cause hazards to workers from metal silicon, silanes, silicon, hydro fluoric acid and nitric acid. Solar cells could not be constructed without using metals such as aluminum and silver, acids such as hydrofluoric acid and nitric acid, bases such as sodium hydroxide and potassium hydroxide, and solvent and phosphorus chloride oxide. Workers in module assembly process may exposed to isopropanol, flux, solders that contain lead, tin and/or copper. To prevent occupational exposure to these hazards, it is essential to identify the hazards in each process and educate workers in industries with proper engineering and administrative control measures.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.143-146
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• 2009

One of the most important issues of crystalline silicon solar cell is minimizing reflectance at the surface. Laser texturing is an isotropic process that will sculpt the surface of a silicon wafer, regardless of its crystallographic orientation. We investigated surface texturing process using Nd-YAG laser ($\lambda$=1064 nm) on multi-crystalline silicon wafer. Removal of slag formed after the laser process was performed using acid solution (HF : $HNO_3$ : $CH_3COOH$ : DI water). The reflectance and carrier lifetime of the samples were measured and analyzed using UV-Vis spectrophotometer and carrier lifetime tester. It was found that the minimum reflectance of the samples was 16.39% and maximum carrier life time was $21.8\;{\mu}s$.

• Journal of the Korean Vacuum Society
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• v.19 no.5
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• pp.391-396
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• 2010

The pn junction for solar cell was prepared on p-type Si wafer by the furnace using the $POCl_3$ and oxygen mixed precursor to research the characteristic of interface at pn junction. The sheet resistance was decreased in accordance with the increasing the diffusion process time for n-type doping on p-type Si wafer. The electron affinity at the interface in the pn junction was decreased with increasing the amount of n-type doping and the sheet resistance also decreased. Consequently, the drift current due to the generation of EHP increased because of low potential barrier. The efficiency and fill factor were increased at the solar cell with increasing the diffusion process time.

• Journal of the Korean institute of surface engineering
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• v.40 no.3
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• pp.138-143
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• 2007

The effects of texturing and anti-reflection coating on the reflection properties of multi-crystalline silicon solar cell have been investigated. The chemical solutions of alkaline and acidic etching solutions were used for texturing at the surface of multi-crystalline Si wafer. Experiments were performed with various temperature and time conditions in order to determine the optimized etching condition. Alkaline etching solution was found inadequate to the texturing of multi-crystalline Si due to its high reflectance of about 25%. The reflectance of Si wafer texturing with acidic etching solution showed a very low reflectance about 10%, which was attributed to the formation of homogeneous. Also, deposition of ITO anti-reflection coating reduced the reflectance of multi-crystalline si etched with acidic solution($HF+HNO_3$) to 2.6%.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.2
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• pp.144-150
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• 2013

A New Ag-pastes were developed for integrating the high efficiency mono-Si solar cell. The pastes were the mixture of 84 wt% Ag, 2 wt% glass frit, 11 wt% solvent of buthyl cabitol acetate, and 3 wt% additives. After fabricating the Ag-pastes by using a 3-roll mill, they were coated on a $SiN_x$/n+/p- stacks of a commercial mono-Si solar cell. And the post-thermal process was also optimized by varying the process conditions of peak temperature. The optimized solar cell efficiency on a 6-inch mono-Si wafer was 18.28%, which was the one of the world best performances. It meaned that the newly developed Ag-paste could be adopted to fabricate a commercial bulk Si solar cell.

• Current Photovoltaic Research
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• v.9 no.4
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• pp.123-127
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• 2021

This study was on electrode design for the realization of a solar cell that combines electrode formation and module integration process to overcome printing limitations. We used the passivated emitter rear contact (PERC) solar cell. Wafer size was 156.75 mm ×156.75 mm. The fabricated cell results showed that the open-circuit voltage of 649 mV, short-circuit current density of 36.15 mA/cm², fill factor of 68.5%, and efficiency of 16.06% with electrode conditions the 24BBs with the width 190 ㎛ and 90FBs with the width 45 ㎛. For improving efficiency, the characteristics of the solar cell were checked according to the change in the number of BBs and FBs and the change in line fine width. It is confirmed that the efficiency of the solar cell will be improved by increasing the number of FBs from 90 to 120, and increasing the line width of the FBs by about 10 ㎛ compared to the manufacturing solar cells.