JP3189986U - Solar cell and solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solar cell having improved current collection efficiency and photoelectric conversion efficiency in a predetermined battery size. SOLUTION: A first bus bar electrode is provided with a substrate 31 having a light receiving surface and an electrode unit 33, and the electrode unit is stretched and arranged along a central straight line parallel to the light receiving surface and passing through a central point of the light receiving surface. The two finger electrode units include 34, two second bus bar electrodes 35 stretched parallel to both sides of the central straight line, and two finger electrode units 36 provided on both sides of the central straight line. Arranged point-symmetrically with respect to the center point of the light receiving surface, each of the finger electrode units has a plurality of finger electrodes stretched linearly in parallel with each other, and each of the finger electrodes is a first bus bar electrode and a first bus bar electrode. It has a first finger electrode portion 361 connected to one of two second bus bar electrodes, and each of the first finger electrode portions has an angle excluding a right line with respect to the first and second bus bar electrodes. It is arranged so as to tilt at. [Selection diagram] Fig. 2

Description

  The present invention relates to a solar cell and a solar cell module, and more particularly to a solar cell and a solar cell module using crystalline silicon.

  Conventionally, as shown in FIG. 8, a crystalline silicon solar cell includes a battery body 71 that photoelectrically converts sunlight energy into electric power, and a light-receiving-side light-receiving surface electrode unit 72 that is laminated on each of both surfaces of the battery body 71. A back electrode unit (not shown). The light-receiving surface electrode unit 72 includes a plurality of bus bar electrodes 721 that are elongated in the longitudinal direction and formed in a strip shape, and the bus bar electrodes 721 that extend in the horizontal direction perpendicular to the bus bar electrodes 721 and are parallel to each other so as to be parallel to each other. A plurality of finger electrodes 722 connected to each other are provided (see, for example, Patent Document 1).

Chinese Patent No. 1032996096

  In a conventional crystalline silicon solar cell, a constant current collection efficiency can be obtained by the light receiving surface electrode unit 72 having a predetermined pattern determined by the arrangement configuration of the bus bar electrode 721 and the finger electrode 722. The challenge is to further increase the current collection efficiency in size.

  An object of the present invention is to provide a solar cell and a solar cell module capable of improving current collection efficiency and photoelectric conversion efficiency with a new configuration and a predetermined battery size.

  To achieve the above object, according to one aspect, the present invention provides a substrate having a first surface as a light receiving surface, and a center of the first surface parallel to the first surface of the substrate. A first bus bar electrode arranged to extend along a central straight line passing through the point; and two second bus bar electrodes arranged to extend parallel to both sides of the central straight line; Two finger electrode units each provided on both sides of the central straight line, the two finger electrode units being arranged point-symmetrically with respect to the center point of the first surface, Each of the units has a plurality of finger electrodes formed to extend linearly in parallel with each other, and each of the finger electrodes is one of the first bus bar electrode and the two second bus bar electrodes. Each of the first finger electrode portions is inclined at an angle other than a right angle with respect to the first bus bar electrode and is connected to the one of the first finger electrode portions. And a light-receiving surface electrode unit disposed to be inclined at an angle other than a right angle with respect to the second bus bar electrode.

  According to another aspect, the present invention provides a first plate-like member, a second plate-like member, and the first plate-like member and the second plate, which are disposed so as to face each other. A plurality of solar cells according to the present invention arranged between the member, and a package that surrounds the solar cell and is disposed between the first plate member and the second plate member The solar cell module is provided with a member.

  Since the solar cell and the solar cell module according to the present invention are arranged so that the finger electrodes are inclined at an angle other than a right angle with respect to the bus bar electrode, the interval between the finger electrode portions can be shortened in a predetermined battery size. Thus, current collection efficiency and photoelectric conversion efficiency can be improved.

It is a partial cross section figure which shows the structure of 1st Embodiment of the solar cell module which concerns on this invention. It is a top view which shows the solar cell which concerns on 1st Embodiment. FIG. 3 is an enlarged plan view showing a part of the configuration of FIG. 2. It is sectional drawing of line AA in FIG. It is a top view which shows the solar cell of 2nd Embodiment of the solar cell module which concerns on this invention. It is a top view which shows the solar cell of 3rd Embodiment of the solar cell module which concerns on this invention. It is a top view which shows the solar cell of 4th Embodiment of the solar cell module which concerns on this invention. It is a top view which shows an example of the conventional solar cell.

  Hereinafter, the present invention will be described based on some preferred embodiments with reference to the drawings. The same or equivalent components, members, and processes shown in the drawings are denoted by the same reference numerals, and repeated descriptions are omitted as appropriate. Further, the embodiments do not limit the invention but are exemplifications, and all features and combinations described in the embodiments are not necessarily essential to the invention.

(First embodiment)
1 is a partial cross-sectional view showing a configuration of a first embodiment of a solar cell module according to the present invention, FIG. 2 is a plan view of the solar cell according to the first embodiment, and FIG. 4 is an enlarged plan view showing a part of the configuration, and FIG. 4 is a cross-sectional view taken along line AA in FIG. As shown in the figure, this solar cell module includes a first plate-like member 1 and a second plate-like member 2 which are arranged to face each other vertically, and a first plate-like member 1 and a second plate-like member. A plurality of solar cells 3 arranged in an array between 2 and the plurality of solar cells 3 are surrounded and arranged between the first plate-like member 1 and the second plate-like member 2. At least one package member 4 and a strip-shaped lead wire (ribbon) 5 for electrically connecting adjacent solar cells 3 and 3 to each other are provided.

  The first plate-like member 1 and the second plate-like member 2 can be glass or plastic plates, and are not particularly limited. In addition, as a plate-shaped member on the light-receiving surface side of the solar cell 3, a light-transmitting member is necessary. To make a solar cell that can receive both surfaces, the first plate-shaped member 1 and the first plate-shaped member As the two plate-like members 2, both of them should have light transmittance. For the package member 4, for example, a material such as an ethylene vinyl acetate (EVA) copolymer having optical transparency can be appropriately used, and there is no particular limitation.

  In this embodiment, the configuration of each of the plurality of solar cells 3 is the same. Hereinafter, one of the plurality of solar cells 3 will be described. The configuration of the battery used in one solar cell module is described below. May be the same or different.

  Solar cell 3 includes a substrate 31, a back electrode unit 32, and a light receiving surface electrode unit 33.

  As the substrate 31, for example, a rectangular or similar substrate is used. A square is a shape such as a square or a rectangle whose squares are all the same, and an amorphous silicon Si-based substrate is usually rectangular. The conformal shape, for example, has four long sides and four short sides connected between the long sides, and is a shape such as an octagon in which the short side is an arc shape or a straight line. The Si-based substrate is usually a square. The substrate 31 has a first surface 311 and a second surface 312 opposite to the first surface 311. In this embodiment, the first surface 311 is a light receiving surface, and the second surface 312 is a back surface back to back with the first surface 311. If the solar cell is a double-sided light receiving type, the second surface 312 is also a surface that can receive light.

  The first surface 311 has a central point 302 that is a geometrically central position of the first surface 311 and a central straight line 301 that extends along the first direction 61 so as to pass through the central point 302. . The first surface 311 extends along the first direction 61 and is positioned between the two first edges 313 located on both sides of the central straight line 301 and the first edge 313 spaced from each other. And two second edges 314. The central straight line 301 and the two first edges 313 are arranged at intervals in a second direction 62 that is a direction perpendicular to the first direction 61. The two second edges 314 extend along the second direction 62 and are arranged at intervals in the first direction.

The substrate 31 has an emitter layer 315 disposed on the back side of the first surface 311, and an antireflection layer 316 may be selectively formed on the emitter layer 315. One of the substrate 31 and the emitter layer 315 is an n-type semiconductor and the other is a p-type semiconductor, and has a structure in which an n-type semiconductor and a p-type semiconductor are joined. The antireflection layer 316 uses, for example, a silicon nitride (SiN _x ) compound in order to suppress light reflection and increase the amount of incident light.

  The back electrode unit 32 is provided on the second surface 312 of the substrate 31 and plays a role of outputting electric energy of the solar cell to the outside in a pair with the light receiving surface electrode unit 33. Since the arrangement of the back electrode unit 32 is a known technique in this technical field, details thereof are omitted here.

  The light-receiving surface electrode unit 33 is provided on the front side of the first surface 311 of the substrate 31 so as to penetrate the antireflection layer 316 and contact the emitter layer 315. In the first embodiment, the light-receiving surface electrode unit 33 includes a first bus bar electrode 34 disposed so as to extend parallel to the first surface 311 and along the central straight line 301, and both sides of the central straight line 301. A second bus bar electrode 35 arranged so as to extend parallel to the two, two finger electrode units 36 arranged on both sides of the central straight line 301, two linear first sub-electrodes 37, 2 And two linear second sub-electrodes 38. In this embodiment, two finger electrode units 36, two first sub-electrodes 37, and two second sub-electrodes 38 are provided so as to penetrate the antireflection layer 316 and contact the emitter layer 315. .

  The first bus bar electrode 34 and the two second bus bar electrodes 35 are extended in parallel to one side of the substrate 31, and parallel to the first edge 313 of the first surface 311 of the substrate 31. It is provided to be stretched. In the solar cell module package, the first bus bar electrode 34 and the two second bus bar electrodes 35 are connected to each other by a single strip-shaped conductor 5 by soldering.

  The light receiving surface electrode unit 33 is arranged point-symmetrically with respect to the center point 302 of the first surface 311. The pattern formed in a point-symmetric shape is a pattern in which a rotation pattern obtained by rotating the pattern 180 degrees around a certain point is not different from the pattern before the rotation. In this embodiment, even if the light-receiving surface electrode unit 33 is rotated 180 degrees around the center point, the pattern does not change, and the light-receiving surface electrode unit 33 is not line-symmetric. A pattern formed in a line-symmetric shape is a pattern in which a certain pattern is folded in half with respect to one symmetric line, and patterns on both sides of the symmetric line can be folded. If the light-receiving surface electrode unit 33 is formed in a point-symmetric shape, even if the solar cell 3 rotates 180 degrees, it does not change from the pattern before the rotation, so it can be installed regardless of the installation direction of the battery. Therefore, it is not necessary to consider the installation direction of the solar cell, so that the package can be simplified.

  Similar to the light receiving surface electrode unit 33, the two finger electrode units 36 are arranged not in line symmetry but in point symmetry. Each finger electrode unit 36 includes a plurality of finger electrodes 360, and the plurality of finger electrodes 360 are arranged in parallel along the first direction 61 at intervals, and each finger electrode 360 is The first finger electrode part 361 connected to one of the first bus bar electrode 34 and the two second bus bar electrodes 35 and the second finger electrode part 361 connected to one of the two second bus bar electrodes 35. And a finger electrode portion 362. The second finger electrode portion 362 is disposed between the one connected second bus bar electrode 35 and one of the two first edges 313. The first finger electrode portion 361 and the second finger electrode portion 362 are provided so as to penetrate the antireflection layer 316 and contact the emitter layer 315.

  In this embodiment, each first finger electrode portion 361 is inclined with respect to the first bus bar electrode 34 at an angle θ1 excluding a right angle, and is not perpendicular to the one connected second bus bar electrode 35. It arrange | positions so that it may incline at angle (theta) 2. θ1 and θ2 are angles other than a right angle, and may be the same or different. In this form, θ1 and θ2 are the same. Each of the first finger electrode portions 361 is formed in a V shape that is opened along the first direction 61 and is arranged so that the respective openings are directed in the same direction. In addition, the first finger electrode portion 361 on one side (left side of the central straight line 301 in FIG. 2) delimited by the first direction 61 of the first bus bar electrode 34 is opened at one end along the first direction 61. The first finger electrode portion 361 on the other side (the right side of the central straight line 301 in FIG. 2) is opened at the other end along the first direction 61 and formed in a V shape. The first finger electrode portion 361 on one side is formed in an inverted V shape. In addition, the 1st finger electrode part 361 of each finger electrode unit 36 may become V character shape opened in the same direction, respectively, and may become reverse V character shape.

  The first finger electrode portions 361 of the finger electrodes 360 in each finger electrode unit 36 are arranged in parallel with each other at the same interval d1 and the same pitch p1. The distance d1 between the adjacent first finger electrode portions 361 is the vertical distance between the adjacent first finger electrode portions 361, and the pitch p1 is the vertical distance between the same portions of the adjacent first finger electrode portions 361. It is. The line width w1 of the first finger electrode portion 361 of each finger electrode 360 is smaller than the line width a of the first bus bar electrode 34 and smaller than the line width b of the connected second bus bar electrode 35.

  In this embodiment, each first finger electrode portion 361 has a first extending portion 363 close to the central straight line 301 and a central straight line inclined with respect to the first extending portion 363 so as to be formed in a V shape. And a second elongated portion 364 remote from 301. Note that the first finger electrode portions 361 of the plurality of finger electrodes 360 in each finger electrode unit 36 are parallel to each other, the corresponding extending portions of the plurality of finger electrodes 360 are parallel, that is, the plurality of first fingers. Each of the first extended portions 363 of the electrode part 361 is parallel to each other, and each of the second extended portions 364 is parallel to each other.

  Each of the second finger electrode portions 362 of the plurality of finger electrodes 360 in each finger electrode unit 36 is formed in a V shape opened along the first direction 61, and each opening faces in the same direction. Are lined up like The plurality of second finger electrode portions 362 of each finger electrode unit 36 is formed in a V shape opened in the same direction as the plurality of first finger electrode portions 361. Note that the second finger electrode portions 362 in the adjacent finger electrode units 36 may be V-shaped or inverted V-shaped and opened in the same direction. The second finger electrode portion 362 on one side (left side of the central straight line 301 in FIG. 2) delimited by the first direction 61 of the one bus bar electrode 34 is open at one end along the first direction 61. The second finger electrode portion 362 on the other side (the right side of the central straight line 301 in FIG. 2) is opened at the other end along the first direction 61, and is formed on the one side formed in a V shape. The second finger electrode portion 362 is formed in an inverted V shape.

  Each of the second finger electrode portions 362 of the finger electrode 360 in each finger electrode unit 36 is arranged in parallel with the same interval d2 and the same pitch p2. The interval d2 between the adjacent second finger electrode portions 362 is the vertical distance between the adjacent second finger electrode portions 362, and the pitch p2 is the vertical distance between the same portions of the adjacent second finger electrode portions 362. is there. In this embodiment, each second finger electrode portion 362 is formed with a V-shaped third extension portion 365 close to the center straight line 301, and the center straight line 301 is inclined with respect to the third extension portion 365. And a fourth stretched portion 366 remote from the. Note that the second finger electrode portions 362 of the plurality of finger electrodes 360 in each finger electrode unit 36 are parallel to each other. The corresponding extended portions of the plurality of finger electrodes 360 are parallel, that is, the plurality of second fingers. Each of the third extended portions 365 of the electrode part 362 is parallel to each other, and each of the fourth extended portions 366 is parallel to each other.

  Each of the two first sub-electrodes 37 is disposed between the corresponding finger electrode unit 36 and the corresponding first edge 313 on both sides of the central straight line 301, and parallel to the corresponding first edge 313. It is provided so as to extend along the first direction 61. In this embodiment, the two first sub-electrodes 37 are connected to the corresponding finger electrode units 36 so as to connect at least the second finger electrode portions 362 of the plurality of finger electrodes 360 of the corresponding plurality of finger electrodes 360. ing. By connecting the plurality of finger electrodes 360 by the first sub-electrode 37, a more preferable conductive network can be formed, and the current collection efficiency can be improved. The second finger electrode portion 362 is installed to be inclined at an angle θ3 excluding a right angle with respect to the corresponding first sub electrode 37 connected thereto.

  In the present embodiment, each first sub-electrode 37 is connected to each of the finger electrodes 360 in the corresponding finger electrode unit 36 to which the first sub-electrode 37 is connected, but is not limited thereto. The plurality of finger electrodes 360 in each finger electrode unit 36 includes the second finger electrode portion 362, but is not limited thereto. For example, the plurality of finger electrodes 360 connected to the first sub-electrode 37 is the second finger electrode 360. The finger electrode portion 362 may be included. The second finger electrode part 362 of the plurality of finger electrodes 360 connected to the first sub electrode 37 is disposed between the connected second bus bar electrode 35 and the connected first sub electrode 37. It is provided as follows.

  The two second sub-electrodes 38 are spaced along the first direction 61 so as to connect corresponding one ends and the other ends of the first bus bar electrode 34 and the second bus bar electrode 35, respectively. They are arranged so as to extend along the second direction 62 in parallel with the corresponding second edge 314. Since the two first sub-electrodes 37 and the two second sub-electrodes 38 are formed in a quadrilateral shape, a more preferable conductive network can be formed, and current collection efficiency can be improved. .

  Since the first finger electrode portion 361 of the plurality of finger electrodes 360 is provided to be inclined with respect to the first bus bar electrode 34 and the second bus bar electrode 35 so as to be inclined at an angle other than a right angle, The shortest distance between adjacent finger electrode parts 361 can be effectively shortened with respect to the conventional solar cell. A distance D between adjacent finger electrodes 722 in a conventional solar cell (see FIG. 8), that is, a distance between connection points at which the adjacent first finger electrode portions 361 are connected to the first bus bar electrode 34. When D is set, the vertical distance d1 between the adjacent first finger electrode portions 361 satisfies the relationship d1 = D × sin θ1. From this, it can be seen that d1 <D. Accordingly, the first finger electrode portion 361 is provided so as to be inclined with respect to the first bus bar electrode 34 and the second bus bar electrode 35 so as to be inclined at an angle other than a right angle, so that a predetermined battery has a predetermined battery. The distance between finger electrodes 360 adjacent to each other in size can be shortened. By shortening the interval between adjacent finger electrodes 360, the carrier transmission distance between adjacent finger electrodes 360 can be shortened. Thus, carrier transmission efficiency can be increased at a predetermined battery size, and current can be efficiently absorbed on the surface of the battery, so that current collection efficiency and photoelectric conversion efficiency can be improved. Further, since the two finger electrode units 36 are arranged point-symmetrically with respect to the center point 302, packaging can be simplified.

(Second Embodiment)
FIG. 5 is a plan view showing a solar cell of a second embodiment of the solar cell module according to the present invention.

  In the second embodiment, the difference from the first embodiment is that the plurality of first finger electrode portions 361 and the plurality of second finger electrode portions 362 in the two finger electrode units 36 are opposite to each other. It is in the point formed in the V-shape opened in the direction of. The light-receiving surface electrode unit 33 is formed in a point-symmetric shape with respect to the center point 302 as in the first embodiment.

  Since the solar cell module configured with the solar cell according to the second embodiment can efficiently absorb current on the surface of the battery, similarly to the first embodiment, the size of a predetermined battery The current collection efficiency and the photoelectric conversion efficiency can be improved, and the package can be simplified.

(Third embodiment)
FIG. 6 is a plan view showing a solar cell of a third embodiment of the solar cell module according to the present invention.

  In the third embodiment, the plurality of first finger electrode portions 361 and the second finger electrode portions 362 on the left side of the central straight line 301 are formed in an inverted V shape opened in the same direction. The plurality of first finger electrode portions 361 and the second finger electrode portions 362 on the right side are formed in a V shape opened in the same direction. The light-receiving surface electrode unit 33 is formed in a point-symmetric shape with respect to the center point 302 as in the first embodiment and the second embodiment.

  The solar cell module configured as in the third embodiment can obtain the same effects as those of the first and second embodiments.

(Fourth embodiment)
FIG. 7 is a plan view showing a solar cell of a fourth embodiment of the solar cell module according to the present invention.

  The first bus bar electrode 34 and the two second bus bar electrodes 35 are arranged so as to extend along the first direction 61 at a predetermined interval from each other. The second finger electrode 362 is perpendicular to the first bus bar electrode 34 and the second bus bar electrode 35, not parallel to the first direction 61 and not parallel to the second direction 62. It is linearly stretched and arranged so as to be inclined at an angle other than that. The plurality of first finger electrode portions 361 in each finger electrode unit 36 are provided in parallel with each other at the same interval and the same pitch. The plurality of second finger electrode portions 362 in each finger electrode unit 36 are provided in parallel with each other at the same interval and the same pitch. The light receiving surface electrode unit 33 is formed in a point-symmetric shape with respect to the center point 302 as in the above embodiment.

  The solar cell module configured as in the fourth embodiment can obtain the same effects as those in the first to third embodiments.

  Since the solar cell and the solar cell module according to the present invention configured as described above are arranged so that the finger electrode is inclined at an angle other than a right angle with respect to the bus bar electrode, the finger electrode portion in a predetermined battery size The interval between them can be shortened, and current collection efficiency and photoelectric conversion efficiency can be improved.

  The solar cell according to the present invention is useful as a solar cell for improving its electrical characteristics.

DESCRIPTION OF SYMBOLS 1 1st plate-shaped member 2 2nd plate-shaped member 3 Solar cell 4 Package member 5 Conductive wire 31 Board | substrate 32 Back surface electrode unit 33 Light-receiving surface electrode unit 34 1st bus-bar electrode 35 2nd bus-bar electrode 36 Finger electrode unit 37 First sub-electrode 38 Second sub-electrode 61 First direction 62 Second direction 301 Central straight line 302 Center point 311 First surface 312 Second surface 313 First edge 314 Second edge 315 Emitter layer 316 Antireflection layer 360 Finger electrode 361 First finger electrode portion 362 Second finger electrode portion 363 First extended portion 364 Second extended portion 365 Third extended portion 366 Fourth extended portion

Claims (14)

A substrate having a first surface as a light receiving surface;
A first bus bar electrode arranged to extend along a central straight line that is parallel to the first surface of the substrate and passes through a center point of the first surface; Two second bus bar electrodes arranged so as to extend in parallel, and two finger electrode units respectively provided on both sides of the central straight line, the two finger electrode units being Each of the finger electrode units has a plurality of finger electrodes formed so as to extend linearly in parallel with each other, and each of the finger electrodes Has a first finger electrode portion connected to one of the first bus bar electrode and the two second bus bar electrodes, and each of the first finger electrode portions With inclined at an angle other than a right angle with respect to the bus bar electrode, and the light-receiving surface electrode units disposed so as to be inclined at an angle other than a right angle with respect to the one of the second bus bar electrode coupled,
A solar cell comprising: The first surface has a first edge;
The light receiving surface electrode unit is provided so as to be connected to at least the plurality of finger electrodes in the plurality of finger electrodes so as to extend in parallel with the corresponding first edge. Have
The plurality of finger electrodes connected to the first sub-electrode includes a second bus bar electrode connected to the first sub-electrode and a second finger electrode portion connected between the first sub-electrode. The solar cell according to claim 1.   The solar cell according to claim 2, wherein the first sub electrode and the second finger electrode portion connected to the first sub electrode are connected at an angle other than a right angle.   2. The solar cell according to claim 1, wherein the first finger electrode portions of the plurality of finger electrodes in the finger electrode unit are arranged in parallel with each other at the same interval.   2. The solar cell according to claim 1, wherein the first finger electrode portions of the plurality of finger electrodes in the finger electrode unit are arranged in parallel with each other at the same pitch.   2. The solar cell according to claim 1, wherein the first finger electrode portions of the plurality of finger electrodes in the finger electrode unit are formed in a V shape opened in the same direction. . The first surface has two first edges located on opposite sides of the central straight line;
Each of the finger electrodes has a second finger electrode portion connected to one of the two second bus bar electrodes,
2. The sun according to claim 1, wherein the second finger electrode part is disposed between the one connected second bus bar electrode and one of the two first edges. battery.   The solar cell according to claim 7, wherein the second finger electrode portions of the plurality of finger electrodes in the finger electrode unit are arranged so as to be arranged in parallel at the same interval.   The solar cell according to claim 7, wherein the second finger electrode portions of the plurality of finger electrodes in the finger electrode unit are arranged in parallel with each other at the same pitch.   8. The solar cell according to claim 7, wherein the second finger electrode portions of the plurality of finger electrodes in the finger electrode unit are formed in a V shape opened in the same direction. . The substrate has a square shape or a similar shape,
2. The solar cell according to claim 1, wherein the first bus bar electrode and the two second bus bar electrodes are arranged to extend parallel to one side of the substrate.   The line width of the first finger electrode portion of each of the finger electrodes is smaller than the line width of the first bus bar electrode and smaller than the line width of the connected second bus bar electrode. The solar cell according to claim 1.   2. The solar cell according to claim 1, wherein the light-receiving surface electrode unit is arranged point-symmetrically with respect to the center point of the first surface. A first plate-like member and a second plate-like member which are arranged to face each other vertically;
The plurality of solar cells according to any one of claims 1 to 13, which are arranged between the first plate-like member and the second plate-like member,
A solar cell module comprising a package member surrounding the solar cell and disposed between the first plate-like member and the second plate-like member.

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