• 마이크로전자및패키징학회지
• /
• 제30권2호
• /
• pp.60-64
• /
• 2023

본 연구에서는 그래핀 기반 소자의 성능에 영향을 미치는 그래핀과 금속 사이의 전기적 접촉저항 특성을 비교 분석하였다. 화학기상증착법을 이용하여 고품질의 그래핀을 합성하였으며, 전극 물질로 Al, Cu, Ni 및 Ti를 동일한 두께로 그래핀 표면 위에 증착하였다. TLM (transfer length method) 방법을 통해 SiO₂/Si 기판에 전사된 그래핀과 금속의 접촉저항을 측정한 결과, Al, Cu, Ni, Ti의 평균 접촉저항은 각각 345 Ω, 553 Ω, 110 Ω, 174 Ω으로 측정되었다. 그래핀과 물리적 흡착 특성을 갖는 Al와 Cu에 비해 화학적 결합을 형성하는 Ni과 Ti의 경우, 상대적으로 더 낮은 접촉저항을 갖는 것을 확인하였다. 본 연구의 그래핀과 금속의 전기적 특성에 대한 연구 결과는 전극과의 낮은 접촉저항 형성을 통해 고성능 그래핀 기반 전자, 광전자소자 및 센서 등의 구현에 기여할 수 있을 것으로 기대한다.

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

• 한국재료학회지
• /
• 제16권10호
• /
• pp.614-618
• /
• 2006

The thermal stability of Cu/Ti(or Ta)/NiSi contacts was investigated. Ti(Ta)-capping layers deposited to form NiSi was utilized as the Cu diffusion barrier. Ti(Ta)/NiSi contacts was thermally stable upto $600^{\circ}C$. However when Cu/Ti(Ta)/NiSi contacts were furnace-annealed at $300{\sim}400^{\circ}C$ for 40 min., the Cu diffusion was found to be effectively suppressed, but NiSi was dissociated and then Ni diffused into the Cu layer to form Cu-Ni solutions. On the other hand, the Ni diffusion did not occur for the Al/Ti/NiSi system. The thermal instability of Cu/Ti(Ta)/NiSi contacts was attributed to the high heat of solution of Ni in Cu.

• 한국태양에너지학회:학술대회논문집
• /
• 한국태양에너지학회 2009년도 추계학술발표대회 논문집
• /
• pp.350-355
• /
• 2009

The crysralline silicon solar cell where the solar cell market grows rapidly is occupying of about 85% or more high efficiency and low cost endeavors many crystalline solar cells. The fabricaion process of high efficiency crystalline silicon solar cells necessitate complicated fabrication processes and Ti/Pd/AG contact, This metal contacts have only been used in limited areas in spite of their good srability and low contact resistance because of expensive materials and process. Commercial solar cells with screen-printed solar cells formed by using Ag paste suffer from loe fill factor and high contact resistance and low aspect ratio. Ni and Cu metal contacts have been formed by using electroless plating and light-induced electro plating techniques to replace the Ti/Pd/Ag and screen-printed Ag contacts. 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 0.2~0.6${\Omega}$ cm, $20{\times}20mm^2$, CZ(Czochralski) wafer.

• 한국전기전자재료학회논문지
• /
• 제24권12호
• /
• pp.1010-1017
• /
• 2011

The use of plated front contact for metallization of silicon solar cell may alternative technologies as a screen printed and silver paste contact. This technologies should allow the formation of contact with low contact resistivity a high line conductivity and also reduction of shading losses. A selective emitter structure with highly dopes regions underneath the metal contacts, is widely known to be one of the most promising high-efficiency solution in solar cell processing. When fabricated Ni/Cu plating metallization cell with a selective emitter structure, it has been shown that efficiencies of up to 18% have been achieved using this technology.

• 한국재료학회지
• /
• 제17권9호
• /
• pp.463-468
• /
• 2007

The interdiffusion characteristics of Cu-plug/Capping Layer/NiSi contacts were investigated. Capping layers were deposited on Ni/Si to form thermally-stable NiSi and then were utilized as diffusion barriers between Cu/NiSi contacts. Four different capping layers such as Ti, Ta, TiN, and TaN with varying thickness from 20 to 100 nm were employed. When Cu/NiSi contacts without barrier layers were furnace-annealed at $400^{\circ}C$ for 40 min., Cu diffused to the NiSi layer and formed $Cu_3Si$, and thus the NiSi layer was dissociated. But for Cu/Capping Layers/NiSi, the Cu diffusion was completely suppressed for all cases. But Ni was found to diffuse into the Cu layer to form the Cu-Ni(30at.%) solid solution, regardless of material and thickness of capping layers. The source of Ni was attributed to the unreacted Ni after the silicidation heat-treatment, and the excess Ni generated by the transformation of $Ni_2Si$ to NiSi during long furnace-annealing.

• E2M - 전기 전자와 첨단 소재
• /
• 제3권4호
• /
• pp.325-331
• /
• 1990

본 연구는 텅스텐 소결에 저온 활성제로 작용하는 Ni-P 공정합금을 미량첨가하여 제조공정의 간단화를 통한 새로운 W-Cu계 전기접점제조를 목표로 하였다. 이를 위해 1회 용침공정을 통해 제조한 W(Ni-P)-Cu 합금에 대한 전기접점특성을 조사하여 접점의 미세구조 관점에서 논의하였다. Ni-P 합금첨가한 접점은 기존의 순수 W-Cu 합금에 비해 낮은 접촉저항 및 낮은 아크소모를 나타내는 우수한 접점성능을 보여주었다. 이것은 Ni-P합금이 Cu용침이 개시되기전 짧은 승온단계에서 분말간의 강한 결합과 Cu용침에 유리한 기공통로를 갖는 W 분말 골격체의 형성을 유도하기 때문인 것으로 판단된다.

• 한국태양에너지학회:학술대회논문집
• /
• 한국태양에너지학회 2009년도 춘계학술발표대회 논문집
• /
• pp.225-229
• /
• 2009

The front metal contact is one of the most important element influences in efficiency in the silicon solar cell. First of all selective of the material and formation method is important in metal contacts. Commercial solar cells with screen-printed contacts formed by using Ag paste process is simple relatively and mass production is easy. But it suffer from a low fill factor and a high shading loss because of high contact resistance. Besides Ag paste too expensive. because of depends income. This paper applied for Ni/Cu metallization replace for paste of screen printing front metal contact. Low cost Ni and Cu metal contacts have been formed by using electroless plating and electroplating techniques to replace the screen-printed Ag contacts. Ni has been proposed as a suitable silicide for the salicidation process and is expected to replace conventional silicides. Copper is a promising material for the electrical contacts in solar cells in terms of conductivity and cost. In experiments Ni/Cu metal contact applied same grid formation of screen-printed solar cell. And it has variation of different grid spacing. It was verified that the wide spacing of grid finger could increase the series resistance also the narrow spacing of grid finger also implies a grid with a higher density of grid fingers. Through different grid spacing found alteration of efficiency.

• 한국전기전자재료학회논문지
• /
• 제23권7호
• /
• pp.575-579
• /
• 2010

The technologies of Ni/Cu plating contact is attributed to the reduced series resistance caused by a better contact conductivity of Ni with Si and the subsequent electroplating of Cu on Ni. The ability to pattern narrower grid lines for reduced light shading was combined with the lower resistance of a metal silicide contact and an improved conductivity of the plated deposit. This improves the FF (fill factor) as the series resistance is reduced. This is very much requried in the case of low concentrator solar cells in which the series resistance is one of the important and dominant parameter that affect the cell performance. A Selective emitter structure with highly dopeds regions underneath the metal contacts, is widely known to be one of the most promising high-efficiency solution in solar cell processing In this paper the formation of a selective emitter, and the nickel silicide seed layer at the front side metallization of silicon cells is considered. After generating the nickel seed layer the contacts were thickened by Cu LIP (light induced plating) and by the formation of a plated Ni/Cu two step metallization on front contacts. In fabricating a Ni/Cu plating metallization cell with a selective emitter structure it has been shown that the cell efficiency can be increased by at least 0.2%.

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