WO2013042965A1 - Solar cell - Google Patents

Solar cell Download PDF

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Publication number
WO2013042965A1
WO2013042965A1 PCT/KR2012/007556 KR2012007556W WO2013042965A1 WO 2013042965 A1 WO2013042965 A1 WO 2013042965A1 KR 2012007556 W KR2012007556 W KR 2012007556W WO 2013042965 A1 WO2013042965 A1 WO 2013042965A1
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WO
WIPO (PCT)
Prior art keywords
solar cell
support substrate
concave portion
concave
concave part
Prior art date
Application number
PCT/KR2012/007556
Other languages
French (fr)
Inventor
Myoung Seok Sung
Original Assignee
Lg Innotek Co., Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from KR1020110094488A external-priority patent/KR20130030905A/en
Priority claimed from KR1020110094489A external-priority patent/KR20130030906A/en
Application filed by Lg Innotek Co., Ltd. filed Critical Lg Innotek Co., Ltd.
Publication of WO2013042965A1 publication Critical patent/WO2013042965A1/en

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    • 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
    • H01L31/052—Cooling means directly associated or integrated with the PV cell, e.g. integrated Peltier elements for active cooling or heat sinks directly associated with the PV cells
    • 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
    • H01L31/0248—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 characterised by their semiconductor bodies
    • H01L31/036—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 characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes
    • H01L31/0392—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 characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes including thin films deposited on metallic or insulating substrates ; characterised by specific substrate materials or substrate features or by the presence of intermediate layers, e.g. barrier layers, on the substrate
    • 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
    • H01L31/0248—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 characterised by their semiconductor bodies
    • H01L31/036—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 characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes
    • H01L31/0392—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 characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes including thin films deposited on metallic or insulating substrates ; characterised by specific substrate materials or substrate features or by the presence of intermediate layers, e.g. barrier layers, on the substrate
    • H01L31/03923—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 characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes including thin films deposited on metallic or insulating substrates ; characterised by specific substrate materials or substrate features or by the presence of intermediate layers, e.g. barrier layers, on the substrate including AIBIIICVI compound materials, e.g. CIS, CIGS
    • 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
    • H01L31/0248—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 characterised by their semiconductor bodies
    • H01L31/036—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 characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes
    • H01L31/0392—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 characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes including thin films deposited on metallic or insulating substrates ; characterised by specific substrate materials or substrate features or by the presence of intermediate layers, e.g. barrier layers, on the substrate
    • H01L31/03925—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 characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes including thin films deposited on metallic or insulating substrates ; characterised by specific substrate materials or substrate features or by the presence of intermediate layers, e.g. barrier layers, on the substrate including AIIBVI compound materials, e.g. CdTe, CdS
    • 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
    • Y02E10/541—CuInSe2 material PV cells

Definitions

  • the disclosure relates to a solar cell.
  • a method of fabricating a solar cell for solar light power generation is as follows. First, after preparing a substrate, a back electrode layer is formed on the substrate and patterned by a laser, thereby forming a plurality of back electrodes.
  • a light absorbing layer, a buffer layer, and a high resistance buffer layer are sequentially formed on the back electrodes.
  • Various schemes such as a scheme of forming a Cu(In,Ga)Se2 (CIGS) based-light absorbing layer by simultaneously or separately evaporating Cu, In, Ga, and Se and a scheme of performing a selenization process after a metallic precursor film has been formed, have been extensively used in order to form the light absorbing layer.
  • the energy band gap of the light absorbing layer is in the range of about 1eV to about 1.8eV.
  • a buffer layer including cadmium sulfide (CdS) is formed on the light absorbing layer through a sputtering process.
  • the energy bandgap of the buffer layer may be in the range of about 2.2eV to about 2.4eV.
  • a high resistance buffer layer including zinc oxide (ZnO) is formed on the buffer layer through the sputtering process.
  • the energy bandgap of the high resistance buffer layer is in the range of about 3.1eV to about 3.3eV.
  • a groove pattern may be formed in the light absorbing layer, the buffer layer, and the high resistance buffer layer.
  • a transparent conductive material is laminated on the high resistance buffer layer, and is filled in the groove pattern. Therefore, a transparent electrode layer is formed on the high resistance buffer layer, and connection wires are formed in the groove pattern.
  • a material constituting the transparent electrode layer and the connection wireless may include aluminum doped zinc oxide (AZO).
  • the energy bandgap of the transparent electrode layer may be in the range of about 3.1eV to about 3.3eV.
  • the groove pattern is formed in the transparent electrode layer, so that a plurality of solar cells may be formed.
  • the transparent electrodes and the high resistance buffers correspond to the cells, respectively.
  • the transparent electrodes and the high resistance buffers may be provided in the form of a stripe or a matrix.
  • the transparent electrodes and the back electrodes are misaligned from each other and electrically connected with each other through the connection wires. Accordingly, the solar cells may be electrically connected to each other in series.
  • the embodiment provides a solar cell capable of representing improved photoelectric conversion efficiency.
  • the solar cell includes a support substrate including a concave part; and a light absorbing layer, a buffer layer, and a front electrode layer on the support substrate.
  • a solar cell includes a support substrate including a concave part; a light absorbing layer, a buffer layer, and a front electrode layer on the support substrate; and a heat dissipating part in the concave part.
  • the solar cell according to the embodiment includes a concave part in a back surface of a support substrate.
  • a sectional area of the back surface of the support substrate is increased due to the concave part so that heat can be efficiently dissipated from the central area and heat concentration at the central area can be prevented. Accordingly, loss of power due to heat can be prevented, and efficiency reduction due to increase of the temperature in a local surface caused by solar light can be prevented.
  • stiffness of the support substrate is reinforced due to the concave part so that bending and sagging due to gravity may be prevented in a large-size thin film solar cell. Accordingly, a high-efficiency solar cell can be provided.
  • the heat dissipation part is provided in the concave part.
  • the heat dissipation part may include metal or metal oxide having high electrical conductivity so that heat can be rapidly dissipated from the support substrate.
  • FIG. 1 is a sectional view showing a solar cell according to the embodiment
  • FIG. 2 is a plan view showing a support substrate included in the solar cell according to a first embodiment
  • FIG. 3 is a plan view showing a support substrate included in the solar cell according to a second embodiment
  • FIG. 4 is a plan view showing a support substrate included in the solar cell according to a third embodiment.
  • FIG. 5 is a sectional view showing a solar cell according to a fourth embodiment.
  • FIG. 1 is a sectional view showing a solar cell according to the embodiment.
  • FIG. 2 is a plan view showing a support substrate included in the solar cell according to a first embodiment.
  • the solar cell 100 includes a support substrate 100 having a concave part 120, a back electrode layer 200, a light absorbing layer 300, a buffer layer 400, a high resistance buffer layer 500, and a front electrode layer 600.
  • the support substrate 100 has a plate shape and supports the back electrode layer 200, the light absorbing layer 300, the buffer layer 400, the high-resistance buffer layer 500, and the nano-alloy protrusions 600.
  • the support substrate 100 may be an insulator.
  • the support substrate 100 may be a glass substrate, a plastic substrate or a metal substrate.
  • the support substrate 100 may be a soda lime glass substrate.
  • the support substrate 100 may be rigid or flexible.
  • the support substrate 100 may include a concave part 120. At least one concave part 120 may be provided on the support substrate 100.
  • the support substrate 100 has a first surface 100a (hereinafter referred to as ‘top surface 100a’) and a second surface 100b (hereinafter referred to as ‘back surface 100b’) opposite to each other.
  • the light absorbing layer 300, the buffer layer 400, and the front electrode layer 600 may be formed on the top surface 100a of the support substrate 100 and the concave part 120 may be provided on the back surface 100b of the support substrate 100.
  • a plurality of concave parts 120 may be provided on the back surface 100b of the support substrate 100.
  • the concave part 120 may include a first concave part 121 and a second concave part 122.
  • the first concave part 121 and the second concave part 122 may be provided in different locations of the support substrate 100.
  • the first concave portion 121 may extend in the first direction of the support substrate 100 and the second concave portion 122 may extend in the second direction crossing the first direction of the support substrate 100. Accordingly, as shown in FIG. 2, the concave portion 120 may have a stripe pattern.
  • the support substrate 100 may include a central area CA and an edge area EA surrounding the central area CA, and the concave part 120 may be provided in the central area CA and the edge area EA.
  • the concave part 120 provided in the central area CA may have a width different from a width of the concave part 120 provided in the edge area EA.
  • the concave part 120 formed in the central area CA may have a width wider than that of the concave part 120 formed in the edge area EA.
  • a sectional area of a back surface 100b of the support substrate 100 is increased due to the concave part 120 so that heat can be efficiently dissipated from the central area CA and heat concentration at the central area CA can be prevented. Accordingly, loss of power due to heat can be prevented, and efficiency reduction due to the temperature increase in a local surface caused by solar light can be prevented.
  • stiffness of the support substrate 100 is increased due to the concave part 120 so that bending and sagging due to gravity may be prevented in a large-size thin film solar cell. Accordingly, high-efficiency solar cell can be provided.
  • An area of the concave portion 120 may be in the range of 10% to 20% based on an area of the support substrate 100.
  • a depth of the concave portion 120 may be in the range of 20% to 80% based on a thickness of the support substrate 100.
  • the depth of the concave part 120 is less than 20% based on the thickness of the support substrate 100, effect of heat dissipation may be weak.
  • the depth of the concave part 120 exceeds 80% based on the thickness of the support substrate 100, a physical strength of the support substrate 100 may become weak.
  • the back electrode layer 200 is provided on the top surface 100a of the support substrate 100.
  • the back electrode layer 200 is a conductive layer.
  • a material used for the back electrode layer 200 may include metal such as molybdenum (Mo).
  • the back electrode layer 200 may include two or more layers.
  • the layers may be formed by the same metal or different metals.
  • the light absorbing layer 300 is provided on the back electrode layer 200.
  • the light absorbing layer 300 includes a group I-III-VI compound.
  • the light absorbing layer 300 may have the CIGSS (Cu(IN,Ga)(Se,S)2) crystal structure, the CISS (Cu(IN)(Se,S)2) crystal structure or the CGSS (Cu(Ga)(Se,S)2) crystal structure.
  • the energy bandgap of the light absorbing layer 300 may be in the range of about 1eV to about 1.8eV.
  • the buffer layer 400 is provided on the light absorbing layer 300.
  • the buffer layer 400 directly makes contact with the light absorbing layer 300.
  • the buffer layer 400 includes cadmium sulfide (CdS).
  • the energy bandgap of the buffer layer 400 may be in the range of about 1.9eV to about 2.3eV.
  • the high resistance buffer layer 500 is provided on the buffer layer 400.
  • the high resistance buffer layer 500 includes i-ZnO which is not doped with impurities.
  • the energy bandgap of the high resistance buffer layer 500 may be in the range of about 3.1eV to about 3.3eV.
  • the front electrode layer 600 is provided on the light absorbing layer 300.
  • the front electrode layer 600 is provided on the high resistance buffer layer 500.
  • the front electrode layer 600 is provided on the high resistance buffer layer 500.
  • the front electrode layer 600 may be transparent.
  • a material used for the front electrode layer 600 may include an Al doped zinc oxide (AZO), an indium zinc oxide (IZO), or an indium tin oxide (ITO).
  • the front electrode layer 600 may have a thickness in the range of about 500nm to about 1.5 ⁇ m.
  • the front electrode layer 600 is formed by the Al doped zinc oxide (AZO), aluminum (Al) may be doped at the rate of about 2.5wt% to about 3.5wt%.
  • the front electrode layer 600 is a conductive layer.
  • FIG. 3 is a plan view showing a support substrate 100 included in the solar cell according to a second embodiment.
  • a concave portion 120 may be provided in a back surface 100b of a support substrate 100 included in the solar cell according to the embodiment.
  • the concave part 120 may include a first concave portion 121 and a second concave portion 122.
  • the second concave portion 122 may be spaced apart from the first concave portion 121.
  • the first concave portion 121 and the second concave portion 122 may extend along each side of the support substrate 100.
  • the concave part 120 may form a circle on the support substrate 100. That is, the first concave part 121 may form a circle in the central area CA of the support substrate 100 and the second concave part 122 may form a circle in the edge area EA of the support substrate 100.
  • a width of the first concave part 121 may be larger than a width of the second concave part 122.
  • heat may be efficiently dissipated from the central area CA of the support substrate 100.
  • FIG. 4 is a plan view showing a support substrate 100 included in the solar cell according to a third embodiment.
  • the support substrate 100 included in the solar cell according to the third embodiment includes concave parts 120.
  • the support substrate 100 includes a central area CA and an edge area EA surrounding the central area CA.
  • the concave parts 120 may radially extend from the central area CA to the edge area EA. Therefore, the concave parts 120 are concentrated in the central area CA and gradually dispersed in the direction of the edge area EA. Accordingly, heat may be efficiently dissipated from the central area CA.
  • the concave parts 120 may be formed with various patterns for heat dissipation of the support substrate 100.
  • FIG. 5 is a sectional view showing a solar cell according to a fourth embodiment.
  • the solar cell 200 includes a support substrate 100 having a concave part 120, a heat dissipating part 140, a back electrode layer 200, a light absorbing layer 300, a buffer layer 400, a high resistance buffer layer 500, and a front electrode layer 600.
  • the support substrate 100 has a first surface 100a (hereinafter referred to as ‘top surface 100a’) and a second surface 100b (hereinafter referred to as ‘back surface 100b’) opposite each other.
  • the light absorbing layer 300 and the buffer layer 400, and the front electrode layer 600 may be provided on the top surface 100a and the concave part 120 may be provided on the back surface 100b.
  • the heat dissipating part 140 may be provided in the concave part 120.
  • the heat dissipating part 140 includes a first heat dissipating portion 141 and a second heat dissipating portion 142.
  • the heat dissipating part 140 may include the first heat dissipating portion 141 filled in the concave part 120 and the second heat dissipating portion 142 exposed on the support substrate 100.
  • the heat dissipating part 140 may include metal.
  • the heat dissipating part 140 may include at least one selected from the group consisting of metal including copper (Cu), aluminum (Al), silver (Ag), nickel (Ni), and chromium (Cr), and oxide having the metal.
  • the heat dissipation part 140 may include metal or metal oxide having high electrical conductivity to rapidly discharge heat of the support substrate 100.
  • the heat dissipating part 140 may be provided by inserting paste including the metal and metal oxide into the concave part 120 or coating the paste on the back surface 100b of the support substrate 100.
  • the paste including the copper (Cu) or the aluminum (Al) may be easily inserted into the concave part due to the flexibility thereof.
  • a thickness t of the second heat dissipating part 142 may be in the range of 20% to 40% based on a depth of the concave part 120.
  • the heat dissipating part 140 may be provided in the back surface 100b of the support substrate 100 to rapidly dissipate heat of the support substrate 100, thereby reducing the concentration of the heat.
  • any reference in this specification to “one embodiment,” “an embodiment,” “example embodiment,” etc. means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention.
  • the appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment.

Abstract

A solar cell according to an embodiment includes a support substrate including a concave part; and a light absorbing layer, a buffer layer, and a front electrode layer on the support substrate.

Description

SOLAR CELL
The disclosure relates to a solar cell.
A method of fabricating a solar cell for solar light power generation is as follows. First, after preparing a substrate, a back electrode layer is formed on the substrate and patterned by a laser, thereby forming a plurality of back electrodes.
Thereafter, a light absorbing layer, a buffer layer, and a high resistance buffer layer are sequentially formed on the back electrodes. Various schemes, such as a scheme of forming a Cu(In,Ga)Se2 (CIGS) based-light absorbing layer by simultaneously or separately evaporating Cu, In, Ga, and Se and a scheme of performing a selenization process after a metallic precursor film has been formed, have been extensively used in order to form the light absorbing layer. The energy band gap of the light absorbing layer is in the range of about 1eV to about 1.8eV.
Then, a buffer layer including cadmium sulfide (CdS) is formed on the light absorbing layer through a sputtering process. The energy bandgap of the buffer layer may be in the range of about 2.2eV to about 2.4eV. After that, a high resistance buffer layer including zinc oxide (ZnO) is formed on the buffer layer through the sputtering process. The energy bandgap of the high resistance buffer layer is in the range of about 3.1eV to about 3.3eV.
Thereafter, a groove pattern may be formed in the light absorbing layer, the buffer layer, and the high resistance buffer layer.
After that, a transparent conductive material is laminated on the high resistance buffer layer, and is filled in the groove pattern. Therefore, a transparent electrode layer is formed on the high resistance buffer layer, and connection wires are formed in the groove pattern. A material constituting the transparent electrode layer and the connection wireless may include aluminum doped zinc oxide (AZO). The energy bandgap of the transparent electrode layer may be in the range of about 3.1eV to about 3.3eV.
Then, the groove pattern is formed in the transparent electrode layer, so that a plurality of solar cells may be formed. The transparent electrodes and the high resistance buffers correspond to the cells, respectively. The transparent electrodes and the high resistance buffers may be provided in the form of a stripe or a matrix.
The transparent electrodes and the back electrodes are misaligned from each other and electrically connected with each other through the connection wires. Accordingly, the solar cells may be electrically connected to each other in series.
As described above, in order to convert the solar light into electrical energy, various solar cell apparatuses have been fabricated and used. One of the solar cell apparatuses is disclosed in Korean Unexamined Patent Publication No. 10-2008-0088744.
The embodiment provides a solar cell capable of representing improved photoelectric conversion efficiency.
According to the embodiment, the solar cell includes a support substrate including a concave part; and a light absorbing layer, a buffer layer, and a front electrode layer on the support substrate.
A solar cell according to the embodiment includes a support substrate including a concave part; a light absorbing layer, a buffer layer, and a front electrode layer on the support substrate; and a heat dissipating part in the concave part.
The solar cell according to the embodiment includes a concave part in a back surface of a support substrate. A sectional area of the back surface of the support substrate is increased due to the concave part so that heat can be efficiently dissipated from the central area and heat concentration at the central area can be prevented. Accordingly, loss of power due to heat can be prevented, and efficiency reduction due to increase of the temperature in a local surface caused by solar light can be prevented.
Further, stiffness of the support substrate is reinforced due to the concave part so that bending and sagging due to gravity may be prevented in a large-size thin film solar cell. Accordingly, a high-efficiency solar cell can be provided.
Meanwhile, in the solar cell according to another embodiment, the heat dissipation part is provided in the concave part. The heat dissipation part may include metal or metal oxide having high electrical conductivity so that heat can be rapidly dissipated from the support substrate.
FIG. 1 is a sectional view showing a solar cell according to the embodiment;
FIG. 2 is a plan view showing a support substrate included in the solar cell according to a first embodiment;
FIG. 3 is a plan view showing a support substrate included in the solar cell according to a second embodiment;
FIG. 4 is a plan view showing a support substrate included in the solar cell according to a third embodiment; and
FIG. 5 is a sectional view showing a solar cell according to a fourth embodiment.
In the description of the embodiments, it will be understood that when a substrate, a layer, a film or an electrode is referred to as being “on” or “under” another substrate, another layer, another film or another electrode, it can be “directly” or “indirectly” on the other substrate, the other layer, the other film, or the other electrode, or one or more intervening layers may also be present. Such a position of the layer has been described with reference to the drawings.
The size of the elements shown in the drawings may be exaggerated for the purpose of explanation and may not utterly reflect the actual size.
Hereinafter, embodiments will be described below in more detail with reference to the accompanying drawings.
First, a solar cell will be described in detail with reference to FIGS. 1 and 2. FIG. 1 is a sectional view showing a solar cell according to the embodiment. FIG. 2 is a plan view showing a support substrate included in the solar cell according to a first embodiment.
Referring to FIG. 1, the solar cell 100 according to the first embodiment includes a support substrate 100 having a concave part 120, a back electrode layer 200, a light absorbing layer 300, a buffer layer 400, a high resistance buffer layer 500, and a front electrode layer 600.
The support substrate 100 has a plate shape and supports the back electrode layer 200, the light absorbing layer 300, the buffer layer 400, the high-resistance buffer layer 500, and the nano-alloy protrusions 600.
The support substrate 100 may be an insulator. The support substrate 100 may be a glass substrate, a plastic substrate or a metal substrate. In detail, the support substrate 100 may be a soda lime glass substrate. The support substrate 100 may be rigid or flexible.
The support substrate 100 may include a concave part 120. At least one concave part 120 may be provided on the support substrate 100.
The support substrate 100 has a first surface 100a (hereinafter referred to as ‘top surface 100a’) and a second surface 100b (hereinafter referred to as ‘back surface 100b’) opposite to each other. The light absorbing layer 300, the buffer layer 400, and the front electrode layer 600 may be formed on the top surface 100a of the support substrate 100 and the concave part 120 may be provided on the back surface 100b of the support substrate 100.
In detail, referring to FIG. 2, a plurality of concave parts 120 may be provided on the back surface 100b of the support substrate 100. The concave part 120 may include a first concave part 121 and a second concave part 122. The first concave part 121 and the second concave part 122 may be provided in different locations of the support substrate 100. In detail, the first concave portion 121 may extend in the first direction of the support substrate 100 and the second concave portion 122 may extend in the second direction crossing the first direction of the support substrate 100. Accordingly, as shown in FIG. 2, the concave portion 120 may have a stripe pattern.
The support substrate 100 may include a central area CA and an edge area EA surrounding the central area CA, and the concave part 120 may be provided in the central area CA and the edge area EA. In this case, the concave part 120 provided in the central area CA may have a width different from a width of the concave part 120 provided in the edge area EA. In detail, the concave part 120 formed in the central area CA may have a width wider than that of the concave part 120 formed in the edge area EA.
A sectional area of a back surface 100b of the support substrate 100 is increased due to the concave part 120 so that heat can be efficiently dissipated from the central area CA and heat concentration at the central area CA can be prevented. Accordingly, loss of power due to heat can be prevented, and efficiency reduction due to the temperature increase in a local surface caused by solar light can be prevented.
Further, stiffness of the support substrate 100 is increased due to the concave part 120 so that bending and sagging due to gravity may be prevented in a large-size thin film solar cell. Accordingly, high-efficiency solar cell can be provided.
An area of the concave portion 120 may be in the range of 10% to 20% based on an area of the support substrate 100.
A depth of the concave portion 120 may be in the range of 20% to 80% based on a thickness of the support substrate 100. When the depth of the concave part 120 is less than 20% based on the thickness of the support substrate 100, effect of heat dissipation may be weak. When the depth of the concave part 120 exceeds 80% based on the thickness of the support substrate 100, a physical strength of the support substrate 100 may become weak.
The back electrode layer 200 is provided on the top surface 100a of the support substrate 100. The back electrode layer 200 is a conductive layer. For example, a material used for the back electrode layer 200 may include metal such as molybdenum (Mo).
The back electrode layer 200 may include two or more layers. In this case, the layers may be formed by the same metal or different metals.
The light absorbing layer 300 is provided on the back electrode layer 200. The light absorbing layer 300 includes a group I-III-VI compound. For example, the light absorbing layer 300 may have the CIGSS (Cu(IN,Ga)(Se,S)2) crystal structure, the CISS (Cu(IN)(Se,S)2) crystal structure or the CGSS (Cu(Ga)(Se,S)2) crystal structure.
The energy bandgap of the light absorbing layer 300 may be in the range of about 1eV to about 1.8eV.
The buffer layer 400 is provided on the light absorbing layer 300. The buffer layer 400 directly makes contact with the light absorbing layer 300. The buffer layer 400 includes cadmium sulfide (CdS). The energy bandgap of the buffer layer 400 may be in the range of about 1.9eV to about 2.3eV.
The high resistance buffer layer 500 is provided on the buffer layer 400. The high resistance buffer layer 500 includes i-ZnO which is not doped with impurities. The energy bandgap of the high resistance buffer layer 500 may be in the range of about 3.1eV to about 3.3eV.
The front electrode layer 600 is provided on the light absorbing layer 300. In detail, the front electrode layer 600 is provided on the high resistance buffer layer 500.
The front electrode layer 600 is provided on the high resistance buffer layer 500. The front electrode layer 600 may be transparent. For example, a material used for the front electrode layer 600 may include an Al doped zinc oxide (AZO), an indium zinc oxide (IZO), or an indium tin oxide (ITO).
The front electrode layer 600 may have a thickness in the range of about 500㎚ to about 1.5㎛. When the front electrode layer 600 is formed by the Al doped zinc oxide (AZO), aluminum (Al) may be doped at the rate of about 2.5wt% to about 3.5wt%. The front electrode layer 600 is a conductive layer.
Hereinafter, a solar cell according to the second embodiment will be described with reference to FIG. 3. In the following description, the details of structures and components the same as those of the first embodiment or extremely similar to those of the first embodiment will be omitted for the purpose of clear and simple explanation.
FIG. 3 is a plan view showing a support substrate 100 included in the solar cell according to a second embodiment.
Referring to FIG. 3, a concave portion 120 may be provided in a back surface 100b of a support substrate 100 included in the solar cell according to the embodiment.
The concave part 120 may include a first concave portion 121 and a second concave portion 122. The second concave portion 122 may be spaced apart from the first concave portion 121.
For instance, the first concave portion 121 and the second concave portion 122 may extend along each side of the support substrate 100. In detail, as shown in FIG. 3, the concave part 120 may form a circle on the support substrate 100. That is, the first concave part 121 may form a circle in the central area CA of the support substrate 100 and the second concave part 122 may form a circle in the edge area EA of the support substrate 100. In this case, a width of the first concave part 121 may be larger than a width of the second concave part 122. Thus, heat may be efficiently dissipated from the central area CA of the support substrate 100.
Hereinafter, a solar cell according to a fourth embodiment will be described with reference to FIG. 4. FIG. 4 is a plan view showing a support substrate 100 included in the solar cell according to a third embodiment.
Referring to FIG. 4, the support substrate 100 included in the solar cell according to the third embodiment includes concave parts 120. The support substrate 100 includes a central area CA and an edge area EA surrounding the central area CA. The concave parts 120 may radially extend from the central area CA to the edge area EA. Therefore, the concave parts 120 are concentrated in the central area CA and gradually dispersed in the direction of the edge area EA. Accordingly, heat may be efficiently dissipated from the central area CA.
However, the embodiment is not limited to the above. The concave parts 120 may be formed with various patterns for heat dissipation of the support substrate 100.
Hereinafter, a solar cell according to a fourth embodiment will be described with reference to FIG. 5. FIG. 5 is a sectional view showing a solar cell according to a fourth embodiment.
Referring to FIG. 5, the solar cell 200 according to the fourth embodiment includes a support substrate 100 having a concave part 120, a heat dissipating part 140, a back electrode layer 200, a light absorbing layer 300, a buffer layer 400, a high resistance buffer layer 500, and a front electrode layer 600.
The support substrate 100 has a first surface 100a (hereinafter referred to as ‘top surface 100a’) and a second surface 100b (hereinafter referred to as ‘back surface 100b’) opposite each other. The light absorbing layer 300 and the buffer layer 400, and the front electrode layer 600 may be provided on the top surface 100a and the concave part 120 may be provided on the back surface 100b.
The heat dissipating part 140 may be provided in the concave part 120. The heat dissipating part 140 includes a first heat dissipating portion 141 and a second heat dissipating portion 142. In detail, the heat dissipating part 140 may include the first heat dissipating portion 141 filled in the concave part 120 and the second heat dissipating portion 142 exposed on the support substrate 100.
The heat dissipating part 140 may include metal. The heat dissipating part 140 may include at least one selected from the group consisting of metal including copper (Cu), aluminum (Al), silver (Ag), nickel (Ni), and chromium (Cr), and oxide having the metal. The heat dissipation part 140 may include metal or metal oxide having high electrical conductivity to rapidly discharge heat of the support substrate 100.
The heat dissipating part 140 may be provided by inserting paste including the metal and metal oxide into the concave part 120 or coating the paste on the back surface 100b of the support substrate 100. Particularly, the paste including the copper (Cu) or the aluminum (Al) may be easily inserted into the concave part due to the flexibility thereof.
A thickness t of the second heat dissipating part 142 may be in the range of 20% to 40% based on a depth of the concave part 120.
The heat dissipating part 140 may be provided in the back surface 100b of the support substrate 100 to rapidly dissipate heat of the support substrate 100, thereby reducing the concentration of the heat.
Any reference in this specification to “one embodiment,” “an embodiment,” “example embodiment,” etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the purview of one skilled in the art to effect such feature, structure, or characteristic in connection with other ones of the embodiments.
Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.

Claims (19)

  1. A solar cell comprising:
    a support substrate including a concave part; and
    a light absorbing layer, a buffer layer, and a front electrode layer on the support substrate.
  2. The solar cell of claim 1, wherein the support substrate comprises a first surface and a second surface opposite to each other, the light absorbing layer, the buffer layer, and the front electrode layer are provided on the first surface, and the concave part is provided on the second surface.
  3. The solar cell of claim 1, wherein at least one concave part is provided.
  4. The solar cell of claim 1, wherein the concave part comprises a first concave portion and a second concave portion, and the first concave portion and the second concave portion are provided in locations different from each other in the support substrate.
  5. The solar cell of claim 4, wherein the first concave portion extends in a first direction of the support substrate, and
    the second concave portion extends in a second direction crossing the first direction of the support substrate.
  6. The solar cell of claim 4, wherein the first concave portion and the second concave portion are spaced apart from each other.
  7. The solar cell of claim 4, wherein the first concave portion and the second concave portion extend along each side of the support substrate.
  8. The solar cell of claim 1, wherein the support substrate comprises a central area and an edge area surrounding the central area, and
    the concave part is provided in the central area and the edge area.
  9. The solar cell of claim 8, wherein the concave part radially extends from the central area to the edge area.
  10. The solar cell of claim 8, wherein the concave part comprises a first concave portion provided in the central area and a second concave portion provided in the edge area, and the first concave portion and the second portion have depths different from each other.
  11. The solar cell of claim 1, wherein a depth of the concave part is in a range of 20% to 80% based on the thickness of the support substrate.
  12. The solar cell of claim 10, wherein the first concave portion and the second concave portion have widths different from each other.
  13. The solar cell of claim 10, wherein the first concave portion has a width larger than a width of the second concave portion.
  14. The solar cell of claim 1, wherein the concave part has an area corresponding to 10% to 20% based on an area of the support substrate.
  15. A solar cell comprising:
    a support substrate including a concave part;
    a light absorbing layer, a buffer layer, and a front electrode layer on the support substrate; and
    a heat dissipating part in the concave part.
  16. The solar cell of claim 15, wherein the heat dissipating part comprises metal.
  17. The solar cell of claim 15, wherein the heat dissipating part comprises at least one selected from the group consisting of metal including copper (Cu), aluminum (Al), silver (Ag), nickel (Ni), and chromium (Cr), and oxide having the metal.
  18. The solar cell of claim 15, wherein the heat dissipating part comprises a first heat dissipating portion filled in the concave portion and a second heat dissipating portion exposed on the support substrate.
  19. The solar cell of claim 18, wherein the heat dissipating part has a thickness corresponding to 20% to 40% based on a depth of the concave part.
PCT/KR2012/007556 2011-09-20 2012-09-20 Solar cell WO2013042965A1 (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
KR10-2011-0094489 2011-09-20
KR1020110094488A KR20130030905A (en) 2011-09-20 2011-09-20 Solar cell
KR1020110094489A KR20130030906A (en) 2011-09-20 2011-09-20 Solar cell
KR10-2011-0094488 2011-09-20

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111599882A (en) * 2020-06-30 2020-08-28 扬州泽亮太阳能电池科技有限公司 High-strength thin-film battery
CN113257930A (en) * 2021-04-28 2021-08-13 杭州电子科技大学 Back reinforcing radiating silicon solar cell piece

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JP2000012773A (en) * 1998-04-23 2000-01-14 Sharp Corp Semiconductor device and its manufacture
KR20050011212A (en) * 2003-07-22 2005-01-29 전자부품연구원 Solar cell and method of manufacturing the same
JP2007201280A (en) * 2006-01-27 2007-08-09 Mitsubishi Heavy Ind Ltd Solar battery panel and solar cell power system
KR20110001306A (en) * 2009-06-30 2011-01-06 엘지이노텍 주식회사 Solar cell aparatus and method of fabricating the same

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JP2000012773A (en) * 1998-04-23 2000-01-14 Sharp Corp Semiconductor device and its manufacture
KR20050011212A (en) * 2003-07-22 2005-01-29 전자부품연구원 Solar cell and method of manufacturing the same
JP2007201280A (en) * 2006-01-27 2007-08-09 Mitsubishi Heavy Ind Ltd Solar battery panel and solar cell power system
KR20110001306A (en) * 2009-06-30 2011-01-06 엘지이노텍 주식회사 Solar cell aparatus and method of fabricating the same

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Publication number Priority date Publication date Assignee Title
CN111599882A (en) * 2020-06-30 2020-08-28 扬州泽亮太阳能电池科技有限公司 High-strength thin-film battery
CN113257930A (en) * 2021-04-28 2021-08-13 杭州电子科技大学 Back reinforcing radiating silicon solar cell piece

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