Method for forming electrode of solar cell module and solar cell module utilizing same

Abstract

One embodiment of the present invention relates to a method for forming an electrode of a solar cell module and a solar cell module utilizing same. The method for forming an electrode of a solar cell module comprises: a step for forming an electrode on a solar cell; and a step for disposing a conductive member on the electrode, wherein the conductive member is applied on the electrode so as to have a smaller width than the electrode in one direction. The solar cell module provides a buffering effect and an electrical connection between the solar cell and the conductive member, and can prevent delamination of solar cell layers caused by differences in thermal expansion coefficient between layers.

Description

Method for forming electrodes of a solar cell module and a solar cell module applying the same

[0001] The present invention relates to a method for forming electrodes and a solar cell module to which the same is applied.

[0002] The tabbing process of crystalline solar cell modules was able to achieve high adhesion through physical bonding by applying heat to solder-coated wires, thereby soldering the cell electrodes and the wire's coating material.

[0003] However, the tabbing process for perovskite solar cell modules is conducted at low temperatures due to the performance degradation of perovskite caused by heat. Since conventional solder does not melt at low temperatures, the process is carried out by additionally using ECA (Electrically Conductive Adhesive) adhesive to bond and electrically connect the wires at low temperatures.

[0004] Specifically, when tabbing is performed using ECA on a perovskite solar cell module, ECA is applied to the transparent conductive oxide layer, which is the top layer of the perovskite solar cell, and wires are placed on the ECA and then cured by heat treatment. At this time, various thin films of the perovskite solar cell layer undergo physical degradation due to differences in the coefficients of thermal expansion of various materials, such as ECA and wires. This causes a decrease in module output due to delamination of the perovskite solar cell layer and exacerbates the decline in module reliability.

[0005] An embodiment of the present invention can reduce or prevent delamination of the solar cell layer by providing a buffering effect and electrical connection between the solar cell and the conductive member.

[0006] An embodiment of the present invention for achieving the above-described purpose discloses a method for forming an electrode of a solar cell module, comprising the steps of forming an electrode on a solar cell and disposing of a conductive member on the electrode, wherein the conductive member is applied to the electrode having a width smaller than that of the electrode with respect to one direction.

[0007] Another embodiment of the present invention for achieving the above-described purpose discloses a solar cell module comprising a plurality of solar cell cells arranged in series or parallel, a first electrode disposed on the solar cell, and a conductive member disposed on the first electrode, wherein the conductive member is applied to the electrode having a width smaller than that of the electrode with respect to one direction.

[0008] A solar cell module according to an embodiment of the present invention provides a buffering effect and electrical connection between a solar cell and a conductive member, and can prevent delamination of the solar cell layers due to the difference in the coefficient of thermal expansion of the materials between the layers.

[0009] FIG. 1 is a schematic plan view illustrating an example of a solar cell module according to one embodiment of the present invention.

[0010] Figure 2 is a cross-sectional view taken along the line X-X' of Figure 1.

[0011] Figure 3 is a plan view schematically illustrating another example of Figure 1.

[0012] FIG. 4 is a cross-sectional view schematically illustrating an example of a solar cell module according to another embodiment of the present invention.

[0013] FIG. 5 is a flowchart illustrating an example of an electrode formation method according to an embodiment of the present invention.

[0014] FIG. 6 is a cross-sectional view schematically illustrating an example of a solar cell module manufactured by the electrode formation method of FIG. 5.

[0015] FIG. 7 is a flowchart illustrating an example of an electrode formation method according to another embodiment of the present invention.

[0016] FIGS. 8a to 8c are cross-sectional views schematically illustrating an example of the electrode formation method of FIG. 7.

[0017] An embodiment of the present invention for achieving the above-described purpose discloses a method for forming an electrode of a solar cell module, comprising the steps of forming an electrode on a solar cell and disposing of a conductive member on the electrode, wherein the conductive member is applied to the electrode having a width smaller than that of the electrode with respect to one direction.

[0018] The above solar cell includes a front electrode, and the front electrode can be in contact with the first electrode.

[0019] The above solar cells can be arranged in series or in parallel in multiple numbers.

[0020] After the step of placing the conductive member, the method may further include the step of placing a wire on the conductive member and the step of heat-treating the conductive member and the wire.

[0021] The above wire may include a core-shell structure.

[0022] The core of the above wire comprises a conductive metal, and the shell of the above wire may comprise a solder alloy.

[0023] The shell of the above wire can be melted and soldered at 100°C to 140°C.

[0024] The above shell may include one or more selected from SnPb, SnPbAg, SnPbBi, SnAg, SnAgBi, SnAgCu, SnBi, and SnCu.

[0025] The above conductive member may further include a metal filler.

[0026] The above conductive member may include an ECA (Electrically Conductive Adhesive).

[0027] Another embodiment of the present invention for achieving the above-described purpose discloses a solar cell module comprising a plurality of solar cell cells arranged in series or parallel, a first electrode disposed on the solar cell, and a conductive member disposed on the first electrode, wherein the conductive member is applied to the electrode having a width smaller than that of the electrode with respect to one direction.

[0028] The above solar cell includes a front electrode, and the front electrode can be in contact with the first electrode.

[0029] A wire may be further disposed on the above conductive member.

[0030] The above wire may include a core-shell structure.

[0031] The core of the above wire comprises a conductive metal, and the shell of the above wire may comprise a solder alloy.

[0032] The shell of the above wire can be melted and soldered at 100°C to 140°C.

[0033] The above shell may include one or more selected from SnPb, SnPbAg, SnPbBi, SnAg, SnAgBi, SnAgCu, SnBi, and SnCu.

[0034] The above conductive member may further include a metal filler.

[0035] The above conductive member may include an ECA (Electrically Conductive Adhesive).

[0036] The first electrode may be arranged linearly or in a point shape on one region of the plurality of solar cells arranged in series or parallel.

[0037] The present invention is capable of various modifications and may have various embodiments; specific embodiments are illustrated in the drawings and described in detail in the detailed description. The effects and features of the present invention, and the methods for achieving them, will become clear by referring to the embodiments described below in detail together with the drawings. However, the present invention is not limited to the embodiments disclosed below but can be implemented in various forms.

[0038] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. When describing with reference to the drawings, identical or corresponding components are given the same reference numerals, and redundant descriptions thereof will be omitted.

[0039] In the following embodiments, terms such as first, second, etc. are used not in a limiting sense, but for the purpose of distinguishing one component from another component.

[0040] In the following examples, singular expressions include plural expressions unless the context clearly indicates otherwise.

[0041] In the following embodiments, terms such as "include" or "have" mean that the features or components described in the specification are present, and do not preclude the possibility that one or more other features or components may be added.

[0042] In the drawings, the size of components may be exaggerated or reduced for convenience of explanation. For example, the size and thickness of each component shown in the drawings are depicted arbitrarily for convenience of explanation, so the present invention is not necessarily limited to what is illustrated.

[0043] Where an embodiment can be implemented differently, a specific process sequence may be performed differently from the order described. For example, two processes described consecutively may be performed substantially simultaneously or proceed in the reverse order of the description.

[0044] An embodiment of the present invention for achieving the above-described purpose relates to a method for forming an electrode of a solar cell module, comprising the steps of forming an electrode on a solar cell and disposing of a conductive member on the electrode, wherein the conductive member is applied to the electrode having a width smaller than that of the electrode with respect to one direction, and to a solar cell module to which the same is applied. This is explained with reference to FIGS. 1 to 7 and FIGS. 8a to 8c.

[0045] FIG. 1 is a schematic plan view illustrating an example of a solar cell module according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along the line X-X' of FIG. 1.

[0046] Referring to FIGS. 1 and 2, a solar cell module may include a plurality of solar cell cells (100) arranged in series or parallel, a first electrode (110) arranged on the solar cell (100), a second electrode (111) arranged intersecting the first electrode (110), and a conductive member (120) arranged on the first electrode (110).

[0047] The solar cell (100) may include a perovskite solar cell, a silicon solar cell, or a perovskite / silicon tandem solar cell.

[0048] For example, a solar cell (100) may include a rear electrode, a front electrode, and a photoactive layer disposed between the rear electrode and the front electrode, and as an optional embodiment, may include a hole transport layer disposed between the rear electrode and the photoactive layer and an electron transport layer disposed between the front electrode and the photoactive layer. In this case, the arrangement of the hole transport layer and the electron transport layer may be interchanged, and if the electron transport layer is disposed between the rear electrode and the photoactive layer, the hole transport layer may be disposed between the front electrode and the photoactive layer.

[0049] The back electrode can be formed of a conductive material that is transparent.

[0050] For example, the back electrode may include a transparent conductive oxide, a carbonaceous conductive material, and a metallic material. Examples of transparent conductive oxides may include ITO (Indium Tin Oxide), ICO (Indium Cerium Oxide), IWO (Indium Tungsten Oxide), ZITO (Zinc Indium Tin Oxide), ZIO (Zinc Indium Oxide), ZTO (Zinc Tin Oxide), GITO (Gallium Indium Tin Oxide), GIO (Gallium Indium Oxide), GZO (Gallium Zinc Oxide), AZO (Aluminum-doped Zinc Oxide), FTO (Fluorine Tin Oxide), ZnO, etc. Carbonaceous conductive materials may include, for example, graphene or carbon nanotubes, and metallic materials may include, for example, metal nanowires or multilayer metal thin films such as Au / Ag / Cu / Mg / Mo / Ti. In this specification, the term "transparent" refers to the ability to transmit light to a certain degree or more, and is not necessarily interpreted to mean complete transparency. The materials described above are not necessarily limited to the embodiments described above and can be formed from various materials, and their structures can also be varied, such as being single-layer or multilayer.

[0051] The hole transport layer may be a layer formed on the back electrode through which holes formed in the light absorption layer are transported. For example, the hole transport layer may include one or more selected from tungsten oxide (WOx), molybdenum oxide (MoOx), vanadium oxide (V2O5), and nickel oxide (NiOx), and may also include at least one selected from the group consisting of monomolecular hole transport materials and polymeric hole transport materials, but is not limited thereto and any material used in the industry may be used. For example, spiro-MeOTAD [2,2',7,7'-tetrakis(N,Np-dimethoxy-phenylamino)-9,9'-spirobifluorene] may be used as the above-mentioned single-molecule hole transport material, and P3HT [poly(3-hexylthiophene)], PTAA (polytriarylamine), poly(3,4-ethylenedioxythiophene) or polystyrene sulfonate (PEDOT:PSS) may be used as the above-mentioned polymer hole transport material, but are not limited thereto.

[0052] Meanwhile, the hole transport layer may further include a doping material. For example, the doping material may be a dopant selected from the group consisting of Li-based dopants, Co-based dopants, Cu-based dopants, Cs-based dopants, and combinations thereof, but is not limited thereto.

[0053] The light absorption layer can be formed on the hole transport layer and, for example, may include perovskite or silicon, and can perform the role of separating hole-electron pairs generated by receiving light energy from the sun into electrons or holes. At this time, electrons formed in the light absorption layer are transferred to the electron transport layer described later, and holes formed in the light absorption layer can be transferred to the hole transport layer.

[0054] The electron transport layer may be formed on the light absorption layer and, for example, may include one or more selected from SnOx, TiOx, ZnOx, WOx, NbOx, InOx, AlOx, HfOx, BaSnOx, ZrOx, VOx, and CeOx.

[0055] The front electrode can be formed of a conductive material that is transparent.

[0056] For example, the front electrode may include a transparent conductive oxide, a carbonaceous conductive material, and a metallic material. Examples of transparent conductive oxides that may be used include ITO (Indium Tin Oxide), ICO (Indium Cerium Oxide), IWO (Indium Tungsten Oxide), ZITO (Zinc Indium Tin Oxide), ZIO (Zinc Indium Oxide), ZTO (Zinc Tin Oxide), GITO (Gallium Indium Tin Oxide), GIO (Gallium Indium Oxide), GZO (Gallium Zinc Oxide), AZO (Aluminum-doped Zinc Oxide), FTO (Fluorine Tin Oxide), ZnO, etc. Carbonaceous conductive materials may include, for example, graphene or carbon nanotubes, and metallic materials may include, for example, metal nanowires or multilayer metal thin films such as Au / Ag / Cu / Mg / Mo / Ti. In this specification, the term "transparent" refers to the ability to transmit light to a certain degree or more, and is not necessarily interpreted to mean complete transparency. The materials described above are not necessarily limited to the embodiments described above and can be formed from various materials, and their structures can also be varied, such as being single-layer or multilayer.

[0057] Meanwhile, the solar cell (100) may include a tandem solar cell in which a silicon solar cell including a silicon light-absorbing layer and a perovskite solar cell including a perovskite light-absorbing layer are tandem-bonded to each other.

[0058] A tandem solar cell may include a silicon semiconductor layer, a back electrode disposed on the silicon semiconductor layer, a hole transport layer disposed on the back electrode, a perovskite light absorption layer disposed on the hole transport layer, an electron transport layer formed on the perovskite light absorption layer, and a front electrode.

[0059] At this time, the back electrode, hole transport layer, electron transport layer, and front electrode are identical to those described above, so a detailed explanation will be omitted.

[0060] The first electrode (110) may be placed on the front electrode of the solar cell (100) and may include, for example, one or more selected from gold (Au), silver (Ag), copper (Cu) and titanium (Ti).

[0061] The first electrode (110) is positioned between the conductive member (120) described later and the front electrode of the solar cell (100) to provide a buffering effect between the conductive member (120) and the front electrode of the solar cell (100) and simultaneously enable a smooth electrical connection.

[0062] The conductive member (120) may be placed on the first electrode (110) and may include, for example, a conductive adhesive material, and as a specific example, may include an ECA (Electrically Conductive Adhesive).

[0063] Meanwhile, since the conductive member (120) and the front electrode of the solar cell (100) have different coefficients of thermal expansion, if the conductive member (120) is directly applied to the front electrode of the solar cell (100) to perform the tabbing process, the solar cell (100) may peel off due to the difference in coefficients of thermal expansion between the conductive member (120) and the front electrode of the solar cell (100). Therefore, by placing the first electrode (110) between the conductive member (120) and the front electrode of the solar cell (100), a buffering effect can be provided, and at the same time, a smooth electrical connection can be provided.

[0064] Referring again to FIG. 1, a solar cell module may have a first electrode (110) arranged linearly on a plurality of solar cell cells (100), and a conductive member (120) may be applied along the first electrode (110). At this time, when the length of the solar cell module is X, the area (X*(A)) of the conductive member (120) may be smaller than the area (X*(A+a)) of the first electrode (110). By forming the area (X*(A+a)) of the first electrode (110) to be larger than the area (X*(A)) of the conductive member (120), the conductive member (120) may not come into contact with the solar cell (100), thereby preventing delamination caused by the difference in thermal expansion coefficients between them.

[0065] However, as in the embodiment of the present invention, if a first electrode (110) is additionally placed between the conductive member (120) and the front electrode of the solar cell (100), and the area (X*(a)) of the first electrode (110) is increased to be wider than when only the existing conductive member (120) is placed, the light absorbed by the solar cell (100) is blocked, and the shading loss may increase to the level of a, which is the process tolerance. However, the solar cell module according to one embodiment of the present invention can prevent delamination caused by the difference in the coefficient of thermal expansion, thereby improving the reliability of the solar cell module.

[0066] Figure 3 is a plan view schematically illustrating another example of Figure 1.

[0067] Referring to FIG. 3, the solar cell module may include a solar cell (200), a first electrode (210) disposed in a region on the solar cell (200), a second electrode (211) disposed intersecting the first electrode (210), and a conductive member (220) disposed on the first electrode (210), and may further include a second electrode (211) intersecting the first electrode (210).

[0068] At this time, the first electrode (210) may be arranged in multiple units spaced apart from each other to cover only a portion of the solar cell (200), for example, in the form of an island pattern, or in a dot shape as another expression.

[0069] The conductive member (220) can be applied to the first electrode (210) with a width (A) smaller than the width (A+a) of the first electrode (210).

[0070] When the first electrode (210) is arranged in a dot shape like this, the area covering the solar cell (200) can be reduced compared to the solar cell module in which the first electrode (110) is arranged in a linear shape as in FIG. 1 of the aforementioned embodiment, thereby reducing the shading loss.

[0071] As a result, in a solar cell module according to one embodiment of the present invention, a first electrode (110, 210) is disposed between a conductive member (120, 220) and a solar cell (100, 200), thereby preventing delamination caused by the difference in the coefficient of thermal expansion between the conductive member (120) and the front electrode of the solar cell (100), thereby improving the reliability of the solar cell module and simultaneously providing a smooth electrical connection between the conductive member (120) and the solar cell (100).

[0072] FIG. 4 is a cross-sectional view schematically illustrating an example of a solar cell module according to another embodiment of the present invention.

[0073] Referring to FIG. 4, the solar cell module may include a solar cell (300), a first electrode (310) disposed on the solar cell (300), a conductive member (320) disposed on the first electrode (310), and a wire (330) disposed on the conductive member (320).

[0074] The solar cell (300) may include a perovskite solar cell, a silicon solar cell, or a perovskite / silicon tandem solar cell.

[0075] For example, a solar cell (300) may include a rear electrode, a front electrode, and a photoactive layer disposed between the rear electrode and the front electrode, and as an optional embodiment, may include a hole transport layer disposed between the rear electrode and the photoactive layer and an electron transport layer disposed between the front electrode and the photoactive layer. In this case, the arrangement of the hole transport layer and the electron transport layer may be interchanged, and if the electron transport layer is disposed between the rear electrode and the photoactive layer, the hole transport layer may be disposed between the front electrode and the photoactive layer.

[0076] The back electrode can be formed of a conductive material that is transparent.

[0077] For example, the back electrode may include a transparent conductive oxide, a carbonaceous conductive material, and a metallic material. Examples of transparent conductive oxides may include ITO (Indium Tin Oxide), ICO (Indium Cerium Oxide), IWO (Indium Tungsten Oxide), ZITO (Zinc Indium Tin Oxide), ZIO (Zinc Indium Oxide), ZTO (Zinc Tin Oxide), GITO (Gallium Indium Tin Oxide), GIO (Gallium Indium Oxide), GZO (Gallium Zinc Oxide), AZO (Aluminum-doped Zinc Oxide), FTO (Fluorine Tin Oxide), ZnO, etc. Carbonaceous conductive materials may include, for example, graphene or carbon nanotubes, and metallic materials may include, for example, metal nanowires or multilayer metal thin films such as Au / Ag / Cu / Mg / Mo / Ti. In this specification, the term "transparent" refers to the ability to transmit light to a certain degree or more, and is not necessarily interpreted to mean complete transparency. The materials described above are not necessarily limited to the embodiments described above and can be formed from various materials, and their structures can also be varied, such as being single-layer or multilayer.

[0078] The hole transport layer may be a layer formed on the back electrode through which holes formed in the light absorption layer are transported. For example, the hole transport layer may include one or more selected from tungsten oxide (WOx), molybdenum oxide (MoOx), vanadium oxide (V2O5), and nickel oxide (NiOx), and may also include at least one selected from the group consisting of monomolecular hole transport materials and polymeric hole transport materials, but is not limited thereto and any material used in the industry may be used. For example, spiro-MeOTAD [2,2',7,7'-tetrakis(N,Np-dimethoxy-phenylamino)-9,9'-spirobifluorene] may be used as the above-mentioned single-molecule hole transport material, and P3HT [poly(3-hexylthiophene)], PTAA (polytriarylamine), poly(3,4-ethylenedioxythiophene) or polystyrene sulfonate (PEDOT:PSS) may be used as the above-mentioned polymer hole transport material, but are not limited thereto.

[0079] Meanwhile, the hole transport layer may further include a doping material. For example, the doping material may be a dopant selected from the group consisting of Li-based dopants, Co-based dopants, Cu-based dopants, Cs-based dopants, and combinations thereof, but is not limited thereto.

[0080] The light absorption layer can be formed on the hole transport layer and, for example, may include perovskite or silicon, and can perform the role of separating hole-electron pairs generated by receiving light energy from the sun into electrons or holes. At this time, electrons formed in the light absorption layer are transferred to the electron transport layer described later, and holes formed in the light absorption layer can be transferred to the hole transport layer.

[0081] The electron transport layer may be formed on the light absorption layer and, for example, may include one or more selected from SnOx, TiOx, ZnOx, WOx, NbOx, InOx, AlOx, HfOx, BaSnOx, ZrOx, VOx, and CeOx.

[0082] The front electrode can be formed of a conductive material that is transparent.

[0083] For example, the front electrode may include a transparent conductive oxide, a carbonaceous conductive material, and a metallic material. Examples of transparent conductive oxides that may be used include ITO (Indium Tin Oxide), ICO (Indium Cerium Oxide), IWO (Indium Tungsten Oxide), ZITO (Zinc Indium Tin Oxide), ZIO (Zinc Indium Oxide), ZTO (Zinc Tin Oxide), GITO (Gallium Indium Tin Oxide), GIO (Gallium Indium Oxide), GZO (Gallium Zinc Oxide), AZO (Aluminum-doped Zinc Oxide), FTO (Fluorine Tin Oxide), ZnO, etc. Carbonaceous conductive materials may include, for example, graphene or carbon nanotubes, and metallic materials may include, for example, metal nanowires or multilayer metal thin films such as Au / Ag / Cu / Mg / Mo / Ti. In this specification, the term "transparent" refers to the ability to transmit light to a certain degree or more, and is not necessarily interpreted to mean complete transparency. The materials described above are not necessarily limited to the embodiments described above and can be formed from various materials, and their structures can also be varied, such as being single-layer or multilayer.

[0084] Meanwhile, the solar cell (300) may include a tandem solar cell in which a silicon solar cell including a silicon light-absorbing layer and a perovskite solar cell including a perovskite light-absorbing layer are tandem-bonded to each other.

[0085] A tandem solar cell may include a silicon semiconductor layer, a back electrode disposed on the silicon semiconductor layer, a hole transport layer disposed on the back electrode, a perovskite light absorption layer disposed on the hole transport layer, an electron transport layer formed on the perovskite light absorption layer, and a front electrode.

[0086] At this time, the back electrode, hole transport layer, electron transport layer, and front electrode are identical to those described above, so a detailed explanation will be omitted.

[0087] The first electrode (310) may be placed on the front electrode of the solar cell (300) and may include, for example, one or more selected from gold (Au), silver (Ag), copper (Cu) and titanium (Ti).

[0088] The first electrode (310) is positioned between the conductive member (320) described later and the front electrode of the solar cell (300), thereby acting as a buffer between the conductive member (320) and the front electrode of the solar cell (300) and simultaneously enabling a smooth electrical connection.

[0089] The conductive member (320) may be placed on the first electrode (310) and may include, for example, an ECA (Electrically Conductive Adhesive).

[0090] Meanwhile, since the conductive member (320) and the front electrode of the solar cell (300) have different coefficients of thermal expansion, if the conductive member (320) is directly applied to the front electrode of the solar cell (300) to perform the tabbing process, the solar cell (300) may peel off due to the difference in coefficients of thermal expansion between the conductive member (320) and the front electrode of the solar cell (300). Therefore, by placing the first electrode (310) between the conductive member (320) and the front electrode of the solar cell (300), a buffering effect can be provided, and at the same time, a smooth electrical connection can be provided.

[0091] Meanwhile, "although not illustrated, the structure of FIG. 1 or FIG. 2 may be applied as is in the case of this embodiment." In a solar cell module, a first electrode (310) is arranged linearly on a plurality of solar cell cells (300), and a conductive member (320) may be applied along the first electrode (310) on the first electrode (310). At this time, when the length of the solar cell module is X, the area (X*(A)) of the conductive member (320) may be smaller than the area (X*(A+a)) of the first electrode (310). By forming the area (X*(A+a)) of the first electrode (310) to be larger than the area (X*(A)) of the conductive member (320), the conductive member (320) is prevented from coming into contact with the solar cell (300), thereby preventing the delamination phenomenon caused by the difference in thermal expansion coefficients between them.

[0092] However, as in the embodiment of the present invention, if a first electrode (310) is additionally placed between the conductive member (320) and the front electrode of the solar cell (300), and the area (X*(a)) of the first electrode (310) is increased to be wider than when only the existing conductive member (320) is placed, the light absorbed by the solar cell (300) is blocked, and the shading loss may increase to the level of a, which is the process tolerance. However, the solar cell module according to one embodiment of the present invention can prevent delamination caused by the difference in the coefficient of thermal expansion, thereby improving the reliability of the solar cell module.

[0093] In addition, if a wire (330) is placed on the conductive member (320) and used in combination with the conductive member (320), electrical characteristics can be improved, thereby minimizing the shading loss due to the increase in the area of ​​the first electrode (310).

[0094] Meanwhile, the wire (330) may include a core (331) and a shell (332), wherein the core (331) may include a conductive metal and the shell (332) may include a solder alloy that melts at 100°C to 200°C. As a specific example, the core (331) may include one or more selected from gold (Au), silver (Ag), copper (Cu), and titanium (Ti), and the shell (332) may include one or more selected from SnPb, SnPbAg, SnPbBi, SnAg, SnAgBi, SnAgCu, SnBi, and SnCu, and as an optional example, may include SnPbBi.

[0095] When SnPbBi is included as a solder, it can be soldered through low-temperature heat treatment (140℃) during the tabbing process, thereby securing the adhesion between the conductive member (320) and the wire (330).

[0096] As a result, in a solar cell module according to one embodiment of the present invention, a first electrode (110) is disposed between a conductive member (120) and a solar cell (100), thereby preventing delamination caused by the difference in thermal expansion coefficients between the conductive member (120) and the front electrode of the solar cell (100), thereby improving the reliability of the solar cell module and simultaneously providing a smooth electrical connection between the conductive member (120) and the solar cell (100).

[0097] FIG. 5 is a flowchart illustrating an example of an electrode formation method according to an embodiment of the present invention, and FIG. 6 is a cross-sectional view schematically illustrating an example of a solar cell module manufactured by the electrode formation method of FIG. 5.

[0098] Referring to FIGS. 5 and 6, the electrode forming method may include the step of forming an electrode on a solar cell (S10) and the step of placing a conductive member on the electrode (S11).

[0099] In the step (S10) of forming an electrode on a solar cell, an electrode (11) can be placed on the solar cell (10).

[0100] At this time, the solar cell (10) may include one of a perovskite solar cell, a silicon solar cell, or a perovskite / silicon tandem solar cell, with a transparent electrode disposed on the top surface, and a plurality of such cells may be arranged in series or in parallel. Along the solar cells (10) arranged in series or in parallel, electrodes (11) may be arranged linearly or in a dot shape to cover a region of the solar cell (10). At this time, the electrodes may include a conductive metal.

[0101] In the step (S11) of placing a conductive member on an electrode, the conductive member (12) may be placed on an electrode (11) that is arranged in a linear or dot shape, and the conductive member (12) may be placed on the electrode (11) with a width or area narrower than that of the electrode (11).

[0102] FIG. 7 is a flowchart illustrating an example of an electrode formation method according to another embodiment of the present invention.

[0103] Referring to FIG. 7, the electrode forming method may include the steps of forming an electrode on a solar cell (S20), placing a conductive member on the electrode (S21), placing a wire on the conductive member (S22), and heat-treating the conductive member and the wire (S23).

[0104] FIGS. 8a to 8c are cross-sectional views schematically illustrating an example of the electrode formation method of FIG. 7.

[0105] Referring to FIG. 8a, in the step (S20) of forming an electrode on a solar cell, the electrode (21) can be placed on the solar cell (20).

[0106] At this time, the solar cell (20) may include one of a perovskite solar cell, a silicon solar cell, or a perovskite / silicon tandem solar cell, with a transparent electrode disposed on the top, and a plurality of such cells may be arranged in series or in parallel. Along the solar cells (20) arranged in series or in parallel, electrodes (21) may be arranged linearly or in a dot shape on the solar cells (20) to cover a region of the solar cells (20). At this time, the electrodes may include a conductive metal.

[0107] In the step (S21) of placing a conductive member on an electrode, the conductive member (22) may be placed on an electrode (21) arranged in a linear or dot shape, and the conductive member (22) may include ECA and may be placed on the electrode (21) by being applied in a manner narrower than the width or area of ​​the electrode (21). By placing the conductive member (22) on the electrode (21) by being applied in a manner narrower than the width or area of ​​the electrode (21), contact between the conductive member (22) and the solar cell (20) can be prevented.

[0108] Meanwhile, due to the difference in thermal expansion coefficients between the conductive member (22) and the transparent electrode of the solar cell (20), a peeling phenomenon may occur. Therefore, if the conductive member (22) is applied directly onto the transparent electrode of the solar cell (20), product defects may occur due to this peeling phenomenon and reliability may decrease.

[0109] Referring to 8b, in the step (S22) of placing a wire on a conductive member, the wire (23) may be placed on the conductive member (22). At this time, the wire (23) may have a structure including a core (23-1) and a shell (23-2), the core (23-1) may include a conductive metal, and the shell (23-2) may include a solder alloy.

[0110] Referring to 8c, in the step (S23) of heat treating the conductive member and the wire, the wire (23) placed on the conductive member (22) is heat treated at a temperature of 100°C to 200°C so that the shell (23-2) of the conductive member (22) and the wire (23) can melt and solder each other. At this time, the shell (23-2) may include one or more selected from SnPb, SnPbAg, SnPbBi, SnAg, SnAgBi, SnAgCu, SnBi, and SnCu, and may include SnPbBi as an optional example.

[0111] When SnPbBi is included as a solder, it can be soldered by heat treatment at 100°C to 140°C.

[0112] Meanwhile, the conductive member (22) may include a metal filler (121) to electrically connect the core (23-1) of the wire (23) and the electrode (21).

[0113] Consequently, in a solar cell module to which the electrode forming method according to an embodiment of the present invention is applied, an electrode is disposed between a conductive member and a solar cell, thereby preventing delamination caused by the difference in thermal expansion coefficients between the conductive member and the solar cell, which can improve the reliability of the solar cell module and provide a smooth electrical connection between the conductive member and the solar cell.

[0114] As such, the present invention has been described with reference to the embodiments illustrated in the drawings, but this is merely illustrative, and those skilled in the art will understand that various modifications and equivalent alternative embodiments are possible therefrom. Accordingly, the true technical scope of protection of the present invention should be determined by the technical spirit of the appended claims.

[0115] The specific implementations described in the embodiments are examples and do not limit the scope of the embodiments in any way. For the sake of brevity of the specification, descriptions of conventional electronic configurations, control provision methods, software, and other functional aspects of said provision methods may be omitted. Additionally, the connections of lines or connecting members between components shown in the drawings are illustrative of functional connections and / or physical or circuit connections, and may be replaced or additionally represented as various functional connections, physical connections, or circuit connections in actual devices. Furthermore, unless specifically stated as "essential," "importantly," etc., a component may not be absolutely necessary for the application of the present invention.

[0116] In the specification of the embodiments (particularly in the claims), the use of the term "the above" and similar descriptive terms may be in both singular and plural. Furthermore, where a range is described in the embodiments, it is considered to include the invention with respect to individual values ​​within said range (unless otherwise stated), and is equivalent to describing each individual value constituting said range in the detailed description. Finally, regarding the steps constituting the method according to the embodiments, unless explicitly stated in order or otherwise stated, said steps may be performed in a suitable order. The embodiments are not necessarily limited by the order in which said steps are described. The use of any examples or exemplary terms (e.g., etc.) in the embodiments is merely for the purpose of describing the embodiments in detail, and the scope of the embodiments is not limited by said examples or exemplary terms unless limited by the claims. Furthermore, those skilled in the art will understand that various modifications, combinations, and changes may be made according to design conditions and factors within the scope of the claims or equivalents.

[0117] [Explanation of the symbol]

[0118] 100, 200, 300: Solar cell

[0119] 110, 210, 310: First electrode

[0120] 120, 220, 320: Conductive member

[0121] 330: Wire

[0122] 331: Core

[0123] 332: Shell

Claims

1. A method for forming electrodes of a solar cell module, A step of forming an electrode on a solar cell; and The method includes the step of placing a conductive member on the electrode, and A method for forming an electrode, wherein the conductive member is applied on the electrode to have a width smaller than that of the electrode with respect to one direction.

2. In Paragraph 1, The above solar cell includes a front electrode. The above front electrode is in contact with the above electrode, an electrode forming method.

3. In Paragraph 1, A method for forming electrodes in which a plurality of solar cells are arranged in series or parallel.

4. In Paragraph 1, A method for forming an electrode, further comprising: a step of placing a wire on the conductive member after the step of placing the conductive member; and a step of heat-treating the conductive member and the wire.

5. In Paragraph 4, The above wire is a method for forming an electrode, comprising a core-shell structure.

6. In Paragraph 5, The core of the above wire comprises a conductive metal, and A method for forming an electrode, wherein the shell of the above-mentioned wire comprises a solder alloy.

7. In Paragraph 6, A method for forming an electrode, wherein the shell of the above wire is melted and soldered at 100°C to 140°C.

8. In Paragraph 5, A method for forming an electrode, wherein the shell comprises one or more selected from SnPb, SnPbAg, SnPbBi, SnAg, SnAgBi, SnAgCu, SnBi, and SnCu.

9. In Paragraph 1, The above conductive member is a method for forming an electrode, further comprising a metal filler.

10. In Paragraph 1, The above conductive member is an electrode forming method comprising an ECA (Electrically Conductive Adhesive).

11. Multiple solar cells arranged in series or parallel; A first electrode disposed on the above solar cell; and It includes a conductive member disposed on the first electrode, and A solar cell module in which the conductive member is applied on the electrode with a width smaller than that of the electrode in one direction.

12. In Paragraph 11, The above solar cell includes a front electrode. The above-mentioned front electrode is a solar cell module in contact with the above-mentioned first electrode.

13. In Paragraph 11, A solar cell module having a wire further disposed on the above conductive member.

14. In Paragraph 13, The above wire is a solar cell module including a core-shell structure.

15. In Paragraph 14, The core of the above wire comprises a conductive metal, and A solar cell module in which the shell of the above wire comprises a solder alloy.

16. In Paragraph 15, A solar cell module in which the shell of the above wire is melted and soldered at 100°C to 140°C.

17. In Paragraph 14, The above shell comprises one or more selected from SnPb, SnPbAg, SnPbBi, SnAg, SnAgBi, SnAgCu, SnBi, and SnCu, forming a solar cell module.

18. In Paragraph 11, The above conductive member is a solar cell module further comprising a metal filler.

19. In Paragraph 11, The above conductive member is a solar cell module comprising an ECA (Electrically Conductive Adhesive).

20. In Paragraph 11, The above first electrode is a solar cell module arranged linearly or in a point shape on one region of the plurality of solar cell cells arranged in series or parallel.

Images