Classifications

• • 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
  • H01L31/06—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 characterised by at least one potential-jump barrier or surface barrier
  • H01L31/072—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 characterised by at least one potential-jump barrier or surface barrier the potential barriers being only of the PN heterojunction type
  • H01L31/0749—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 characterised by at least one potential-jump barrier or surface barrier the potential barriers being only of the PN heterojunction type including a AIBIIICVI compound, e.g. CdS/CulnSe2 [CIS] heterojunction solar 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
  • H01L31/04—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
  • H01L31/02—Details
  • H01L31/0224—Electrodes
  • H01L31/022408—Electrodes for devices characterised by at least one potential jump barrier or surface barrier
  • H01L31/022425—Electrodes for devices characterised by at least one potential jump barrier or surface barrier for solar 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
  • H01L31/02—Details
  • H01L31/0236—Special surface textures
  • H01L31/02366—Special surface textures of the substrate or of a layer on the substrate, e.g. textured ITO/glass substrate or superstrate, textured polymer layer on glass 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
  • H01L31/04—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
  • H01L31/042—PV modules or arrays of single PV cells
  • H01L31/0445—PV modules or arrays of single PV cells including thin film solar cells, e.g. single thin film a-Si, CIS or CdTe solar cells
  • H01L31/046—PV modules composed of a plurality of thin film solar cells deposited on the same substrate
  • H01L31/0463—PV modules composed of a plurality of thin film solar cells deposited on the same substrate characterised by special patterning methods to connect the PV cells in a module, e.g. laser cutting of the conductive or active layers
• • 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
• • 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 embodiment relates to a solar cell and a method for manufacturing the same.
• a CIGS-based solar cell has been extensively used, in which the CIGS-based solar cell is a PN hetero junction device having a support substrate structure including a glass support substrate, a metallic back electrode layer, a P type CIGS-based light absorbing layer, a buffer layer, and an N type transparent electrode layer.
• the embodiment provides a solar cell having improved reliability and a method for manufacturing the same.
• a solar cell includes a substrate, a back electrode layer on the substrate, a light absorbing layer on the back electrode layer, a buffer layer on the light absorbing layer, and a window layer on the buffer layer.
• the lateral surfaces of the first through holes are inclined with respect to the top surface of the substrate.
• a method for manufacturing a solar cell includes forming a back electrode layer on a substrate, etching a portion of the back electrode layer to expose a top surface of the substrate; and forming a light absorbing layer, a buffer layer, and a window layer on the back electrode layer.
• a laser beam is irradiated onto the substrate while being inclined with respect to the top surface of the substrate when the portion of the back electrode layer is etched.
• the lateral surfaces of the back electrode layer divided into a plurality of back electrode layers by the first through holes can be inclined with respect to the substrate. Accordingly, the burr cannot be prevented from occurring due to the thermal shock caused by the laser beams when the first through holes are formed.
• FIG. 1 is a plan view showing a solar power generator according to the embodiment
• FIG. 2 is a sectional view taken along line A-A'of FIG. 1;
• FIG. 3 is an enlarged sectional view of B of FIG. 2;
• FIGS. 4 to 7 are sectional views showing a method for manufacturing a solar cell according to the embodiment.
• a layer (or film), a region, a pattern, or a structure is referred to as being 'on' or 'under' another substrate, another layer (or film), another region, another pad, or another pattern, it can be directly or indirectly on the other substrate, layer (or film), region, pad, or pattern, or one or more intervening layers may also be present.
• a position of the layer has been described with reference to the drawings.
• each layer shown in the drawings may be exaggerated, omitted or schematically drawn for the purpose of convenience or clarity.
• the size of elements does not utterly reflect an actual size.
• FIG. 1 is a plan view showing a solar power generator according to the embodiment
• FIG. 2 is a sectional view taken along line A-A'of FIG. 1
• the solar cell according to the embodiment includes a support substrate 100, an back electrode layer 200 on the support substrate 100, a light absorbing layer 300 on the back electrode layer 200, a buffer layer 400 and a high resistance buffer layer 500 on the light absorbing layer 300, and a window layer 600 on the high resistance buffer layer 500
• 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 window layer 600.
• the support substrate 100 may include an insulator.
• the support substrate 100 may include a glass substrate, a plastic substrate, or a metallic substrate.
• the support substrate 100 may include a soda lime glass substrate.
• the support substrate 100 includes soda lime glass
• sodium (Na) contained in the soda lime glass may be diffused into the light absorbing layer 300 including CIGS when manufacturing the solar cell. Accordingly, the concentration of charges of the light absorbing layer 300 may be increased. Therefore, the photoelectric conversion efficiency can be increased.
• the support substrate 100 may include a ceramic substrate including alumina, stainless steel, or polymer having flexibility. Therefore, the support substrate 100 may be transparent, rigid, or flexible.
• the back electrode layer 200 is provided on the support substrate 100.
• the back electrode layer 200 is a conductive layer.
• the back electrode layer 200 moves charges generated from the light absorbing layer 300 of the solar cell so that current can flow to the outside of the solar cell.
• the back electrode layer 200 must represent high electrical conductivity or low resistivity to perform the functions.
• the back electrode layer 200 makes contact with a CIGS compound constituting the light absorbing layer 300, the back electrode layer 200 must make ohmic contact with the light absorbing layer 300 so that a low contact resistance value can be obtained.
• the back electrode layer 200 must maintain stability in the high-temperature condition when the heat treatment process is performed under sulfur (S) or selenium (Se) atmosphere as a CIGS compound is formed.
• the back electrode layer 200 must represent a superior adhesive property with respect to the support substrate 100 such that the back electrode layer 200 is not delaminated from the support substrate 100 due to the difference in the thermal expansion coefficient between the back electrode layer 200 and the support substrate 100.
• the back electrode layer 200 may include one selected from the group consisting of molybdenum (Mo), gold (Au), aluminum (Al), chrome (Cr), tungsten (W), and copper (Cu).
• Mo represents the low thermal expansion coefficient difference with the support substrate 100 as compared with other elements. Accordingly, the Mo represents a superior adhesive property with respect to the support substrate 100, so that delamination from the support substrate 100 can be prevented.
• the Mo satisfies the characteristics required for the back electrode layer 200.
• the back electrode layer 200 may include at least two layers.
• the layers include the same metal, or different metals.
• First through holes TH1 are formed in the back electrode layer 200.
• the first through holes TH1 are open regions to expose portions of the top surface of the support substrate 100.
• the first through holes TH1 may extend in one direction when viewed in a plan view.
• the width of the support substrate 100 exposed through the first through hole TH1 is in the range of about 20 ⁇ m to about 150 ⁇ m.
• the back electrode layer 200 is divided into a plurality of back electrodes by the first through holes TH1.
• the back electrodes are defined by the first through holes TH1.
• the back electrodes are arranged in the shape of a stripe .
• the back electrodes may be arranged in the form of a matrix.
• the first through holes TH1 may be formed in the form of a lattice when viewed in a plan view.
• the first through holes TH1 are patterned by using a laser.
• a conventional laser-based patterning process is performed by irradiating a laser beam perpendicularly to the support substrate 100 in order to form the first through holes TH1, burr may occur in the back electrode layer 200 due to thermal expansion and thermal shock in the region into which the laser beam is irradiated.
• the burr refers to a process trace which occurs at the edge of the first through hole TH1 because a tip of the edge is thinly rolled when the back electrode layer 200 is patterned.
• the back electrode layer 200 grown from the support substrate 100 may include a plurality of layers having different densities.
• a lower back electrode layer 200 in the contact with the support substrate 200 may have a low density in order to improve the adhesive property with respect to the support substrate 100.
• An upper back electrode layer in the contact with the light absorbing layer 300 may have a higher density based on electrical conductivity.
• the thermal expansion coefficient of the lower back electrode layer having the lower density may have a greater value due to thermal shock caused by the laser beam when performing the patterning process to form the first through holes TH1.
• the edges of the back electrode layer in which the first through holes TH1 are formed are curved upward.
• the light absorbing layer 300 may be not uniformly grown, but have the shape in which grains are combined with each other. Accordingly, coverage failures may occur.
• the grains may be spaced away from the substrate 100 by a predetermined distance, the reliability of the device may be improved.
• FIG. 3 is an enlarged view of B of FIG. 2.
• lateral surfaces 210 and 220 of the first through holes TH1 are inclined at a predetermined angle ⁇ with respect to a normal line to the support substrate 100.
• the angle ⁇ may be formed in the range of 10° ⁇ 80° preferably, in the range of 30° ⁇ 80°
• the lateral surfaces 210 and 220 of the first through holes TH1 may be formed at the same angle, or may be formed at different angles within the angular range.
• the back electrode layer 200 may be formed in the shape of a trapezoid representing that the back electrode layers 200 have etch areas different from each other in the upper and lower portions thereof by the angle ⁇ .
• laser beams are incident in a plurality of directions in order to form the first through holes TH1 while being inclined with respect to the normal surface to the support substrate 100, so that the etch areas of the first through holes TH1 are enlarged upward.
• the lateral surface of the back electrode layer 200 is inclined with respect to the support substrate 100.
• the etch area is increased upward from the support substrate 100, the width of the first through holes TH1 may be increased upward. Accordingly, the probability of generating the burr due to the difference in thermal expansion coefficient between the upper and lower portions of the back electrode layer 200 is reduced, so that the reliability of the device can be improved.
• the light absorbing layer 300 may be formed on the back electrode layer 200.
• the light absorbing layer 300 includes a P type semiconductor compound.
• the light absorbing layer 300 includes group I-III-V compounds.
• the light absorbing layer 300 may have a Cu-In-Ga-Se-based crystal structure (Cu(In,Ga)Se 2 ;CIGS), a Cu-In-Se-based crystal structure, a Cu-Ga-Se based crystal structure, or a Cu-Zn-Sn- Se-based crystal structure.
• the buffer layer 400 and the high resistance buffer layer 500 may be formed on the light absorbing layer 300.
• PN junction is formed between a CIGS compound thin film including a P type semiconductor and the window layer 600 including an N type semiconductor.
• the buffer layer 400 includes group II-VI materials such as CdS or ZnS, and the CdS represents more improved generating efficiency of the solar cell.
• the high-resistance buffer layer 500 includes i-ZnO that is not doped with impurities.
• the energy band gap of the high-resistance buffer layer 500 is in the range of about 3.1eV to about 3.3eV.
• the window layer 600 is formed on the high-resistance buffer layer 500.
• the window layer 600 is a transparent conductive layer.
• the resistance of the window layer 600 is higher than the resistance of the back electrode layer 200.
• the window layer 600 includes an oxide.
• the window layer 600 may include zinc oxide, indium tin oxide (ITO), or indium zinc oxide (IZO).
• the oxide may include conductive impurities such as aluminum (Al), alumina (Al 2 O 3 ), magnesium (Mg), or gallium (Ga).
• the window layer 600 may include Al doped zinc oxide (AZO) or Ga doped zinc oxide (GZO).
• the burr can be prevented from occurring due to the thermal shock caused by the laser beams when the first through holes TH1 are formed.
• the reliability of the solar cell can be improved.
• FIGS. 4 to 7 are sectional views showing a method for manufacturing the solar power generator according to the embodiment. The details of the method for manufacturing the solar cell apparatus will be given based on the description about the solar cell apparatus that has been described.
• the back electrode layer 200 is patterned, thereby forming the first through holes TH1. Accordingly, a plurality of back electrodes are formed on the support substrate 100.
• the back electrode layer 200 is patterned by using a laser.
• the first through holes TH1 expose the top surface of the support substrate 100, and may have a width in the range of about 80 ⁇ m to about 200 ⁇ m.
• an additional layer such as an anti-diffusion layer may be interposed between the support substrate 100 and the back electrode layer 200.
• the first through holes TH1 expose the top surface of the additional layer.
• the first through holes TH1 may have an inclined lateral surface. To this end, a plurality of laser beams may be irradiated to the support substrate 100 at an inclined angle with respect to the normal line to the support substrate 100.
• the back electrode layer 200 may be formed in the shape of a trapezoid representing that the back electrode layer 200 has etch areas different from each other in the upper and lower portions thereof.
• a laser beam is incident in a plurality of directions in order to form the first through hole TH1 while being inclined with respect to the normal surface to the support substrate 100. Accordingly, the first through hole TH1 has an etch area enlarged upward.
• the first through holes TH1 are formed by overlapping focuses of the laser beams with each other by about 5% to about 60%.
• the first through holes TH1 may be formed by a laser beam having a wavelength in the range of about 500nm to about 1200nm.
• the light absorbing layer 300, the buffer layer 400, and the high-resistance buffer layer 500 are formed on the back electrode layer 200.
• the light absorbing layer 300 may be formed through a sputtering process or an evaporation scheme.
• the light absorbing layer 300 may be formed through various schemes such as a scheme of forming a Cu(In,Ga)Se2 (CIGS) based-light absorbing layer 300 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.
• CGS Cu(In,Ga)Se2
• the metallic precursor layer is formed on the back contact electrode 200 through a sputtering process employing a Cu target, an In target, or a Ga target.
• the metallic precursor layer is subject to the selenization process so that the Cu(In,Ga)Se2 (CIGS) based-light absorbing layer 300 is formed.
• the sputtering process and the selenization process employing the Cu target, the In target, and the Ga target may be simultaneously performed.
• a CIS or a CIG light absorbing layer 300 may be formed through a sputtering process and the selenization process employing only Cu and In targets or only Cu and Ga targets.
• the buffer layer 400 may be formed after depositing cadmium sulfide through a sputtering process or a CBD (chemical bath deposition) scheme.
• the second through holes TH2 may be formed through a mechanical device such as a tip or a laser.
• the light absorbing layer 300 and the buffer layer 400 may be patterned by the tip having a width of about 40 ⁇ m to about 180 ⁇ m.
• the second through holes TH2 may be formed by the laser having the wavelength of about 200nm to about 600nm nanometers.
• the second through holes TH2 may have a width in the range of about 30 ⁇ m to about 100 ⁇ m.
• the second through holes TH2 is formed to expose a portion of the top surface of the back electrode layer 200.
• the window layer 600 is formed above the light absorbing layer 300 and at inner parts of the second through holes TH2.
• the window layer 600 is formed by depositing a transparent conductive material above the buffer layer 400 and at the inner parts of the second through holes TH2.
• the transparent conductive material is filled in the second through holes TH2, and the window layer 600 directly makes contact with the back electrode layer 200.
• the window layer 600 may be formed by depositing a transparent conductive material at an oxygen-free atmosphere.
• the window layer 600 may be formed by depositing AZO under the atmosphere of inert gas that does not include oxygen.
• third through holes TH3 portions of the buffer layer 400, the high-resistance buffer layer 500, and the window layer 600 are removed to form third through holes TH3. Accordingly, the window layer 600 is patterned, thereby defining a plurality of windows and a plurality of cells C1, C2, ... and CN.
• the width of each third through hole TH3 may be in the range of about 30 ⁇ m to about 200 ⁇ m.
• Connection parts 700 are provided in the second through holes TH2.
• the connection parts 700 extend downward from the window layer 600 to make contact with the back electrode layer 200.
• the connection part 700 extends from the window of the first cell to make contact with the back electrode of the second cell.
• connection parts 700 connect adjacent cells to each other.
• the connection parts 700 connect windows and back electrodes, which are contained in the cells C1, C2, ... and CN adjacent to each other, to each other.
• connection part 700 is integrated with the window layer 600.
• the connection part 700 includes the same material as that constituting the window layer 600.
• the portions of the buffer layer 400, the high-resistance buffer layer 500, and the window layer 600 are removed to form the third through hole TH3. Accordingly, the window layer 600 is patterned, thereby defining a plurality of windows and a plurality of cells C1, C2, ... and C N .
• burrs can be prevented from occurring due to the thermal shock caused by a laser beam when the first through holes are formed. Accordingly, the reliability of the solar cell can be improved.
• 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.

Applications Claiming Priority (2)

Publications (2)

Family

ID=46581006

Family Applications (1)

Country Status (5)

Families Citing this family (4)

Citations (4)

Family Cites Families (4)

• 2011
  • 2011-01-25 KR KR1020110007515A patent/KR101189432B1/ko not_active IP Right Cessation
  • 2011-10-06 WO PCT/KR2011/007406 patent/WO2012102455A1/en active Application Filing
  • 2011-10-06 EP EP11857332.8A patent/EP2529411A4/de not_active Withdrawn
  • 2011-10-06 CN CN2011800260179A patent/CN102918655A/zh active Pending
  • 2011-10-06 JP JP2013550375A patent/JP2014503130A/ja active Pending

Patent Citations (4)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events