• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 춘계학술발표대회 논문집
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• pp.214-219
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• 2009

In high-efficiency crystalline silicon solar cells, If high-efficiency solar cells are to be commercialized. It is need to develop superior contact formation method and material that can be inexpensive and simple without degradation of the solar cells ability. For reason of plated metallic contact is not only high metallic purity but also inexpensive manufacture. It is available to apply mass production. Especially, Nickel, Copper and Silver are applied widely in various electronic manufactures as easily formation is available by plating. 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 deposite 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 14.68 % on $0.2{\sim}0.6{\Omega}{\cdot}cm,\;20{\times}20mm^2$, CZ(Czochralski) wafer.

• Journal of the Optical Society of Korea
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• 제19권3호
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• pp.217-221
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• 2015

Developing a metallization that has low cost and high efficiency is essential in solar-cell industries, to replace expensive silver-based metallization. Ni/Cu two-step metallization is one way to reduce the cost of solar cells, because the price of copper is about 100 times less than that of silver. Alkaline electroless plating was used for depositing nickel seed layers on the front electrode area. Prior to the nickel deposition process, 2% HF solution was used to remove native oxide, which disturbs uniform nickel plating. In the subsequent step, a nickel sintering process was carried out in $N_2$ gas atmosphere; however, copper was plated by light-induced plating (LIP). Plated nickel has different properties under different bath conditions because nickel electroless plating is a completely chemical process. In this paper, plating bath conditions such as pH and temperature were varied, and the metal layer's structure was analyzed to investigate the adhesion of Ni/Cu metallization. Average adhesion values in the range of 0.2-0.49 N/mm were achieved for samples with no nickel sintering process.

• 한국표면공학회지
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• 제39권6호
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• pp.276-281
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• 2006

In order to improve the performance of PPFs (Pre-Plated Frames), a PPF that employed a Cu-Sn alloy instead of conventionally used Ni was developed and then its properties were investigated. It was found that the electoplated Cu-Sn alloy layer was a mixture of uniformly distributed fine crystallites, resulting In better wettability and crack resistance than those of Ni PPF. Moreover, as in Cu/Ni/Pd/Au PPF, migration of copper atoms from the base metal to the top of the Cu/Cu-Sn/Pd/Au PPF surface was not found although the Cu-Sn layer itself contained considerable amount of copper. It was expected that, by using the newly developed Cu-Sn PPF, any possible heat generation and signal interrupt caused by an external electro-magnetic field could be reduced because the Cu-Sn layer was paramagnetic, i.e., nonmagnetic.

• 대한금속재료학회지
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• 제49권11호
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• pp.905-909
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• 2011

The formation of front metal contact silicon solar cells is required for low cost, low contact resistance to silicon surfaces. One of the available front metal contacts is Ni/Cu plating, which can be mass produced via asimple and inexpensive process. A selective emitter, meanwhile, involves two different doping levels, with higher doping (${\leq}30{\Omega}/sq$) underneath the grid to achieve good ohmic contact and low doping between the grid in order to minimize the heavy doping effect in the emitter. This study describes the formation of a selective emitter and a nickel silicide seed layer for the front metallization of silicon cells. The contacts were thickened by a plated Ni/Cu two-step metallization process on front contacts. The experimental results showed that the Ni layer via SEM (Scanning Electron Microscopy) and EDX (Energy dispersive X-ray spectroscopy) analyses. Finally, a plated Ni/Cu contact solar cell displayed efficiency of 18.10% on a $2{\times}2cm^2$, Cz wafer.

• Membrane and Water Treatment
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• 제10권3호
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• pp.239-244
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• 2019

Plating wastewater containing various heavy metals can be produced by several industries. Specifically, we focused on the removal of copper (Cu2+) and nickel (Ni+) ions from the plating wastewater because all these ions are strictly regulated when discharged into watershed in Korea. The application of both nanofiltration (NF) and reverse osmosis (RO) technologies for the treatment of wastewater containing copper and nickel ions to reduce fresh water consumption and environmental degradation was investigated. In this work, the removal of copper (Cu2+) and nickel (Ni+) ions from synthetic water was studied on pilot scale remove by before using two commercial nanofiltration (NF) and reverse osmosis(RO) spiral-wound membrane modules (NE2521-90 and RE2521-FEN by Toray Chemical). The influence of main operating parameters such as feed concentration on the heavy metals rejection and permeate flux of both membranes, was investigated. Synthetic plating wastewater samples containing copper ($Cu^{2+}$) and nickel ($Ni^{2+}$) ions at various concentrations(1, 20, 100, 400 mg/L) were prepared and subjected to treatment by NF and RO in the pilot plant. The results showed that NF, RO process, with 98% and 99% removal for copper and nickel, respectively, could achieve high removal efficiency of the heavy metals.

• 한국재료학회지
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• 제23권11호
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• pp.661-665
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• 2013

We investigated the characteristics of electroless plated Cu films on screen printed Ag/Anodized Al substrate. Cu plating was attempted using neutral electroless plating processes to minimize damage of the anodized Al substrate; this method used sodium hypophosphite instead of formaldehyde as a reducing agent. The basic electroless solution consisted of $CuSO_4{\cdot}5H_2O$ as the main metal source, $NaH_2PO_2{\cdot}H_2O$ as the reducing agent, $C_6H_5Na_3O_7{\cdot}2H_2O$ and $NH_4Cl$ as the complex agents, and $NiSO_4{\cdot}6H_2O$ as the catalyser for the oxidation of the reducing agent, dissolved in deionized water. The pH of the Cu plating solutions was adjusted using $NH_4OH$. According to the variation of pH in the range of 6.5~8, the electroless plated Cu films were coated on screen printed Ag pattern/anodized Al/Al at $70^{\circ}C$. We investigated the surface morphology change of the Cu films using FE-SEM (Field Emission Scanning Electron Microscopy). The chemical composition of the Cu film was determined using XPS (X-ray Photoelectron Spectroscopy). The crystal structures of the Cu films were investigated using XRD (X-ray Diffraction). Using electroless plating at pH 7, the structures of the plated Cu-rich films were typical fcc-Cu; however, a slight Ni component was co-deposited. Finally, we found that the formation of Cu film plated selectively on PCB without any lithography is possible using a neutral electroless plating process.

• 한국표면공학회지
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• 제24권2호
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• pp.103-113
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• 1991

Electroless Ni-Cu-P alloy plating of Al base hard disk was performed to investigate some properties according to the change of composition. It was found that the composition of Ni and Cu in deposits changed linearly with increasing the mole ratio of NiSO4.6H2O/CuSO4.5H2O. The increase in hardness by heat - treatment was confirmed to be associated with small size grained crystallization of the amorphous deposits. Acid resistance of all deposits layer. which had been heated up to 30$0^{\circ}C$, was found to be exellent when immersed in 1N-H2SO4 solution, and it showed more superior acid resistance with decreasing Cu content and with increasing P. The resistivity of the deposits heat treated became smaller at temperature more than 50$0^{\circ}C$, and it became largerly with increasing P content. Cu 44.1wt% alloy(C bath) showed the most superior non-magnetically stable characteristics after heat treatment. It was superiorly with higher temperature and with decreasing P content.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.260-260
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• 2009

In high-efficiency crystalline silicon solar cell, If high-efficiency solar cells are to be commercialized, It is need to develop superior contact formation method and material that can be inexpensive and simple without degradation of the solar cells ability. For reason of plated metallic contact is not only high metallic purity but also inexpensive manufacture. It is available to apply mass production. Especially, Nickel, Copper are applied widely in various electronic manufactures as easily formation is available by plating. Ni is shown to be a suitable barrier to Cu diffusin as well as desirable contact metal to silicon. Nickel monosilicide has been suggested as a suitable silicide due to its lower resistivitym lower sintering temperature and lower layer stress than $TiSi_2$. In this paper, Nickel as a seed layer and diffusion barrier is plated by electroless plating to make nickel monosilicide.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.347.1-347.1
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• 2016

Screen printing is commonly used to form the electrode for crystalline silicon solar cells. However, it has caused high resistance and low aspect ratio, resulting in decrease of conversion efficiency. Accordingly, Ni/Cu/Ag plating method could be applied for crystalline silicon solar cells to reduce contact resistance. For Ni/Cu/Ag plating, laser ablation process is required to remove anti-reflection layers prior to the plating process, but laser ablation results in surface damage and then decrease of open-circuit voltage and cell efficiency. Another issue with plating process is ghost plating. Ghost plating occurred in the non-metallized region, resulting from pin-hole in anti-reflection layer. In this paper, we investigated the effect of Ni/Cu/Ag plating on the electrical properties, compared to screen printing method. In addition, phosphoric acid layer was spin-coated prior to laser ablation to minimize emitter damage by the laser. Phosphorous elements in phosphoric acid generated selective emitter throughout emitter layer during laser process. Then, KOH treatment was applied to remove surface damage by laser. At this step, amorphous silicon formed by laser ablation was recrystallized during firing process and remaining of amorphous silicon was removed by KOH treatment. As a result, electrical properties as Jsc, FF and efficiency were improved, but Voc was lower than screen printed solar cells because Voc was decreased due to surface damage by laser process. Accordingly, we expect that efficiency of solar cells could be improved by optimization of the process to remove surface damage.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2011년도 춘계학술대회 및 Fine pattern PCB 표면 처리 기술 워크샵
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• pp.205-206
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• 2011

Cu thin films for electromagnetic wave shielding were prepared on PET film and Ni-coated PET film by using Dry and Wet coating method, such as evaporation method, DC sputtering method and copper sulfate($CuSO_4$). After that, Zn thin film and Ni thin film were prepared onto the Cu thin films by using evaporation dry process and Ni electro plating wet process as a finishing treatment, respectively. The result of conductivity test and corrosion resistance test revealed Cu thin films which were formed with bigger grain size and high Cu composition rate have superior properties. Zn thin film by dry evaporation process and Ni thin film by wet electro plating process on Cu thin films were largely contributed to corrosion resistance. However, Ni thin film by wet process made conductivity of all specimen worse, the other hand, Zn thin film by dry process made it better to improve condictivity of specimens just prepared by dry process.