WO2017204422A1 - Solar cell and manufacturing method therefor - Google Patents

Solar cell and manufacturing method therefor Download PDF

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Publication number
WO2017204422A1
WO2017204422A1 PCT/KR2016/012272 KR2016012272W WO2017204422A1 WO 2017204422 A1 WO2017204422 A1 WO 2017204422A1 KR 2016012272 W KR2016012272 W KR 2016012272W WO 2017204422 A1 WO2017204422 A1 WO 2017204422A1
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WIPO (PCT)
Prior art keywords
solar cell
glass frit
insulating layer
bus bar
substrate
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PCT/KR2016/012272
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French (fr)
Korean (ko)
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장윤현
김훈
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알무스인터내셔널 주식회사
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Publication of WO2017204422A1 publication Critical patent/WO2017204422A1/en

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    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C8/00—Enamels; Glazes; Fusion seal compositions being frit compositions having non-frit additions
    • C03C8/02—Frit compositions, i.e. in a powdered or comminuted form
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H01B1/14—Conductive material dispersed in non-conductive inorganic material
    • H01B1/16—Conductive material dispersed in non-conductive inorganic material the conductive material comprising metals or alloys
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B5/00—Non-insulated conductors or conductive bodies characterised by their form
    • H01B5/14—Non-insulated conductors or conductive bodies characterised by their form comprising conductive layers or films on insulating-supports
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/02—Details
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/02—Details
    • H01L31/0216—Coatings
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/02—Details
    • H01L31/0224—Electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/04—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/18—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the present invention relates to a solar cell and a method of manufacturing the same, and more particularly, to a solar cell comprising a conductive paste containing a glass frit and a method of manufacturing the same.
  • Solar cells using renewable energy are based on semiconductor technology, a major player in technological development of the 20th century. It is clear that solar energy generation is an important global energy collector that determines human survival.
  • the conversion of solar energy into electrical energy is to reduce or eliminate the use of silver (Ag) and lead (Pb), which are used in electrodes in an era where not only efficiency but also manufacturing cost reduction and pollution-free eco-friendly power generation equipment are most important. It's getting important.
  • FIG. 1 is a cross-sectional view of a general solar cell structure.
  • a diffusion doped layer 11 is formed to reflect the N-type / P-type silicon substrate 10 and the silicon substrate 10 to convert solar energy into electrical energy.
  • a rear electrode 60 is formed on the rear surface of the silicon substrate 10.
  • the bus bar 40 and the finger electrode 30 are generally manufactured by screen printing silver paste.
  • Silver paste is composed of 90wt% to 95wt% silver (Ag), 3wt% to 5wt% frit, the rest of the organic solvent.
  • the glass frit used for the busbar 40 and the finger electrode 30 contains lead which can be plastically processed at a relatively low temperature.
  • the amount of silver used and the amount of lead used must be reduced or eliminated, while maintaining the efficiency of the solar cell.
  • An object of the present invention is to reduce the manufacturing cost of solar cells, to provide an environmentally friendly solar cell and a method of manufacturing the same.
  • a solar cell according to an embodiment of the present invention is a solar cell including a substrate, a diffusion doping layer formed on the substrate, and an insulating layer formed on the diffusion doping layer, the busbar (busbar) formed on the insulating layer And a finger electrode formed through a predetermined region of the insulating layer to connect the diffusion doping layer and the bus bar, wherein the bus bar uses a conductive paste containing a conductive glass frit. Is formed.
  • the conductive paste may include 20 wt% to 70 wt% of conductive glass frit.
  • the conductive glass frit may include vanadium glass containing vanadium (V), barium (Ba), and iron (Fe).
  • the solar cell according to the embodiment of the present invention may further include a lead electrode on the bus bar.
  • the solar cell and the manufacturing method thereof by reducing the content of silver contained in the conductive paste to reduce the manufacturing cost, by reducing or eliminating the content of lead, it is possible to produce an environmentally friendly solar cell.
  • FIG. 1 is a cross-sectional view of a general solar cell structure.
  • FIG. 2 is a cross-sectional view of a solar cell according to an embodiment of the present invention.
  • 3 is an actual picture of a bus bar according to an embodiment of the present invention.
  • FIG. 4 is an actual enlarged photograph of a bus bar according to an embodiment of the present invention.
  • FIG. 5 is a flow chart of a solar cell manufacturing method according to an embodiment of the present invention.
  • FIG. 6 is a solar cell process description according to an embodiment of the present invention.
  • first or second may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another, for example without departing from the scope of the rights according to the inventive concept, and the first component may be called a second component and similarly the second component. The component may also be referred to as a first component.
  • Each block or step may represent a portion of a module, segment or code containing one or more executable instructions for executing a specified logical function (s). It should also be noted that in some alternative embodiments, the functions noted in the blocks or steps may occur out of order. For example, the two blocks or steps shown in succession may in fact be executed substantially concurrently or the blocks or steps may sometimes be performed in the reverse order, depending on the functionality involved.
  • FIG. 2 is a cross-sectional view of a solar cell according to an embodiment of the present invention.
  • a solar cell As shown in FIG. 2, a solar cell according to an exemplary embodiment of the present invention has a substrate 100, an insulation doping layer 200 formed on the substrate 100, and an insulation formed on the diffusion doping layer 200.
  • a solar cell comprising a layer 300, comprising a busbar 400 formed on the insulating layer 300, wherein the diffusion doped layer 200 and the busbar 400 are connected to each other.
  • the finger electrode 500 is formed to penetrate a predetermined region of the insulating layer 300, and the bus bar 400 is formed using a conductive paste containing a conductive glass frit.
  • the substrate 100 may be a silicon substrate generally used.
  • the diffusion doped layer 200 may be an impurity doped in the silicon substrate to form an N-type doped layer when the substrate is a P-type semiconductor, but is not necessarily limited thereto.
  • the insulating layer 300 is a layer having no conductivity, and may be a silicon nitride film, and the silicon nitride film may function as an antireflection film that prevents reflection of incident sunlight.
  • the bus bar 400 is a place where electrons in the diffusion doped layer 200 move and collect, and may be formed using a conductive paste containing a conductive glass frit, and the conductive paste may be 20wt% to 70wt%.
  • Conductive glass frit includes vanadate glass containing vanadium (V), barium (Ba) and iron (Fe).
  • the finger electrode 500 is a conductive path connecting the diffusion doping layer 200 and the bus bar 400, but may be a material in which lead glass is mixed with Ag as a frit, but is not necessarily limited thereto. .
  • the finger electrode fires through the insulating layer 300 through a firing process and is connected to the diffusion doping layer 200.
  • the solar cell according to the exemplary embodiment of the present invention further includes a lead electrode 600 on the bus bar 400.
  • the lead electrode 600 is conductive as a path for moving electrons in the bus bar 400, and generally uses silver or copper conductors.
  • the lead electrode 600 is firmly coupled to the bus bar 400 by plastic working in order to reduce contact resistance.
  • the solar cell according to the embodiment of the present invention further includes a back electrode 700 under the substrate.
  • the back electrode 700 is positioned in a direction opposite to the direction in which sunlight is incident and is connected to the lead electrode 600 as a conductor to form a potential difference so that electrons can flow along the lead electrode 600.
  • the bus bar 400 is formed by using a conductive paste, but the weight ratio of the conductive glass frit included in the conductive paste is 20 wt% to 70 wt%.
  • the conversion efficiency of the solar cell according to the embodiment of the present invention using the conductive paste prepared by reducing the content of silver in the conductive paste and the content of the conductive glass frit to 22.7 wt%, 50 wt%, and 66.8 wt% is shown in Table 1 below. Same as
  • the conversion efficiency is a value representing the energy output of the solar cell based on the incident solar energy
  • the conversion efficiency of Experimental Examples 1 to 3 is a conductive paste using only silver (Ag) without using an actual conductive glass frit. It can be seen that the value is almost similar to. That is, silver (Ag) can be replaced by using the conductive properties of the conductive glass frit.
  • 3 is an actual picture of a bus bar according to an embodiment of the present invention.
  • FIG. 4 is an actual enlarged photograph of a bus bar according to an embodiment of the present invention.
  • the bus bar is formed in the longitudinal direction of the solar cell and is a passage through which electrons move.
  • silver (Ag) is uniformly distributed when fired with a pleat containing silver (Ag) and lead (Pb) components.
  • silver (Ag) and the conductive glass frit are fired to form a bus bar as shown in FIGS. 3 and 4, and in this case, the conductive glass frit is formed on both sides of the bus bar as shown in FIG. 4. It is formed and it can confirm that silver (Ag) is gathered and formed in the center.
  • Silver (Ag) is gathered at the center of the busbar to improve conductivity (conductivity improves compared to when silver (Ag) was uniformly dispersed), and the conductive glass frit also has conductivity as the name suggests. Increasing the content in the conductive paste instead of (Ag) it can be confirmed that the conversion efficiency is not significantly reduced as shown in Table 1.
  • the firing temperature for the plastic working may be 400 °C to 600 °C.
  • the conductive glass frit includes vanadium glass containing vanadium (V), barium (Ba) and iron (Fe).
  • vanadium glass containing vanadium (V), barium (Ba) and iron (Fe) In particular, iron is strongly bonded internally and stays therein, and even when mixed with other materials, the bonding property is extremely small.
  • the conversion efficiency shown in Table 1 is that the glass frit has conductivity, the silver contained in the conductive paste is separated from the glass, and the conductivity is improved. This is because the conductivity of silver (Ag) is improved by suppressing the growth of, and the conductive glass frit used to form the busbar electrode does not cause a firing phenomenon and thus a reduction in conversion efficiency does not occur.
  • FIG. 5 is a flow chart of a solar cell manufacturing method according to an embodiment of the present invention.
  • FIG. 6 is a solar cell process description according to an embodiment of the present invention.
  • the solar cell manufacturing method according to an embodiment of the present invention further comprises the step of forming a lead electrode on the bus bar (S900).
  • Preparing the substrate 100 (S100) may further include preparing a semiconductor silicon substrate and cleaning the same.
  • a high electron concentration region is formed on the substrate by doping impurities.
  • the diffusion doped layer 200 allows sunlight to enter and move electrons to the busbar.
  • the insulating layer 300 for separating the diffusion doped layer 200 and the bus bar 400 is formed.
  • the insulating layer 300 may be a silicon nitride film and may also function as an anti-reflection film.
  • the finger electrode 500 is screen printed on the insulating layer 300.
  • a printing material a mixture of lead glass as silver and frit may be used, but is not necessarily limited thereto.
  • the pattern of the screen-printed finger electrode 500 (mixing of silver and lead glass pleats) is performed. Water) is fired at a high temperature to fire through the insulating layer (silicon nitride film) 300 so that the finger electrode 500 penetrates the insulating layer 300.
  • the finger electrode 500 is connected to the diffusion doping layer 200 to become a passage through which electrons move in the diffusion doping layer 200.
  • the first firing is heated at a temperature of 100 ° C. to 200 ° C. for about 20 seconds to 1 minute to process the finger electrode 500.
  • the step S600 of forming the bus bar 400 using the conductive paste containing the conductive glass frit on the insulating layer 300 may be connected to the finger electrode 500 on the insulating layer 300.
  • the busbar 400 is formed through screen printing.
  • the bus bar 400 uses a conductive paste, but the conductive paste includes a conductive glass frit.
  • the conductive paste includes 20 wt% to 70 wt% of conductive glass frit, and the conductive glass frit is made of vanadium (V), barium (Ba), iron (Fe), and the like.
  • the conductive paste generally contains silver (Ag) and may contain copper (Cu), but copper (Cu) is easily oxidized, which causes a problem of poor efficiency as an electrode.
  • the second baking process is performed by heating the pattern of the screen-printed bus bar 400, but the firing time is within 2 minutes. Second to 3 seconds or more can be heated, the firing temperature may be about 400 °C to 600 °C.
  • conductive glass frits particularly barium, are formed in the form of particles on both sides of the bus bar, and silver (Ag) is collected at the center portion.
  • silver (Ag) is collected at the center portion.
  • the conductive glass frit also has conductivity to move electrons, even if the content of silver (Ag) is reduced, the overall conversion efficiency of the solar cell does not change significantly.
  • the lead glass (Pb) is not contained in the conductive glass frit, there is no fear of environmental pollution.
  • the step S800 of forming the back electrode 700 under the substrate 100 is a process of forming the conductive back electrode 700 on a surface opposite to the surface where the solar light is incident on the substrate 100.
  • the process of forming the electrode uses a general method of forming the electrode on the semiconductor process, so a detailed description thereof will be omitted.
  • the step S900 of forming the lead electrode 600 on the bus bar 400 forms a lead electrode 600 that electrically connects the bus bar 400 so that the electrons in the bus bar 400 can move. do.
  • the solar cell manufactured using the manufacturing method described above uses a bus bar 400 provided by screen printing a conductive paste prepared by mixing a conductive glass frit and silver (Ag) powder in an organic solvent with an organic solvent.
  • a bus bar 400 provided by screen printing a conductive paste prepared by mixing a conductive glass frit and silver (Ag) powder in an organic solvent with an organic solvent.
  • the content of silver (Ag) can be reduced due to the property of the conductive glass frit, and the conductive glass frit does not contain lead (Pb), which makes it possible to manufacture solar cells without the risk of environmental pollution.

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Abstract

According to an embodiment of the present invention, a solar cell, comprising a substrate, a diffusion doping layer formed on the substrate, and an insulation layer formed on the diffusion doping layer, comprises: a busbar formed on the insulation layer; and a finger electrode formed so as to penetrate a predetermined region of the insulation layer such that the diffusion doping layer is connected to the busbar, wherein the busbar is formed by using a conductive paste containing a conductive glass frit.

Description

태양전지 및 이의 제조방법Solar cell and manufacturing method thereof
본 발명은 태양전지 및 이를 제조하는 방법에 관한 발명으로서, 보다 상세하게는 유리프릿이 함유된 도전성 페이스트를 포함하는 태양전지 및 이를 제조하는 방법에 관한 것이다.The present invention relates to a solar cell and a method of manufacturing the same, and more particularly, to a solar cell comprising a conductive paste containing a glass frit and a method of manufacturing the same.
신재생에너지를 이용한 태양전지는 20세기 기술발전의 주역인 반도체 기술을 기반으로 하고 있다. 태양광 에너지 발전이 인류의 생존을 좌우하는 전 지구차원의 중요한 에너지 수집원임은 자명하다. 태양광 에너지를 이용한 전기에너지로의 변환은 효율 뿐만 아니라 제조원가절감 및 무공해 친환경 발전장치의 제조가 무엇보다 중요한 시대에 전극에 사용되고 있는 은(Ag)이나 납(Pb)의 사용량을 저감시키거나 없애는 것이 중요해지고 있다.Solar cells using renewable energy are based on semiconductor technology, a major player in technological development of the 20th century. It is clear that solar energy generation is an important global energy collector that determines human survival. The conversion of solar energy into electrical energy is to reduce or eliminate the use of silver (Ag) and lead (Pb), which are used in electrodes in an era where not only efficiency but also manufacturing cost reduction and pollution-free eco-friendly power generation equipment are most important. It's getting important.
도 1은 일반적인 태양전지 구조의 단면도이다.1 is a cross-sectional view of a general solar cell structure.
도 1과 같이 일반적인 태양전지 구조는 확산도핑층(11)이 형성되어, 태양광 에너지를 전기에너지로 변환하는 N형/P형 실리콘 기판(10)과 실리콘 기판(10)의 표면에 형성되는 반사방지 및 절연체 박막인 질화실리콘(20), 실리콘 기판(10) 중에 발생하는 전자가 이동하는 통로인 핑거전극(30), 핑거전극(30)에서 이동하는 전자를 모으는 버스바(40), 버스바(40)에 모인 전자가 외부로 이동하는 리드전극(50)으로 구성된다. 또한, 실리콘 기판(10)의 후면에는 후면전극(60)이 형성되어 있다.As shown in FIG. 1, in the general solar cell structure, a diffusion doped layer 11 is formed to reflect the N-type / P-type silicon substrate 10 and the silicon substrate 10 to convert solar energy into electrical energy. Silicon nitride 20, which is a thin film for prevention and insulator, finger electrode 30, which is a passage through which electrons generated in the silicon substrate 10 move, bus bar 40, which collects electrons moving from the finger electrode 30, and a bus bar Electrons collected at 40 are composed of lead electrodes 50 which move to the outside. In addition, a rear electrode 60 is formed on the rear surface of the silicon substrate 10.
버스바(40)와 핑거전극(30)은 일반적으로 실버페이스트를 스크린 인쇄하여 제조한다. 실버페이스트는 90wt% 내지 95wt%의 은(Ag)과 3wt% 내지 5wt%의 프릿(frit), 나머지는 유기용매로 이루어져 있다.The bus bar 40 and the finger electrode 30 are generally manufactured by screen printing silver paste. Silver paste is composed of 90wt% to 95wt% silver (Ag), 3wt% to 5wt% frit, the rest of the organic solvent.
버스바(40) 및 핑거전극(30)에 사용되는 유리프릿(glass frit)에는 비교적 낮은 온도에서 소성가공이 가능한 납을 함유하고 있다.The glass frit used for the busbar 40 and the finger electrode 30 contains lead which can be plastically processed at a relatively low temperature.
결국, 태양전지를 저비용, 친환경적으로 탈바꿈시키기 위해서는 은의 사용량을 저감시키고 납의 사용량을 저감하거나 제거해야만 하고, 동시에 태양 전지의 효율을 유지할 수 있어야만 한다.As a result, in order to transform the solar cell into a low cost and environmentally friendly environment, the amount of silver used and the amount of lead used must be reduced or eliminated, while maintaining the efficiency of the solar cell.
본 발명의 목적은 태양전지의 제조원가를 절감하고, 친환경적인 태양전지 및 이를 제조하는 방법을 제공하는데 있다.An object of the present invention is to reduce the manufacturing cost of solar cells, to provide an environmentally friendly solar cell and a method of manufacturing the same.
본 발명의 실시예에 따른 태양전지는 기판, 상기 기판상에 형성되는 확산도핑층 및 상기 확산도핑층 상에 형성되는 절연층을 포함하는 태양전지로서, 상기 절연층 상에 형성되는 버스바(busbar)를 포함하고, 상기 확산도핑층과 상기 버스바가 연결되도록 상기 절연층의 소정영역을 관통하여 형성되는 핑거전극을 포함하되, 상기 버스바는 도전성 유리프릿(glass frit)을 함유한 도전성 페이스트를 이용하여 형성된다.A solar cell according to an embodiment of the present invention is a solar cell including a substrate, a diffusion doping layer formed on the substrate, and an insulating layer formed on the diffusion doping layer, the busbar (busbar) formed on the insulating layer And a finger electrode formed through a predetermined region of the insulating layer to connect the diffusion doping layer and the bus bar, wherein the bus bar uses a conductive paste containing a conductive glass frit. Is formed.
여기서, 상기 도전성 페이스트는 20wt% 내지 70wt%의 도전성 유리프릿을 포함할 수 있다.The conductive paste may include 20 wt% to 70 wt% of conductive glass frit.
또한, 상기 도전성 유리프릿은 바나듐(V), 바륨(Ba) 및 철(Fe)을 함유한 바나듐산유리를 포함할 수 있다.In addition, the conductive glass frit may include vanadium glass containing vanadium (V), barium (Ba), and iron (Fe).
본 발명의 실시예에 따른 태양전지는 상기 버스바 상에 리드전극을 더 포함할 수 있다.The solar cell according to the embodiment of the present invention may further include a lead electrode on the bus bar.
본 발명의 실시예에 따른 태양전지 및 이의 제조방법에 의하면, 도전성 페이스트에 함유되는 은의 함량을 줄여 제조원가를 절감하고, 납의 함량을 줄이거나 없앰으로서, 친환경적인 태양전지의 생산이 가능하다.According to the solar cell and the manufacturing method thereof according to an embodiment of the present invention, by reducing the content of silver contained in the conductive paste to reduce the manufacturing cost, by reducing or eliminating the content of lead, it is possible to produce an environmentally friendly solar cell.
도 1은 일반적인 태양전지 구조의 단면도이다.1 is a cross-sectional view of a general solar cell structure.
도 2는 본 발명의 실시예에 따른 태양전지의 단면도이다.2 is a cross-sectional view of a solar cell according to an embodiment of the present invention.
도 3은 본 발명의 실시예에 따른 버스바의 실제사진이다.3 is an actual picture of a bus bar according to an embodiment of the present invention.
도 4는 본 발명의 실시예에 따른 버스바의 실제 확대사진이다.4 is an actual enlarged photograph of a bus bar according to an embodiment of the present invention.
도 5는 본 발명의 실시예에 따른 태양전지 제조방법의 순서도이다.5 is a flow chart of a solar cell manufacturing method according to an embodiment of the present invention.
도 6은 본 발명의 실시예에 따른 태양전지 공정설명도이다.6 is a solar cell process description according to an embodiment of the present invention.
본 명세서에 개시되어 있는 본 발명의 개념에 따른 실시 예들에 대해서 특정한 구조적 또는 기능적 설명은 단지 본 발명의 개념에 따른 실시 예들을 설명하기 위한 목적으로 예시된 것으로서, 본 발명의 개념에 따른 실시 예들은 다양한 형태들로 실시될 수 있으며 본 명세서에 설명된 실시 예들에 한정되지 않는다.Specific structural or functional descriptions of the embodiments according to the inventive concept disclosed herein are provided only for the purpose of describing the embodiments according to the inventive concept. It may be embodied in various forms and is not limited to the embodiments described herein.
본 발명의 개념에 따른 실시 예들은 다양한 변경들을 가할 수 있고 여러 가지 형태들을 가질 수 있으므로 실시 예들을 도면에 예시하고 본 명세서에서 상세하게 설명하고자 한다. 그러나, 이는 본 발명의 개념에 따른 실시 예들을 특정한 개시 형태들에 대해 한정하려는 것이 아니며, 본 발명의 사상 및 기술 범위에 포함되는 모든 변경, 균등물, 또는 대체물을 포함한다.Embodiments according to the inventive concept may be variously modified and have various forms, so embodiments are illustrated in the drawings and described in detail herein. However, this is not intended to limit the embodiments in accordance with the concept of the invention to the specific forms disclosed, it includes all changes, equivalents, or substitutes included in the spirit and scope of the present invention.
제1 또는 제2 등의 용어는 다양한 구성 요소들을 설명하는데 사용될 수 있지만, 상기 구성 요소들은 상기 용어들에 의해 한정되어서는 안 된다. 상기 용어들은 하나의 구성 요소를 다른 구성 요소로부터 구별하는 목적으로만, 예컨대 본 발명의 개념에 따른 권리 범위로부터 벗어나지 않은 채, 제1 구성 요소는 제2 구성 요소로 명명될 수 있고 유사하게 제2 구성 요소는 제1 구성 요소로도 명명될 수 있다.Terms such as first or second may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another, for example without departing from the scope of the rights according to the inventive concept, and the first component may be called a second component and similarly the second component. The component may also be referred to as a first component.
어떤 구성 요소가 다른 구성 요소에 "연결되어" 있다거나 "접속되어" 있다고 언급된 때에는, 그 다른 구성 요소에 직접적으로 연결되어 있거나 또는 접속되어 있을 수도 있지만, 중간에 다른 구성 요소가 존재할 수도 있다고 이해되어야 할 것이다. 반면에, 어떤 구성 요소가 다른 구성 요소에 "직접 연결되어" 있다거나 "직접 접속되어" 있다고 언급된 때에는 중간에 다른 구성 요소가 존재하지 않는 것으로 이해되어야 할 것이다. 구성 요소들 간의 관계를 설명하는 다른 표현들, 즉 "~사이에"와 "바로 ~사이에" 또는 "~에 이웃하는"과 "~에 직접 이웃하는" 등도 마찬가지로 해석되어야 한다.When a component is said to be "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may exist in the middle. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that no other component exists in the middle. Other expressions describing the relationship between components, such as "between" and "immediately between" or "neighboring to" and "directly neighboring", should be interpreted as well.
본 명세서에서 사용한 용어는 단지 특정한 실시 예를 설명하기 위해 사용된 것으로서, 본 발명을 한정하려는 의도가 아니다. 단수의 표현은 문맥상 명백하게 다르게 뜻하지 않는 한, 복수의 표현을 포함한다. 본 명세서에서, "포함하다" 또는 "가지다" 등의 용어는 본 명세서에 기재된 특징, 숫자, 단계, 동작, 구성 요소, 부분품 또는 이들을 조합한 것이 존재함을 지정하려는 것이지, 하나 또는 그 이상의 다른 특징들이나 숫자, 단계, 동작, 구성 요소, 부분품 또는 이들을 조합한 것들의 존재 또는 부가 가능성을 미리 배제하지 않는 것으로 이해되어야 한다.The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as "comprise" or "have" are intended to indicate that there is a feature, number, step, action, component, part, or combination thereof described herein, but one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, parts or combinations thereof.
각 블록 또는 각 단계는 특정된 논리적 기능(들)을 실행하기 위한 하나 이상의 실행 가능한 인스트럭션들을 포함하는 모듈, 세그먼트 또는 코드의 일부를 나타낼 수 있다. 또, 몇 가지 대체 실시예들에서는 블록들 또는 단계들에서 언급된 기능들이 순서를 벗어나서 발생하는 것도 가능함을 주목해야 한다. 예컨대, 잇달아 도시되어 있는 두 개의 블록들 또는 단계들은 사실 실질적으로 동시에 수행되는 것도 가능하고 또는 그 블록들 또는 단계들이 때때로 해당하는 기능에 따라 역순으로 수행되는 것도 가능하다.Each block or step may represent a portion of a module, segment or code containing one or more executable instructions for executing a specified logical function (s). It should also be noted that in some alternative embodiments, the functions noted in the blocks or steps may occur out of order. For example, the two blocks or steps shown in succession may in fact be executed substantially concurrently or the blocks or steps may sometimes be performed in the reverse order, depending on the functionality involved.
다르게 정의되지 않는 한, 기술적이거나 과학적인 용어를 포함해서 여기서 사용되는 모든 용어들은 본 발명이 속하는 기술 분야에서 통상의 지식을 가진 자에 의해 일반적으로 이해되는 것과 동일한 가진다. 일반적으로 사용되는 사전에 정의되어 있는 것과 같은 용어들은 관련 기술의 문맥상 가지는 의미와 일치하는 의미를 갖는 것으로 해석되어야 하며, 본 명세서에서 명백하게 정의하지 않는 한, 이상적이거나 과도하게 형식적인 의미로 해석되지 않는다.Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art, and are not construed in ideal or excessively formal meanings unless expressly defined herein. Do not.
또한, 특정한 경우는 출원인이 임의로 선정한 용어도 있으며, 이 경우 해당되는 설명 부분에서 상세한 그 의미를 기재할 것이다. 따라서 아래 설명에서 사용되는 용어는 단순한 용어의 명칭이 아닌 그 용어가 가지는 의미와 명세서 전반에 걸친 내용을 토대로 이해되어야 한다.In addition, in certain cases, there is a term arbitrarily selected by the applicant, and in this case, the meaning will be described in detail in the corresponding description. Therefore, the terms used in the following description should be understood based on the meanings of the terms and the contents throughout the specification, rather than simply the names of the terms.
이하, 본 명세서에 첨부된 도면들을 참조하여 본 발명의 실시 예들을 상세히 설명한다.Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
도 2는 본 발명의 실시예에 따른 태양전지의 단면도이다.2 is a cross-sectional view of a solar cell according to an embodiment of the present invention.
도 2에 도시된 바와 같이 본 발명의 실시예에 따른 태양전지는 기판(100), 상기 기판(100)상에 형성되는 확산도핑층(200) 및 상기 확산도핑층(200) 상에 형성되는 절연층(300)을 포함하는 태양전지로서, 상기 절연층(300)상에 형성되는 버스바(busbar)(400)를 포함하고, 상기 확산도핑층(200)과 상기 버스바(400)가 연결되도록 상기 절연층(300)의 소정영역을 관통하여 형성되는 핑거전극(500)을 포함하되, 상기 버스바(400)는 도전성 유리프릿(glass frit)을 함유한 도전성 페이스트를 이용하여 형성된다.As shown in FIG. 2, a solar cell according to an exemplary embodiment of the present invention has a substrate 100, an insulation doping layer 200 formed on the substrate 100, and an insulation formed on the diffusion doping layer 200. A solar cell comprising a layer 300, comprising a busbar 400 formed on the insulating layer 300, wherein the diffusion doped layer 200 and the busbar 400 are connected to each other. The finger electrode 500 is formed to penetrate a predetermined region of the insulating layer 300, and the bus bar 400 is formed using a conductive paste containing a conductive glass frit.
기판(100)은 일반적으로 사용되는 실리콘 기판일 수 있다.The substrate 100 may be a silicon substrate generally used.
확산도핑층(200)은 실리콘 기판에 불순물 도핑하여 기판이 P형 반도체인 경우에는 N형 도핑층을 형성할 수 있으나 반드시 이에 제한되는 것은 아니다.The diffusion doped layer 200 may be an impurity doped in the silicon substrate to form an N-type doped layer when the substrate is a P-type semiconductor, but is not necessarily limited thereto.
절연층(300)은 도전성이 없는 층으로서, 질화실리콘막일 수 있으며, 질화실리콘막은 입사하는 태양광의 반사를 방지하는 반사방지막의 기능을 수행할 수 있다.The insulating layer 300 is a layer having no conductivity, and may be a silicon nitride film, and the silicon nitride film may function as an antireflection film that prevents reflection of incident sunlight.
버스바(400)는 확산도핑층(200)에 있는 전자들이 이동하여 모이는 곳으로, 도전성 유리프릿(glass frit)을 함유한 도전성 페이스트를 이용하여 형성될 수 있으며, 도전성 페이스트는 20wt% 내지 70wt%의 도전성 유리프릿을 포함한다. 또한, 도전성 유리프릿은 바나듐(V), 바륨(Ba) 및 철(Fe)을 함유한 바나듐산유리를 포함한다.The bus bar 400 is a place where electrons in the diffusion doped layer 200 move and collect, and may be formed using a conductive paste containing a conductive glass frit, and the conductive paste may be 20wt% to 70wt%. Conductive glass frit. In addition, the conductive glass frit includes vanadate glass containing vanadium (V), barium (Ba) and iron (Fe).
핑거전극(500)은 확산도핑층(200)과 버스바(400)를 연결하는 도전성 통로로서, 은(Ag)에 프릿(Frit)으로서 납유리를 혼합한 재료를 사용할 수도 있으나 반드시 이에 제한되는 것은 아니다. 핑거전극은 소성과정을 통해 절연층(300)을 파이어 스루시켜 확산도핑층(200)과 연결된다.The finger electrode 500 is a conductive path connecting the diffusion doping layer 200 and the bus bar 400, but may be a material in which lead glass is mixed with Ag as a frit, but is not necessarily limited thereto. . The finger electrode fires through the insulating layer 300 through a firing process and is connected to the diffusion doping layer 200.
본 발명의 실시예에 따른 태양전지는 버스바(400) 상에 리드전극(600)을 더 포함한다.The solar cell according to the exemplary embodiment of the present invention further includes a lead electrode 600 on the bus bar 400.
리드전극(600)은 버스바(400)에 있는 전자들을 이동시키는 통로로서 도전성을 갖고 있으며, 일반적으로 은이나 구리도선을 이용한다. 리드전극(600)은 버스바(400)와 접촉저항을 줄이기 위해서 소성가공에 의해 공고히 결합되어 있다.The lead electrode 600 is conductive as a path for moving electrons in the bus bar 400, and generally uses silver or copper conductors. The lead electrode 600 is firmly coupled to the bus bar 400 by plastic working in order to reduce contact resistance.
본 발명의 실시예에 따른 태양전지는 기판의 하부에 후면전극(700)을 더 포함한다. 후면전극(700)은 태양광이 입사하는 방향의 반대방향에 위치해 있으며, 리드전극(600)과 도전체로 연결되어 있어 전위차를 형성하여 리드전극(600)을 따라서 전자가 흐를 수 있도록 한다.The solar cell according to the embodiment of the present invention further includes a back electrode 700 under the substrate. The back electrode 700 is positioned in a direction opposite to the direction in which sunlight is incident and is connected to the lead electrode 600 as a conductor to form a potential difference so that electrons can flow along the lead electrode 600.
이상 본 발명의 실시예에 따른 태양전지의 각 구성부분에 대해서 살펴보았다. 본 발명의 실시예에 따른 태양전지는 버스바(400)를 도전성 페이스트를 이용하여 형성하되, 도전성 페이스트에 포함되어 있는 도전성 유리프릿의 중량비가 20wt% 내지 70wt%이다.Above has been described with respect to each component of the solar cell according to an embodiment of the present invention. In the solar cell according to the exemplary embodiment of the present invention, the bus bar 400 is formed by using a conductive paste, but the weight ratio of the conductive glass frit included in the conductive paste is 20 wt% to 70 wt%.
도전성 페이스트에서 은의 함량을 줄이고 도전성 유리프릿의 함량을 22.7wt%, 50wt%, 66.8wt%로 하여 제조된 도전성 페이스트를 이용한 본 발명의 실시예에 따른 태양전지의 변환효율을 측정한 결과는 표 1과 같다.The conversion efficiency of the solar cell according to the embodiment of the present invention using the conductive paste prepared by reducing the content of silver in the conductive paste and the content of the conductive glass frit to 22.7 wt%, 50 wt%, and 66.8 wt% is shown in Table 1 below. Same as
구분division 도전성 유리프릿의 함량(wt%)Content of Conductive Glass Frit (wt%) 변환효율Conversion efficiency
실험예1Experimental Example 1 22.722.7 약15.1%About 15.1%
실험예2Experimental Example 2 5050 약16.6%About 16.6%
실험예3Experimental Example 3 66.866.8 약15.7%About 15.7%
비교예1Comparative Example 1 00 약17%About 17%
여기서 변환효율은 입사하는 태양광 에너지를 기준으로 태양전지의 에너지 생산량을 비율로 나타낸 값으로서, 실험예1 내지 3의 변환효율은 실제 도전성 유리프릿을 사용하지 않고 은(Ag)만을 사용하는 도전성 페이스트와 거의 비슷한 값을 갖는 것을 확인할 수 있다. 즉 도전성 유리프릿의 전도특성을 이용하여 은 (Ag)을 대체할 수 있다.Here, the conversion efficiency is a value representing the energy output of the solar cell based on the incident solar energy, and the conversion efficiency of Experimental Examples 1 to 3 is a conductive paste using only silver (Ag) without using an actual conductive glass frit. It can be seen that the value is almost similar to. That is, silver (Ag) can be replaced by using the conductive properties of the conductive glass frit.
도 3은 본 발명의 실시예에 따른 버스바의 실제사진이다.3 is an actual picture of a bus bar according to an embodiment of the present invention.
도 4는 본 발명의 실시예에 따른 버스바의 실제 확대사진이다.4 is an actual enlarged photograph of a bus bar according to an embodiment of the present invention.
도 3과 도 4를 보면, 버스바는 태양전지의 길이방향으로 형성되어 있으며, 전자가 이동하는 통로이다. 종래 은(Ag)과 납(Pb)성분을 포함하고 있는 플리트(Frit)로 소성한 경우에 은(Ag)은 균일하게 분포한다. 본 발명의 실시예에 따른 태양전지는 은(Ag)과 도전성 유리프릿을 소성하여 도3, 도4와 같은 버스바를 형성하고, 이 경우 도4와 같이 버스바의 양측에 도전성 유리프릿이 입자상으로 형성되어 있으며, 중앙에 은(Ag)이 모여서 형성되어 있는 것을 확인할 수 있다. 은(Ag)은버스바의 중앙부분에 모여 있어 도전성이 향상되고(종래 은(Ag)이 균일하게 분산되어 있었을 경우와 비교하여 도전성이 향상), 도전성 유리프릿도 명칭과 같이 전도성을 가지는 것으로 은(Ag) 대신에 도전성 페이스트 내의 함량을 증가시키더라도 변환효율이 크게 떨어지지 않음을 표1과 같이 확인할 수 있다.3 and 4, the bus bar is formed in the longitudinal direction of the solar cell and is a passage through which electrons move. Conventionally, silver (Ag) is uniformly distributed when fired with a pleat containing silver (Ag) and lead (Pb) components. In the solar cell according to the embodiment of the present invention, silver (Ag) and the conductive glass frit are fired to form a bus bar as shown in FIGS. 3 and 4, and in this case, the conductive glass frit is formed on both sides of the bus bar as shown in FIG. 4. It is formed and it can confirm that silver (Ag) is gathered and formed in the center. Silver (Ag) is gathered at the center of the busbar to improve conductivity (conductivity improves compared to when silver (Ag) was uniformly dispersed), and the conductive glass frit also has conductivity as the name suggests. Increasing the content in the conductive paste instead of (Ag) it can be confirmed that the conversion efficiency is not significantly reduced as shown in Table 1.
여기서 소성가공을 위한 소성온도는 400℃ 내지 600℃일 수 있다.Here, the firing temperature for the plastic working may be 400 ℃ to 600 ℃.
도전성 유리프릿은 바나듐(V), 바륨(Ba) 및 철(Fe)을 함유한 바나듐산유리를 포함한다. 특히 철은 내부적으로 강하게 결합하여 해당 내부에 머물고 있어, 다른 재료와 혼합해도 그 결합성은 지극히 작은 성질을 갖는다.The conductive glass frit includes vanadium glass containing vanadium (V), barium (Ba) and iron (Fe). In particular, iron is strongly bonded internally and stays therein, and even when mixed with other materials, the bonding property is extremely small.
이처럼 도전성을 가지는 유리프릿을 사용함으로써, 표 1과 같은 변환 효율을 갖는 것은 유리프릿이 도전성을 갖는다는 점, 도전성 페이스트에 포함되어 있는 은을 유리로부터 분리해 도전성이 개선된다는 점, 유리의 침상결정의 성장을 억제해 은(Ag)에 의한 도전성이 개선된다는 점, 버스바 전극형성에 이용하는 도전성 유리프릿은 파이어링 현상이 일어나지 않아 변환효율의 저감이 발생하지 않는다는 점 때문이다.By using the conductive glass frit as described above, the conversion efficiency shown in Table 1 is that the glass frit has conductivity, the silver contained in the conductive paste is separated from the glass, and the conductivity is improved. This is because the conductivity of silver (Ag) is improved by suppressing the growth of, and the conductive glass frit used to form the busbar electrode does not cause a firing phenomenon and thus a reduction in conversion efficiency does not occur.
이상 본 발명의 실시예에 따른 태양전지에 대해서 살펴보았다. 이하 본 발명의 또 다른 양태인 태양전지의 제조방법에 대해서 도 5 내지 도 6을 통해 살펴본다.The solar cell according to the embodiment of the present invention has been described above. Hereinafter, a method of manufacturing a solar cell, which is another embodiment of the present invention, will be described with reference to FIGS. 5 to 6.
앞선 실시예와 중복되는 구성에 대한 설명은 생략한다.The description of the overlapping configuration with the foregoing embodiment will be omitted.
도 5는 본 발명의 실시예에 따른 태양전지 제조방법의 순서도이다.5 is a flow chart of a solar cell manufacturing method according to an embodiment of the present invention.
도 6은 본 발명의 실시예에 따른 태양전지 공정설명도이다.6 is a solar cell process description according to an embodiment of the present invention.
도 5와 도 6에 도시된 바와 같이 본 발명의 실시예에 따른 태양전지 제조방법은 기판을 준비하는 단계(S100), 상기 기판에 확산도핑층을 형성하는 단계(S200), 상기 확산도핑층 상부에 절연층을 형성하는 단계(S300), 상기 절연층 상부에 핑거전극을 형성하는 단계(S400), 상기 핑거전극이 절연층을 관통하도록 제1소성가공하는 단계(S500), 상기 절연층 상부에 도전성 유리프릿(glass frit)을 함유한 도전성 페이스트를 이용하여 버스바를 형성하는 단계(S600), 상기 핑거전극과 버스바가 접촉연결되도록 제2소성가공하는 단계(S700) 및 상기 기판의 하부에 후면 전극을 형성하는 단계(S800)를 포함한다.5 and 6, in the solar cell manufacturing method according to the embodiment of the present invention, preparing a substrate (S100), forming a diffusion doping layer on the substrate (S200), the diffusion doping layer upper Forming an insulating layer on the insulating layer (S300), forming a finger electrode on the insulating layer (S400), and performing a first firing process on the finger electrode to penetrate the insulating layer (S500). Forming a bus bar using a conductive paste containing a conductive glass frit (S600), performing a second baking process such that the finger electrode and the bus bar are in contact with each other (S700), and a rear electrode on the bottom of the substrate. Forming step (S800).
또한 본 발명의 실시예에 따른 태양전지 제조방법은 상기 버스바 상부에 리드전극을 형성하는 단계(S900)를 더 포함한다.In addition, the solar cell manufacturing method according to an embodiment of the present invention further comprises the step of forming a lead electrode on the bus bar (S900).
기판(100)을 준비하는 단계(S100)는 반도체 실리콘 기판을 준비하고 이를 세척하는 단계를 더 포함할 수 있다.Preparing the substrate 100 (S100) may further include preparing a semiconductor silicon substrate and cleaning the same.
기판(100)에 확산도핑층(200)을 형성하는 단계(S200)는 불순물을 도핑하여 고전자 농도영역을 기판상에 형성한다. 확산도핑층(200)은 태양광이 입사하여 전자를 버스바로 이동하도록 한다.In the step S200 of forming the diffusion doping layer 200 on the substrate 100, a high electron concentration region is formed on the substrate by doping impurities. The diffusion doped layer 200 allows sunlight to enter and move electrons to the busbar.
확산 도핑층(200) 상부에 절연층(300)을 형성하는 단계(S300)는 확산 도핑층(200)과 버스바(400)를 분리시키기 위한 절연층(300)을 형성한다. 절연층(300)은 질화실리콘막일 수 있으며, 반사방지막 기능을 함께 수행할 수 있다.In the step S300 of forming the insulating layer 300 on the diffusion doped layer 200, the insulating layer 300 for separating the diffusion doped layer 200 and the bus bar 400 is formed. The insulating layer 300 may be a silicon nitride film and may also function as an anti-reflection film.
절연층(300) 상부에 핑거전극(500)을 형성하는 단계(S400)는 절연층(300) 상부에 핑거전극(500)을 스크린 인쇄한다. 인쇄재료로는 은(Ag)에 프릿으로서 납유리를 혼합한 것을 사용할 수 있으나 반드시 이에 제한되는 것은 아니다.In the forming of the finger electrode 500 on the insulating layer 300 (S400), the finger electrode 500 is screen printed on the insulating layer 300. As a printing material, a mixture of lead glass as silver and frit may be used, but is not necessarily limited thereto.
핑거전극(500)을 형성한 다음 핑거전극(500)이 절연층(300)을 관통하도록 제1소성가공하는 단계(S500)는 스크린 인쇄한 핑거전극(500)의 패턴(은과 납유리 플리트의 혼입물)을 고온에서 소성하여 절연층(질화실리콘막)(300)에 파이어 스루시켜 핑거전극(500)이 절연층(300)을 관통하도록 한다. 핑거전극(500)은 확산 도핑층(200)과 연결되어 확산 도핑층(200)에서 전자가 이동하는 통로가 된다.After forming the finger electrode 500 and performing a first firing process so that the finger electrode 500 penetrates the insulating layer 300, the pattern of the screen-printed finger electrode 500 (mixing of silver and lead glass pleats) is performed. Water) is fired at a high temperature to fire through the insulating layer (silicon nitride film) 300 so that the finger electrode 500 penetrates the insulating layer 300. The finger electrode 500 is connected to the diffusion doping layer 200 to become a passage through which electrons move in the diffusion doping layer 200.
제1소성가공은 100℃ 내지 200℃ 온도로 약 20초 내지 1분간 가열하여 핑거전극(500)을 가공한다.The first firing is heated at a temperature of 100 ° C. to 200 ° C. for about 20 seconds to 1 minute to process the finger electrode 500.
절연층(300) 상부에 도전성 유리프릿(glass frit)을 함유한 도전성 페이스트를 이용하여 버스바(400)를 형성하는 단계(S600)는 절연층(300) 상부에 핑거전극(500)과 연결되도록 버스바(400)를 스크린 인쇄를 통해서 형성한다. 버스바(400)는 도전성 페이스트를 이용하되, 도전성 페이스트는 도전성 유리프릿을 포함하고 있다.The step S600 of forming the bus bar 400 using the conductive paste containing the conductive glass frit on the insulating layer 300 may be connected to the finger electrode 500 on the insulating layer 300. The busbar 400 is formed through screen printing. The bus bar 400 uses a conductive paste, but the conductive paste includes a conductive glass frit.
특히, 도전성 페이스트는 20wt% 내지 70wt%의 도전성 유리프릿을 포함하고, 도전성 유리프릿은 바나듐(V), 바륨(Ba) 및 철(Fe) 등으로 이루어져 있다.In particular, the conductive paste includes 20 wt% to 70 wt% of conductive glass frit, and the conductive glass frit is made of vanadium (V), barium (Ba), iron (Fe), and the like.
도전성 페이스트는 일반적으로 은(Ag)을 함유하고 있으며, 구리(Cu)를 함유할 수도 있으나 구리(Cu)는 산화가 잘 일어나 전극으로서의 효율이 쉽게 떨어지는 문제가 있다.The conductive paste generally contains silver (Ag) and may contain copper (Cu), but copper (Cu) is easily oxidized, which causes a problem of poor efficiency as an electrode.
핑거전극(500)과 버스바(400)가 접촉연결되도록 제2소성가공하는 단계(S700)는 스크린 인쇄한 버스바(400)의 패턴을 가열하여 제2소성가공하되, 소성시간은 1분이내 2초 ~ 3초이상으로 가열할 수 있으며, 소성온도는 약 400℃ 내지 600℃일 수 있다.In the second firing process such that the finger electrode 500 and the bus bar 400 are in contact with each other (S700), the second baking process is performed by heating the pattern of the screen-printed bus bar 400, but the firing time is within 2 minutes. Second to 3 seconds or more can be heated, the firing temperature may be about 400 ℃ to 600 ℃.
제2소성가공이 완료되면 버스바의 양측에 도전성 유리프릿, 특히 바륨 성분이 입자상으로 형성되고, 중앙부분에 은(Ag)이 모이게 된다. 또한, 도전성 유리프릿도 전자가 이동할 수 있는 전도성을 가지므로 은(Ag)의 함량을 줄이더라도 태양전지의 전체적인 변환효율은 크게 변하지 않는다. 또한, 도전성 유리프릿에는 납(Pb)성분이 포함되어 있지 않아 환경오염의 우려가 전혀 없다.When the second firing process is completed, conductive glass frits, particularly barium, are formed in the form of particles on both sides of the bus bar, and silver (Ag) is collected at the center portion. In addition, since the conductive glass frit also has conductivity to move electrons, even if the content of silver (Ag) is reduced, the overall conversion efficiency of the solar cell does not change significantly. In addition, since the lead glass (Pb) is not contained in the conductive glass frit, there is no fear of environmental pollution.
기판(100)의 하부에 후면전극(700)을 형성하는 단계(S800)는 기판(100)에 태양광이 입사하는 면의 반대면에 도전성 후면전극(700)을 형성하는 과정이다. 전극을 형성하는 과정은 반도체 공정상에 전극을 형성하는 일반적인 방법을 사용하므로 상세한 설명은 생략한다.The step S800 of forming the back electrode 700 under the substrate 100 is a process of forming the conductive back electrode 700 on a surface opposite to the surface where the solar light is incident on the substrate 100. The process of forming the electrode uses a general method of forming the electrode on the semiconductor process, so a detailed description thereof will be omitted.
버스바(400) 상부에 리드전극(600)을 형성하는 단계(S900)는 버스바(400)를 전기적으로 접속하는 리드전극(600)을 형성하여 버스바(400)에 있는 전자들이 이동할 수 있도록 한다.The step S900 of forming the lead electrode 600 on the bus bar 400 forms a lead electrode 600 that electrically connects the bus bar 400 so that the electrons in the bus bar 400 can move. do.
이상과 같은 제조방법을 이용하여 제조된 태양전지는 분말형태의 도전성 유리프릿과 은(Ag)분말을 유기용매와 섞어 제조된 도전성 페이스트를 기판상에 스크린 인쇄하여 구비되는 버스바(400)를 이용함으로써, 도전성 유리프릿이라는 특성상 은(Ag)의 함량을 줄일 수 있으며, 도전성 유리프릿에는 납(Pb)성분이 함유되어 있지 않아 환경오염의 위험이 없는 태양전지의 제조가 가능하다.The solar cell manufactured using the manufacturing method described above uses a bus bar 400 provided by screen printing a conductive paste prepared by mixing a conductive glass frit and silver (Ag) powder in an organic solvent with an organic solvent. As a result, the content of silver (Ag) can be reduced due to the property of the conductive glass frit, and the conductive glass frit does not contain lead (Pb), which makes it possible to manufacture solar cells without the risk of environmental pollution.

Claims (9)

  1. 기판;Board;
    상기 기판상에 형성되는 확산도핑층; 및A diffusion doping layer formed on the substrate; And
    상기 확산도핑층 상에 형성되는 절연층을 포함하는 태양전지로서,A solar cell comprising an insulating layer formed on the diffusion doped layer,
    상기 절연층 상에 형성되는 버스바(busbar)를 포함하고, 상기 확산도핑층과A busbar formed on the insulating layer, the diffusion doped layer and
    상기 버스바가 연결되도록 상기 절연층의 소정영역을 관통하여 형성되는 핑거전극을 포함하되, 상기 버스바는 도전성 유리프릿(glass frit)을 함유한 도전성 페이스트를 이용하여 형성되는 것을 특징으로 하는 태양전지.And a finger electrode formed through a predetermined region of the insulating layer so that the bus bars are connected, wherein the bus bars are formed using a conductive paste containing a conductive glass frit.
  2. 제1항에 있어서,The method of claim 1,
    상기 도전성 페이스트는 20wt% 내지 70wt%의 도전성 유리프릿을 포함하는 것을 특징으로 하는 태양전지.The conductive paste is a solar cell, characterized in that it comprises a conductive glass frit of 20wt% to 70wt%.
  3. 제2항에 있어서,The method of claim 2,
    상기 도전성 유리프릿은 바나듐(V), 바륨(Ba) 및 철(Fe)을 함유한 바나듐산유리를 포함하는 것을 특징으로 하는 태양전지.The conductive glass frit comprises a vanadium glass containing vanadium (V), barium (Ba) and iron (Fe).
  4. 제1항에 있어서,The method of claim 1,
    상기 버스바 상에 리드전극을 더 포함하는 것을 특징으로 하는 태양전지.The solar cell further comprises a lead electrode on the bus bar.
  5. 제1항에 있어서,The method of claim 1,
    상기 기판의 하부에 후면전극을 더 포함하는 것을 특징으로 하는 태양전지.The solar cell further comprises a rear electrode under the substrate.
  6. (a) 기판을 준비하는 단계;(a) preparing a substrate;
    (b) 상기 기판에 확산도핑층을 형성하는 단계;(b) forming a diffusion doping layer on the substrate;
    (c) 상기 확산도핑층 상부에 절연층을 형성하는 단계;(c) forming an insulating layer on the diffusion doped layer;
    (d) 상기 절연층 상부에 핑거전극을 형성하는 단계;(d) forming a finger electrode on the insulating layer;
    (e) 상기 핑거전극이 절연층을 관통하도록 제1소성가공하는 단계;(e) first firing the finger electrode through the insulating layer;
    (f) 상기 절연층 상부에 도전성 유리프릿(glass frit)을 함유한 도전성 페이스트를 이용하여 버스바를 형성하는 단계;(f) forming a bus bar using a conductive paste containing a conductive glass frit on the insulating layer;
    (g) 상기 핑거전극과 버스바가 접촉연결되도록 제2소성가공하는 단계; 및(g) performing a second firing process such that the finger electrode and the bus bar are in contact with each other; And
    (h) 상기 기판의 하부에 후면전극을 형성하는 단계를 포함하는 것을 특징으로 하는 태양전지 제조방법.(h) forming a back electrode on the lower portion of the substrate.
  7. 제6항에 있어서,The method of claim 6,
    상기 (g)단계 이후에 상기 버스바 상부에 리드전극을 형성하는 단계를 더 포함하는 것을 특징으로 하는 태양전지 제조방법.After the step (g) further comprising the step of forming a lead electrode on the upper bus bar.
  8. 제6항에 있어서,The method of claim 6,
    상기 도전성 페이스트는 20wt% 내지 70wt%의 도전성 유리프릿 포함하는 것을 특징으로 하는 태양전지 제조방법.The conductive paste is a solar cell manufacturing method characterized in that it comprises 20wt% to 70wt% conductive glass frit.
  9. 제6항에 있어서,The method of claim 6,
    상기 도전성 유리프릿은 바나듐(V), 바륨(Ba) 및 철(Fe)을 포함하는 것을 특징으로 하는 태양전지 제조방법.The conductive glass frit comprises a vanadium (V), barium (Ba) and iron (Fe) manufacturing method of a solar cell.
PCT/KR2016/012272 2016-05-25 2016-10-28 Solar cell and manufacturing method therefor WO2017204422A1 (en)

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