Unit cell, solar cell having the unit cell, and method for manufacturing the solar cell

Abstract

The present invention relates to a solar cell, a unit cell included in the solar cell, and a method for manufacturing the solar cell. The solar cell includes: a first unit cell made of one of a plurality of pieces formed by dividing a base substrate; and a second unit cell coupled to the first unit cell, wherein the first unit cell includes a first cell electrode formed on the first unit substrate to have conductivity, the second unit cell includes a second cell electrode formed on the second unit substrate to have conductivity, the second cell electrode and the first cell electrode are bonded to each other without a bonding material, thereby coupling the second unit cell to the first unit cell.

Description

Technical Field

[0001] The invention relates to a solar cell and a solar cell formed by combining a wafer-type solar cell and a thin-film-type solar cell. Background Art

[0002] Solar cells are devices that convert light energy into electrical energy based on the properties of semiconductors.

[0003] Solar cells have a PN junction structure that combines a P-type semiconductor and an N-type semiconductor. When sunlight shines on a solar cell with a PN junction structure, the energy of the incident sunlight generates holes and electrons in the semiconductor. At this time, due to the electric field generated in the PN junction, holes (+) move to the P-type semiconductor and electrons (-) move to the N-type semiconductor, thereby generating an electric potential to generate electricity.

[0004] Solar cells can be divided into thin-film solar cells and wafer-type solar cells.

[0005] A wafer-type solar cell is a solar cell manufactured using a semiconductor material such as a silicon wafer as a substrate, and a thin-film-type solar cell is a solar cell manufactured by forming a thin-film semiconductor on a substrate such as glass.

[0006] The efficiency of wafer-type solar cells is better than that of thin-film solar cells, but thin-film solar cells have the advantage of lower manufacturing costs compared to wafer-type solar cells.

[0007] Therefore, a solar cell combining a wafer type solar cell and a thin film type solar cell is proposed. Hereinafter, a solar cell of the prior art will be introduced.

[0008] The conventional method for manufacturing a solar cell may include the following processes.

[0009] First, a substrate having a plurality of partitions formed therein is prepared. The partitions are used to divide the substrate into a plurality of pieces.

[0010] Next, a surface electrode is formed on one surface of the substrate, and the surface electrode is cured.

[0011] Next, another surface electrode is formed on the other surface of the substrate, and the other surface electrode is cured. Thus, a base substrate having the surface electrode and the other surface electrode formed thereon is obtained.

[0012] Next, a bonding material is distributed on the other surface electrode. The bonding material may be a material having bonding strength, which can bond the separated pieces to each other.

[0013] Next, the substrate is divided into a plurality of pieces using a separator. Thus, the base substrate can be divided into a plurality of unit cells.

[0014] Next, a plurality of unit cells are bonded using a bonding material, and the bonded unit cells are cured, thereby completing a solar cell.

[0015] It is known that in conventional solar cells, unit cells are connected to each other by a bonding material. However, since the generated energy passes through the bonding material during the flow of the unit cells, the conventional solar cell has a problem of reduced power generation efficiency due to the resistance of the bonding material. Summary of the invention

[0016] Technical issues

[0017] To solve the aforementioned problems, the present invention relates to a unit cell, a solar cell having the unit cell, and a method for manufacturing the solar cell, which can reduce the degree to which the power generation efficiency of the solar cell is reduced due to the resistance of a bonding material.

[0018] Technical Solution

[0019] The present invention may include the following elements to solve the aforementioned technical problems.

[0020] According to the present invention, a method for manufacturing a solar cell may include: a substrate preparation process for preparing a substrate in which a plurality of partitions are formed for dividing the substrate into a plurality of pieces; a first electrode formation process for forming a plurality of first substrate electrodes having conductivity on one surface of the substrate; a first curing process for curing the first substrate electrodes; a second electrode formation process for forming a plurality of second substrate electrodes having conductivity and in an uncured state on the other surface of the substrate; a dividing process for dividing the substrate into a plurality of pieces through the partitions to form a plurality of unit cells; and a bonding process for bonding the unit cells through the second substrate electrodes in an uncured state.

[0021] According to the present invention, a solar cell may include: a first unit cell made of one of a plurality of pieces formed by dividing a base substrate; and a second unit cell coupled to the first unit cell. The first unit cell may include a first cell electrode formed on the first unit substrate and having conductivity. The second unit cell may include a second cell electrode formed on the second unit substrate and having conductivity. The second cell electrode and the first cell electrode may be bonded to each other without a bonding material to couple the second unit cell to the first unit cell.

[0022] According to the present invention, a solar cell may include: a first unit cell made of one of a plurality of pieces formed by dividing a base substrate; and a second unit cell coupled to the first unit cell. The first unit cell may include a first cell electrode formed on the first unit substrate to have conductivity. The second unit cell may include a second cell electrode formed on the second unit substrate to have conductivity. The second cell electrode is joined to the first cell electrode to couple the second unit cell to the first unit cell.

[0023] According to the present invention, a unit battery may include: a unit substrate made of one of a plurality of pieces formed by dividing a base substrate; and a battery electrode formed on the unit substrate to have conductivity. The battery electrode includes a lower battery electrode and an upper battery electrode formed on one surface and the other surface of the unit substrate, respectively. One of the upper battery electrode and the lower battery electrode may be formed in an uncured state.

[0024] Beneficial Effects

[0025] According to the present invention, the following effects can be obtained.

[0026] The implementation of the present invention can omit a series of processes for distributing and injecting bonding materials, thereby reducing the time required to manufacture solar cells.

[0027] The implementation of the present invention can fundamentally prevent the power generation efficiency of the solar cell from being reduced due to the resistance of the bonding material, thereby improving the quality of the finished solar cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 FIG. 4 is a schematic front view of a solar cell according to the present invention.

[0029] Figure 2 FIG. 1 is a schematic front view of a unit battery according to the present invention.

[0030] Figure 3 A front view schematically shows the shape of a first unit cell joined to a second unit cell in a solar cell of the present invention.

[0031] Figure 4 A front view schematically shows the shape of a first unit cell before being joined to a second unit cell in an example of a solar cell of the present invention.

[0032] Figure 5 A front view schematically shows the shape of a solar cell after a first unit cell is joined to a second unit cell in an example of the present invention.

[0033] Figure 6 A three-dimensional schematic diagram showing that the first bonding electrode and the first non-bonding electrode are formed in the first upper cell electrode in the solar cell of the present invention is shown.

[0034] Figure 7 A three-dimensional schematic diagram showing that the second bonding electrode and the second non-bonding electrode are formed in the second lower cell electrode in the solar cell of the present invention is shown.

[0035] Figure 8 A front view schematically shows the shape of the second bonding electrode before bonding to the first bonding electrode in the solar cell of the present invention.

[0036] Fig. 9 A front view schematically shows the shape of an inserting member inserted into an inserting groove when the second bonding electrode is bonded to the first bonding electrode in the solar cell of the present invention.

[0037] Fig. 10A It is a front view schematic diagram of a substrate preparation process of the method for manufacturing a solar cell according to the present invention.

[0038] Fig. 10B It is a front view schematic diagram of a first electrode forming process of the method for manufacturing a solar cell according to the present invention.

[0039] Fig. 10C FIG. 4 is a front view schematically showing a first curing process of the method for manufacturing a solar cell according to the present invention.

[0040] Fig. 10D The figure is a front view schematic diagram of a second electrode forming process of the method for manufacturing a solar cell according to the present invention.

[0041] Fig. 10E It is a front view schematic diagram of a dividing process of the method for manufacturing a solar cell according to the present invention. DETAILED DESCRIPTION

[0042] The following embodiments described with reference to the accompanying drawings illustrate the advantages and features of the present invention and how to implement them. However, the present invention can be embodied in different forms and should not be limited to the embodiments listed. Instead, these embodiments are provided to make the present invention more complete and to enable those skilled in the art to fully understand the scope of the present invention. In addition, the present invention is limited only by the scope of the claims.

[0043] The shapes, sizes, proportions, angles and quantities disclosed in the drawings used to describe the embodiments of the present invention are for illustrative purposes only and are not intended to limit the present invention. In this article, the same reference numerals represent the same elements. In the following, some detailed descriptions will be appropriately omitted to avoid unnecessary obscurity of the key points of the present invention. The use of "including", "comprising" and "having" is an open-ended term unless specifically described as "only including", "only comprising" or "only having". In addition, any word mentioned should include the singular or plural, unless otherwise defined.

[0044] Even if not explicitly stated, it should be understood that the described elements may contain acceptable errors or manufacturing tolerances.

[0045] When describing a positional relationship, for example, when describing that one component is located "on", "below", "beside", etc., another component, it should be understood that there is the possibility of another object being located between the two components, unless it is explicitly stated that one component is "directly" located "on", "below", "beside" another component.

[0046] When describing a temporal relationship, for example, when using “after,” “next,” or “before,” the possibility that the two events are not sequential should be included, unless it is explicitly stated that one event occurs “directly after” or “before” the other.

[0047] It is understood that although the terms "first", "second", etc. are used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish between elements. Without departing from the scope of the present invention, the first element may also be referred to as the second element, and the second element may also be referred to as the first element.

[0048] Those skilled in the art will fully appreciate that the features of the various embodiments of the present invention may be used in combination in part or in whole. The embodiments of the present invention may be implemented individually or interdependently.

[0049] Hereinafter, a solar cell 1 according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. The unit cell 10 according to the present invention is included in the solar cell 1 according to the present invention, and thus will be described together with the introduction of the embodiment of the solar cell 1. Figures 1 to 10E The hatching and dots are only used to distinguish different components and not to represent cross sections.

[0050] See also Figure 1 The solar cell 1 according to the present invention can convert the light energy of sunlight into electrical energy. The solar cell 1 according to the present invention can be a wafer-type solar cell and a thin-film solar cell. The following will describe an implementation in which the solar cell 1 according to the present invention is a wafer-type solar cell, but those skilled in the art can also implement the solar cell 1 according to the present invention as a thin-film solar cell based on this.

[0051] See also Figure 1 The solar cell 1 according to the present invention can be manufactured into a module type in which a plurality of unit cells 10 are joined to each other. Each unit cell 10 is composed of a divided (or separated) base substrate 100 (such as Fig. 10DIn the solar cell 1 according to the present invention, the base substrate 100 may be in a state before being divided into unit cells 10. The base substrate 100 includes a substrate 110 (such as Fig. 10A ), a first base electrode 130 (as shown) formed on a surface 110a of the substrate 110 Fig. 10B ), and a second substrate electrode 140 (as shown) formed on the other surface 110b of the substrate 110 Fig. 10D ). Figure 1 In the figure, the solar cell 1 according to the present invention may have five unit cells 10, 10', 10", 10'" and 10"", but this is only an example, and the solar cell 1 according to the present invention may also include two to four unit cells 10 or six to more unit cells 10. Except for the different positions, these unit cells 10 may be substantially the same.

[0052] See also Figure 1 and 2 The unit cells 10 may each include a unit substrate 11 and a cell electrode 12 .

[0053] The unit substrate 11 can be formed by dividing the base substrate 100 (eg Fig. 10D The unit substrate 11 may have a certain conductive polarity. The number of unit substrates 11 may be equal to the number of blocks formed by dividing one base substrate 100. For example, when the base substrate 100 is divided into five blocks, the unit substrates 11 may be five blocks. The unit substrate 11 may be a substrate 110 (such as Fig. 10A shown).

[0054] The battery electrode 12 may be formed on the unit substrate 11. The battery electrode 12 may have electrical conductivity. The battery electrode 12 may be made of a metal material having good electrical conductivity, such as Ag, Al, Ag+Al, Ag+Mg, Ag+Mn, Ag+Sb, Ag+Zn, Ag+Mo, Ag+Ni, Ag+Cu, or Ag+Al+Zn.

[0055] The battery electrode 12 may include a lower battery electrode 121 and an upper battery electrode 122 .

[0056] The lower battery electrode 121 is formed on a surface 11a of the unit substrate 11. The surface 11a of the unit substrate 11 may be a downward surface of the unit substrate 11 of the solar cell 1, which is slightly lowered toward the height. The surface 11a of the unit substrate 11 may be an upward surface of the unit substrate 11, and the upward direction is opposite to the downward direction. The lower battery electrode 121 may be a first substrate electrode 130 (e.g., Fig. 10B An electrode as shown).

[0057] The upper battery electrode 122 is formed on the other surface 11b of the unit substrate 11. If the one surface 11a of the unit substrate 11 is the surface of the unit substrate 11 in the downward direction, the other surface 11b of the unit substrate 11 is the surface of the unit substrate 11 in the upward direction. Hereinafter, examples of "one surface" and "the other surface" being the downward and upward surfaces of a specific element will be described. In addition, the terms "upper" and "lower" used in this article are used to distinguish between elements, and are not used to indicate a specific direction. The upper battery electrode 122 can be a second substrate electrode 140 (such as Fig. 10D An electrode as shown).

[0058] At least one of the upper battery electrode 122 and the lower battery electrode 121 may be formed in an uncured state PC. Therefore, the solar cell 1 according to the present invention can achieve a bonding force for bonding the unit cell 10 by means of an electrode having an uncured state PC. The uncured state PC is a state in which the electrode has a bonding force. The electrodes 121 and 122 have mobility in the uncured state PC. When one of the upper battery electrode 122 and the lower battery electrode 121 is in a cured state HC, the other may be formed in an uncured state PC. Even in this case, the solar cell 1 according to the present invention can achieve a bonding force for bonding the unit cell 10 by means of an electrode having an uncured state PC. The cured state HC is a state in which the electrode does not have a bonding force. The electrodes 121 and 122 do not have mobility in the cured state HC and have a certain appearance.

[0059] See also Figures 3 to 9 The solar cell 1 according to the present invention may include a first unit cell 2 and a second unit cell 3 .

[0060] The first unit cell 2 may be one of the unit cells 10. The first unit cell 2 is made by dividing one of the plurality of blocks formed by the base substrate 100. The electric energy generated by the solar cell 1 according to the present invention may be transferred to the second unit cell 3 through the first unit cell 2.

[0061] See also Figure 3 The first unit battery 2 may include a first unit substrate 21 and a first battery electrode 22 .

[0062] The first unit substrate 21 may be a substrate 110 (eg Fig. 10A The first unit substrate 21 may be formed by dividing the base substrate 100. The first unit substrate 21 may have a certain degree of conductive polarity.

[0063] The first battery electrode 22 may be formed on the first unit substrate 21. The first battery electrode 22 may be formed on each of the one surface 21a and the other surface 21b of the first unit substrate 21. The first battery electrode 22 may have conductivity. The first battery electrode 22 may be made of a material such as Ag, Al, Ag+Al, Ag+Mg, Ag+Mn, Ag+Sb, Ag+Zn, Ag+Mo, Ag+Ni, Ag+Cu, or Ag+Al+Zn.

[0064] The first battery electrode 22 may include a first lower battery electrode 221 and a first upper battery electrode 222 .

[0065] The first lower battery electrode 221 is formed on a surface 21a of the first unit substrate 21. The first lower battery electrode 221 may be formed on a surface 21a of the first unit substrate 21 disposed in a downward direction. The first lower battery electrode 221 may be a first base electrode 130 (eg, Fig. 10B The first lower battery electrode 221 may be formed in one state of a cured state HC and an uncured state PC.

[0066] The first upper battery electrode 222 is formed on the other surface 21b of the first unit substrate 21. The first upper battery electrode 222 may be formed on the other surface 21b of the first unit substrate 21 disposed in an upward direction. The first upper battery electrode 222 may be a second substrate electrode 140 (eg, Fig. 10D The first upper battery electrode 222 may be formed in a state different from the first lower battery electrode. For example, when the first lower battery electrode 221 is formed in the cured state HC, the first upper battery electrode 222 may be formed in the uncured state PC. When the first lower battery electrode 221 is in the uncured state PC, the first upper battery electrode 222 may be formed in the cured state HC.

[0067] The second unit cell 3 may be one unit cell coupled to the first unit cell 2 among the unit cells 10. The second unit cell 3 may be coupled to the first unit cell 2 in an upward direction of the first unit cell 2. The second unit cell 3 is made of one of the plurality of pieces formed by dividing the base substrate 100.

[0068] The second unit cell 3 may include a second unit substrate 31 and a second cell electrode 32 .

[0069] The second unit substrate 31 may be a substrate 110 (eg Fig. 10A The second unit substrate 31 may be formed by dividing the base substrate 100 (as shown in FIG. Fig. 10D The second unit substrate 31 may have a certain degree of electrical conductivity.

[0070] The second battery electrode 32 is formed on the second unit substrate 31. The second battery electrode 32 may be formed on each of the one surface 31a and the other surface 31b of the second unit substrate 31. The second battery electrode 32 may have conductivity. The second battery electrode 32 may be made of a material such as Ag, Al, Ag+Al, Ag+Mg, Ag+Mn, Ag+Sb, Ag+Zn, Ag+Mo, Ag+Ni, Ag+Cu, or Ag+Al+Zn.

[0071] The second battery electrode 32 and the first battery electrode 22 can be bonded to each other without a bonding material, and thus the second unit cell 3 can be coupled to the first unit cell 2. That is, when the second battery electrode 32 and the first battery electrode 22 are bonded to each other, the second unit cell 3 can be coupled to the first unit cell 2. Therefore, the solar cell 1 according to the present invention can achieve the following effects:

[0072] First, the solar cell 1 according to the present invention can bond the unit cells 2 and 3 to each other via the cell electrodes 22 and 32. Therefore, compared with the prior art in which the unit cells 10 are bonded to each other by using a bonding material, a series of processes for dispensing the bonding material can be omitted in the process of manufacturing the solar cell 1 according to the present invention. Therefore, the solar cell 1 according to the present invention can be shortened in manufacturing time, thereby improving the productivity of the solar cell.

[0073] Secondly, the solar cell 1 according to the present invention can make the unit cells 2 and 3 bonded to each other without using bonding materials, so the generated electric energy does not need to pass through the bonding materials. Therefore, the solar cell 1 according to the present invention can fundamentally prevent the power generation efficiency of the solar cell from being reduced due to the resistance of the bonding materials, thereby improving the quality of the finished solar cell.

[0074] The second battery electrode 32 and the first battery electrode 22 may be made of the same material and thus may be bonded to each other. For example, the second battery electrode 32 and the first battery electrode 22 may both be made of Ag material. Therefore, the solar cell 1 according to the present invention can reduce its internal resistance. This is because in the process of energy transfer to the first battery electrode 22 and the second battery electrode 32, the energy can be reduced more by passing through the same material than by passing through different materials. Therefore, the solar cell 1 according to the present invention can further increase the power generation efficiency of the solar cell.

[0075] The second battery electrode 32 may include a second lower battery electrode 321 and a second upper battery electrode 322 .

[0076] The second lower battery electrode 321 is formed on a surface 31a of the second unit substrate 31. The second lower battery electrode 321 may be formed on a surface 31a of the second unit substrate 31 disposed in a downward direction. The second lower battery electrode 321 may be one electrode of the first base electrode 130. The second lower battery electrode 321 may be formed in one of a cured state HC and an uncured state PC.

[0077] The second upper battery electrode 322 is formed on the other surface 31b of the second unit substrate 31. The second upper battery electrode 322 may be formed on the other surface 31b of the second unit substrate 31 disposed in the upward direction. The second upper battery electrode 322 may be one electrode of the second base electrode 140. When the second lower battery electrode 321 is in the cured state HC, the second upper battery electrode 322 may be formed in the uncured state PC. When the second lower battery electrode 321 is in the uncured state PC, the second upper battery electrode 322 may be formed in the cured state HC.

[0078] The solar cell 1 according to the present invention can be Figure 3 The second lower battery electrode 321 and the first upper battery electrode 222 are bonded to each other, thereby coupling the second unit cell 3 to the first unit cell 2. Hereinafter, an example in which the second lower battery electrode 321 is bonded to the first upper battery electrode 222 to couple the second unit cell 3 to the first unit cell 2 will be described, but this is only an example, and the second unit cell 3 may be coupled to the first unit cell 2 when the second upper battery electrode 322 and the first lower battery electrode 221 are bonded to each other.

[0079] At least one of the second lower battery electrode 321 and the first upper battery electrode 222 may be formed in the uncured state PC. Therefore, the solar cell 1 according to the present invention can generate a bonding force for coupling the unit cells 2 and 3. For example, all of the second lower battery electrodes 321 and the first upper battery electrodes 222 may be formed in the uncured state PC, so the second unit cell 3 may be coupled to the first unit cell 2. When at least one of the second lower battery electrode 321 and the first upper battery electrode 222 is formed in the uncured state PC, the other may be formed in the cured state HC, so the second unit cell 3 may be coupled to the first unit cell 2.

[0080] See also Figure 4 and 5, the first upper battery electrode 222 can be formed in the uncured state PC, so the second lower battery electrode 321 can be bonded thereto, reducing its thickness. Therefore, in the solar cell 1 according to the present invention, its total thickness can be reduced, and thus the movement distance of the generated energy is also shortened. Therefore, the solar cell 1 according to the present invention can reduce its total resistance. The thickness can be a length relative to the first axial direction (X-axis direction), which corresponds to a direction parallel to the upward direction and the downward direction, and is the same as the direction in which the second unit cell 3 is spaced apart from the first unit cell 2. Although not shown, the second lower battery electrode 321 can be formed in the uncured state PC, so the first upper battery electrode 222 can be bonded thereto, reducing its thickness. The second lower battery electrode 321 and the first upper battery electrode 222 can be bonded to each other, and thus can be formed to have the same thickness.

[0081] For example, if Figure 4 and 5 As shown, when the first upper battery electrode 222 has a first thickness D1 and the second lower battery electrode 321 has a second thickness D2, the third thickness D3 formed by the second lower battery electrode 321 and the first upper battery electrode 222 may have a value smaller than the sum of the first thickness D1 and the second thickness D2. This is because at least one of the first upper battery electrode 222 and the second lower battery electrode 321 is formed in the uncured state PC. Therefore, the solar cell 1 according to the present invention can reduce its total thickness. The third thickness D3 may be the spacing distance between the second unit cell 3 and the first unit cell 2 relative to the first axial direction (X-axis direction). Figure 4 In the embodiment, the first upper battery electrode 222 may be formed in the uncured state PC, but this is only an example, and the third thickness D3 may be reduced when the second lower battery electrode 321 is formed in the uncured state PC.

[0082] When at least one of the second lower battery electrode 321 and the first upper battery electrode 222 is formed in the uncured state PC, as Figure 5 As shown, the second lower battery electrode 321 and the first upper battery electrode 222 may be arranged to partially overlap in the first axial direction (X-axis direction). Therefore, the overall thickness of the solar cell 1 according to the present invention may be reduced.

[0083] Hereinafter, the patterns of the first upper battery electrode 222 and the second lower battery electrode 321 will be described with reference to the accompanying drawings. When the second unit cell 3 is coupled to the first unit cell 2 when the second upper battery electrode 322 and the first lower battery electrode 221 are engaged with each other, the first lower battery electrode 221 may be implemented to be substantially equivalent to the second lower battery electrode 321 described below, and the second upper battery electrode 322 may be implemented to be substantially equivalent to the first upper battery electrode 222.

[0084] See also Figure 6, the first upper battery electrode 222 may include a first bonding electrode 2221 .

[0085] The second lower battery electrode 321 is bonded to the first bonding electrode 2221. The first bonding electrode 2221 may be one electrode of the first upper battery electrode 222 bonded to the second lower battery electrode 321. The first bonding electrode 2221 may be coupled to the first unit substrate 21. The first bonding electrode 2221 may be formed in a cured state HC.

[0086] The first bonding electrode 2221 may include a first bonding surface 1A and an insertion groove G.

[0087] The first joint surface 1A (such as Figure 8 1A) may be a surface of the first bonding electrode 2221 facing the second lower battery electrode 321. In this case, the other surface of the first bonding electrode 2221 may face the first unit substrate 21. The second lower battery electrode 321 may be bonded to the first bonding surface 1A.

[0088] The insertion groove G is formed in the first joint surface 1A. The insertion groove G may be formed by a process of forming a groove of a certain depth in the first joint surface 1A. The insertion groove G may have the same size as the first upper battery electrode 222 in the first axial direction (X-axis direction). Figure 6 Fourteen insertion grooves G are shown to be formed on the first joint surface 1A, but this is merely an illustration, and one to thirteen insertion grooves G or fifteen or more insertion grooves G may be formed on the first joint surface 1A.

[0089] See also Figure 6 , the first bonding electrode 2221 may include a first bonding finger 1F.

[0090] The first bonding finger 1F can move the energy generated from the first unit substrate 21 to the second lower battery electrode 321. An insertion groove G is provided on the inner side of the first bonding finger 1F. The first bonding finger 1F may include a first bonding finger formed along a second axial direction (Y-axis direction) and a second bonding finger formed along a third axial direction (Z-axis direction), wherein the third axial direction (Z-axis direction) is perpendicular to the second axial direction (Y-axis direction). The second bonding finger and the first bonding finger may be coupled. The second bonding finger and the first bonding finger may surround the insertion groove G. For example, two second bonding fingers and two first bonding fingers may be arranged outside the insertion groove G. Alternatively, one second bonding finger and two first bonding fingers may be arranged outside the insertion groove G. Figure 6 Three first engagement fingers and twelve second engagement fingers are shown. The second axial direction (Y-axis direction) may be a direction perpendicular to the first axial direction (X-axis direction). The third axial direction (Z-axis direction) may be a direction perpendicular to the second axial direction (Y-axis direction) and the first axial direction (X-axis direction).

[0091] See also Figure 6 , the first upper battery electrode 222 may include a first non-bonding electrode 2222.

[0092] The first non-bonding electrode 2222 is coupled to the first bonding electrode 2221. The first non-bonding electrode 2222 may be coupled to the first bonding electrode 2221 and may move energy generated by the first unit substrate 21 to the first bonding electrode 2221. The first non-bonding electrode 2222 may be one electrode of the first upper battery electrode 222 that is not bonded to the second lower battery electrode 321. The first non-bonding electrode 2222 may be coupled to the first unit substrate 21. The first non-bonding electrode 2222 may be formed in a solidified state HC to have the same state as the first bonding electrode 2221.

[0093] The first non-bonding electrode 2222 may include a plurality of first non-bonding fingers 10F spaced apart from each other. The first non-bonding fingers 10F may be spaced apart from each other in the second axial direction (Y-axis direction). The first non-bonding fingers 10F may extend in the third axial direction (Z-axis direction). The first non-bonding fingers 10F may have a linear shape in the third axial direction (Z-axis direction). The first non-bonding fingers 10F may be coupled to the first bonding electrode 2221. The first non-bonding fingers 10F may move the generated energy to the first bonding electrode 2221. Figure 6 Three first non-engaging fingers 10F are depicted.

[0094] See also Figures 7 to 9 , the second lower battery electrode 321 may include a second bonding electrode 3211 .

[0095] The second bonding electrode 3211 is bonded to the first bonding electrode 2221. The second bonding electrode 3211 may be one electrode of the second lower battery electrode 321 bonded to the first bonding electrode 2221. The second bonding electrode 3211 may be coupled to the second unit substrate 31. The second bonding electrode 3211 may be formed in an uncured state PC.

[0096] See also Figure 7 and 8 , the second bonding electrode 3211 may include a second bonding surface 2A.

[0097] The second bonding surface 2A may be a surface of the second bonding electrode 3211 facing the first upper battery electrode 222. The other surface of the second bonding electrode 3211 may face the second unit substrate 31. The second bonding surface 2A may be bonded to the first bonding electrode 2221. The second bonding surface 2A may have a flat shape before the second bonding electrode 3211 and the first bonding electrode 2221 are bonded to each other. That is, before the second bonding electrode 3211 and the first bonding electrode 2221 are bonded to each other, the second bonding surface 2A may have a flat shape without curvature.

[0098] See also Fig. 9 , the second bonding electrode 3211 may include an insert I.

[0099] The insert I may be inserted into the insertion groove G when the second bonding electrode 3211 is bonded to the first bonding electrode 2221. Therefore, the solar cell 1 according to the present invention may enable the first bonding electrode 2221 to support the second bonding electrode 3211. Therefore, the solar cell 1 according to the present invention may enhance the bonding force between the second bonding electrode 3211 and the first bonding electrode 2221, thereby increasing the coupling force between the first unit cell 2 and the second unit cell 3. The insert I may be in an uncured state PC and may be inserted into the insertion groove G. The insert I may have a shape corresponding to the insertion groove G. The second bonding electrode 3211 may include a plurality of inserts I, the number of which is equal to the number of the insertion grooves G.

[0100] It has been described above that the first bonding electrode 2221 includes the insertion groove G and the second bonding electrode 3211 includes the insert I, but it is understandable that this is only an example, and the first bonding electrode 2221 may include the insert I and the second bonding electrode 3211 may include the insertion groove G.

[0101] See also Figures 7 to 9 , the second lower battery electrode 321 may include a second non-bonding electrode 3212 .

[0102] The second non-bonding electrode 3212 is coupled to the second bonding electrode 3211. The second non-bonding electrode 3212 may be coupled to the second bonding electrode 3211 and may be used to move energy generated by the second unit substrate 31. The second non-bonding electrode 3212 may be an electrode of the second lower battery electrode 321 that is not bonded to the first upper battery electrode 222. The second non-bonding electrode 3212 may be coupled to the second unit substrate 31. The second non-bonding electrode 3212 may be formed in an uncured state PC and have the same state as the second bonding electrode 3211.

[0103] The second non-bonding electrode 3212 may include a plurality of second non-bonding fingers 20F spaced apart from each other. The second non-bonding fingers 20F may be spaced apart from each other in the second axial direction (Y-axis direction). The second non-bonding fingers 20F may extend in the third axial direction (Z-axis direction). The second non-bonding fingers 20F may be coupled to the second bonding electrode 3211. The second non-bonding fingers 20F may be used to move the energy generated by the second unit substrate 31. Figure 7 Three second non-engaging fingers 20F are depicted.

[0104] Hereinafter, an embodiment of the method for manufacturing a solar cell according to the present invention will be described below with reference to the accompanying drawings. The method for manufacturing a solar cell according to the present invention can be used to manufacture the solar cell 1 according to the present invention.

[0105] See also Fig. 10A , the method for manufacturing a solar cell according to the present invention may include a substrate preparation process.

[0106] The substrate preparation process is a process for preparing a substrate 110 in which a plurality of partitions 120 for dividing the substrate 110 into a plurality of pieces are formed. The substrate preparation process may be performed by a substrate loading device (not shown) that can load the substrate 110 into a processing space (not shown) for use in manufacturing solar cells. The processing space may be used as a chamber as a whole to accommodate a plurality of manufacturing devices required for manufacturing solar cells.

[0107] The substrate 110 may have a certain degree of conductive polarity. For example, the substrate 110 may be composed of an N-type silicon wafer or a P-type silicon wafer. Although not shown, a surface 110a of the substrate 110 may be formed into a concave-convex structure. The substrate 110 may include a bottom surface disposed in a downward direction, a top surface disposed in an upward direction, and a side surface 110c connecting the top surface and the bottom surface of the substrate 110. In this case, a surface 110a of the substrate 110 may correspond to one of the bottom surface of the substrate 110, the top surface of the substrate 110, and the side surface 110c of the substrate 110. For example, if a surface 110a of the substrate 110 corresponds to the bottom surface of the substrate 110, the other surface 110b of the substrate 110 corresponds to the top surface of the substrate 110. In this example, each of the plurality of thin film layers formed on the one surface 110a of the substrate 110 and the other surface 110b of the substrate 110 may be formed into a concave-convex structure.

[0108] The partition 120 is used to divide the substrate 110 into multiple pieces. The partition 120 can be formed on a surface 110a of the substrate 110. The partition 120 can be formed by machining a groove of a certain depth on a surface 110a of the substrate 110 through a scoring process. The scoring process can be performed by a scoring device (not shown) that can irradiate a laser on the substrate 110 to remove a portion of the substrate 110. Fig. 10AIn the embodiment, the scoring process is performed on one surface 110a of the substrate 110, but this is only an example, and the scoring process may also be performed on the other surface 110b of the substrate 110. In addition, in this article, the partition 120 is formed by using the scoring process as an example, but this is only an example, and the partition 120 may be formed by a process of wet etching the substrate 110 to form an etching groove (not shown), a dry etching process, or a process using a mask. In the case where the substrate 110 is divided into five pieces, as shown in FIG. Fig. 10A As shown, four partitions 120 may be formed on a surface 110 a of the substrate 110 .

[0109] Although not shown, one or more thin film layers may be formed on the substrate 110. Hereinafter, examples of thin film layers formed on the substrate 110 will be described.

[0110] First, a first thin film layer may be formed on the substrate 110. The process of forming the first thin film layer may be performed after the scratching process. The first thin film layer may be a semiconductor layer formed as a thin film type on the substrate 110. The first thin film layer may form a PN junction with the substrate 110. Therefore, in the case where the substrate 110 is formed of an N-type silicon wafer, the first thin film layer may be a P-type semiconductor layer. The first thin film layer may be formed by a process such as chemical vapor deposition (CVD). The first thin film layer may be formed as a PIN structure in which a P-type semiconductor material, an I-type semiconductor material, and an N-type semiconductor material are stacked in sequence. As described above, when the first thin film layer is formed as a PIN structure, the I-type semiconductor material is depleted by the P-type semiconductor material and the N-type semiconductor material, and therefore, an electric field is generated therein, and holes and electrons generated by sunlight drift due to the electric field and are collected in the P-type semiconductor material and the N-type semiconductor material. In the case where the first thin film layer is formed in a PIN structure, it is preferred to form a P-type semiconductor material in the first thin film layer, and then form an I-type semiconductor material and an N-type semiconductor material. The reason is that since the drift mobility of holes is generally lower than that of electrons, the P-type semiconductor material is formed close to the light-receiving surface, thereby improving the collection efficiency of incident light. The method for manufacturing a solar cell according to the present invention may form a first thin film layer to have a stacked structure. For example, the method for manufacturing a solar cell according to the present invention may form a first thin film layer to have a stacked structure of a series type (PIN / PIN) or a three-layer type (PIN / PIN / PIN). The first thin film layer may be formed on at least one of a surface 110a, another surface 110b, and a side surface of the substrate 110, or may be formed on each of a surface 110a, another surface 110b, and a side surface of the substrate 110.

[0111] Next, a second thin film layer is formed on the first thin film layer. The process of forming the second thin film layer may be performed after the process of forming the first thin film layer. The second thin film layer may be a transparent conductive layer. For example, the second thin film layer may be a transparent conductive oxide (TCO) layer. The second thin film layer may protect the first thin film layer, collect carriers such as holes (+) generated in the substrate 110, and move the collected carriers in an upward direction. The second thin film layer may be composed of a transparent conductive material such as indium tin oxide (ITO), ZnOH, ZnO:B, ZnO:Al, SnO 2 or SnO 2 :F. The second thin film layer can be formed of a transparent conductive material such as ZnO, ZnO:B, ZnO:Al or Ag by a sputtering process or a metal organic chemical vapor deposition (MOCVD) process. The second thin film layer has the ability to scatter sunlight to propagate at multiple angles, thereby increasing the ratio of light re-incident to the first thin film layer.

[0112] Next, the third thin film layer is formed on the second thin film layer. The process of forming the third thin film layer may be performed after the process of forming the second thin film layer. In the case where the third thin film layer is formed on the second thin film layer, the first thin film layer may be an intrinsic semiconductor layer, the second thin film layer may be a semiconductor layer, and the third thin film layer may be a transparent conductive layer. In this case, the plurality of thin film layers may be formed by a plasma enhanced chemical vapor deposition (PECVD) process and a sputtering process.

[0113] The method for manufacturing a solar cell according to the present invention can selectively form the first thin film layer, the second thin film layer and the third thin film layer. That is, the method for manufacturing a solar cell according to the present invention can form one or more of the first thin film layer, the second thin film layer and the third thin film layer, or not form all of the first thin film layer, the second thin film layer and the third thin film layer.

[0114] See also Fig. 10B , the method for manufacturing a solar cell according to the present invention may include a first electrode forming process.

[0115] The first electrode forming process is a process of forming a plurality of first substrate electrodes 130 having conductivity on a surface 110a of the substrate 110. The first electrode forming process may be performed after the substrate preparation process. The first substrate electrodes 130 formed by performing the first electrode forming process may be made of materials such as Ag, Al, Ag+Al, Ag+Mg, Ag+Mn, Ag+Sb, Ag+Zn, Ag+Mo, Ag+Ni, Ag+Cu or Ag+Al+Zn. Fig. 10B In the embodiment, the first electrode forming process is performed on one surface 110 a of the substrate 110 , but this is only an example, and the first electrode forming process may also be performed on another surface 110 b of the substrate 110 .

[0116] See also Fig. 10C , the method for manufacturing a solar cell according to the present invention may include a first curing process.

[0117] The first curing process is a process of curing the first substrate electrode 130. The first curing process may be performed after the first electrode forming process. The first curing process may be performed by a heating device (not shown) that can heat the first substrate electrode 130. When the first curing process is performed, the first substrate electrode 130 may be formed in a cured state HC.

[0118] See also Fig. 10D , the method for manufacturing a solar cell according to the present invention may include a second electrode forming process.

[0119] The second electrode forming process is a process of forming a plurality of second base electrodes 140 having conductivity and an uncured state PC on the other surface 110b of the substrate 110. The second electrode forming process may be performed after the first electrode forming process. The second base electrodes 140 formed by performing the second electrode forming process may be made of materials such as Ag, Al, Ag+Al, Ag+Mg, Ag+Mn, Ag+Sb, Ag+Zn, Ag+Mo, Ag+Ni, Ag+Cu or Ag+Al+Zn. Fig. 10D In the embodiment, the second electrode forming process is performed on the other surface 110 b of the substrate 110 , but this is only an example, and the second electrode forming process may also be performed on the one surface 110 a of the substrate 110 .

[0120] The method of manufacturing a solar cell according to the present invention may not include a process of curing the second substrate electrode 140 after performing the second electrode forming process. Therefore, the method of manufacturing a solar cell according to the present invention may achieve a bonding force capable of bonding the unit cell 10 through the second substrate electrode 140 having an uncured state PC.

[0121] See also Fig. 10E , the method for manufacturing a solar cell according to the present invention may include a dividing process.

[0122] The dividing process is a process of dividing the substrate 110 into a plurality of pieces through the partition 120 to form a unit cell 10. That is, the dividing process is a process of dividing the base substrate 100 through the partition 120 to form a plurality of unit cells 10. The dividing process may be performed by a dividing device (not shown), which may apply an external force, such as a bending force, to the base substrate 100. The dividing process may be performed after the second electrode forming process. In the case of dividing the base substrate 100 into N (where N is an integer of 2 or greater) unit cells 10, the dividing process may be performed N-1 times. For example, Fig. 10EAs shown, in the case of dividing the base substrate 100 into five unit cells 10 , the dividing process may be performed four times.

[0123] Please refer again Figure 1 , the method for manufacturing a solar cell according to the present invention may include a bonding process.

[0124] The bonding process is a process of bonding the unit cells 10 through the second base electrode 140 having an uncured state PC. The bonding process may be performed by a bonding device (not shown) that can move and bond the divided unit cells 10. The bonding process may be performed after the dividing process. In the case where the base substrate 100 is divided into N unit cells 10, the bonding process may be performed N-1 times. For example, Fig. 10E As shown, in the case where the base substrate 100 is divided into five unit cells 10 , the bonding process may be performed four times.

[0125] Although not shown, the method for manufacturing a solar cell according to the present invention may include a second curing process.

[0126] The second curing process is a process for curing the bonded unit cells 10. The second curing process may be performed by a heating device (not shown). The second curing process may be performed after the bonding process. When performing the second curing process, the solar cell 1 according to the present invention may be manufactured in a module form in which the unit cells 10 are bonded to each other.

[0127] The present invention described above is not limited to the above embodiments and drawings, and those skilled in the art will appreciate that various changes, modifications and substitutions may be made without departing from the spirit and scope of the present invention.

Claims

1. A method for manufacturing a solar cell, the method comprising: A substrate preparation process for preparing a substrate in which a plurality of partitions for dividing the substrate into a plurality of pieces are formed; A first electrode forming process is used to form a plurality of first base electrodes having conductivity on a first surface of the substrate; A first curing process for curing the first substrate electrode; A second electrode forming process for forming a plurality of second base electrodes having conductivity and in an uncured state on a second surface of the substrate; a dividing process for dividing the substrate into a plurality of pieces by the separator to form a plurality of unit cells, the plurality of unit cells including a first unit cell and a second unit cell, the first unit cell and the second unit cell each including a first cell electrode in a cured state and a second cell electrode in an uncured state; as well as a bonding process for bonding the first unit cell and the second unit cell by the first battery electrode of the first unit cell and the second battery electrode of the second unit cell without a bonding material, the first unit cell and the second unit cell partially overlapping each other, The first battery electrode of the first unit battery includes an insertion groove, and the second battery electrode of the second unit battery includes an inserter, and when the first battery electrode in a cured state and the second battery electrode in an uncured state are joined to each other, the inserter is inserted into the insertion groove.

2. The method according to claim 1, further comprising: The second curing process is used to cure the bonded unit cells. 3 . The method of claim 1 , wherein a thickness of the second battery electrode decreases as the second battery electrode is joined to the first battery electrode.

4. The method of claim 1, wherein: The first battery electrode is formed to have a first thickness, the second battery electrode is formed to have a second thickness, When the second battery electrode and the first battery electrode are joined to each other, a third thickness between the first unit cell and the second unit cell has a value smaller than a sum of the second thickness and the first thickness. 5 . The method of claim 1 , wherein the second battery electrode and the first battery electrode partially overlap each other in a first axial direction, and the second unit cell and the first unit cell are spaced apart from each other in the first axial direction. The method of claim 1 , wherein the second battery electrode has the same thickness as the first battery electrode.

7. The method of claim 1, wherein the first battery electrode and the second battery electrode are made of the same material and are bonded to each other.

8. The method of claim 1, wherein: The first battery electrode includes a first bonding electrode, the first bonding electrode is bonded to the second battery electrode, The first bonding electrode includes a first bonding surface facing the second battery electrode and the insertion groove formed in the first bonding surface.

9. The method of claim 8, wherein: The first bonding electrode further comprises a first bonding finger, the inner side of which is provided with the insertion groove. The first joint finger includes a first joint finger and a second joint finger. The direction formed by the first joint finger is perpendicular to the direction in which the first unit battery and the second unit battery are spaced from each other. The second joint finger is coupled to the first joint finger.

10. The method of claim 8, wherein: The first battery electrode includes a first non-bonding electrode coupled to the first bonding electrode. The first non-bonded electrode includes a plurality of first non-bonded fingers spaced apart from each other.

11. The method of claim 8, wherein: The second battery electrode includes a second bonding electrode, the second bonding electrode is bonded to the first bonding electrode, The second bonding electrode comprises a second bonding surface facing the first bonding electrode, The second bonding surface has a flat shape before the second bonding electrode and the first bonding electrode are bonded to each other.

12. The method of claim 8, wherein: The second battery electrode includes a second bonding electrode bonded to the first bonding electrode, The second bonding electrode includes the insert, which is bonded to the first bonding electrode and inserted into the insertion groove.

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