Solar cells and substrates for solar cells

Abstract

To improve the quality of a completed solar battery by implementing the removal of particles and cracks on a cell.SOLUTION: A solar battery includes a substrate having an electrical conductive polarity, and a first thin film layer formed on the substrate, and a substrate separation portion that separates the substrate into a plurality of unit cells is formed on one surface of the substrate, and is formed to gradually decrease in size in a downward direction, and the first thin film layer includes a first separation member inserted into the substrate separation portion.SELECTED DRAWING: Figure 3E

Description

Technical Field

[0001] The present invention relates to a solar cell, and more particularly to a solar cell that combines a substrate-type solar cell and a thin-film solar cell.

Background Art

[0002] A solar cell is a device that converts light energy into electrical energy by utilizing the properties of semiconductors.

[0003] A solar cell has a PN junction structure formed by joining a P (positive) type semiconductor and an N (negative) type semiconductor. When sunlight is incident on a solar cell having such a structure, holes and electrons are generated in the semiconductor by the energy of the incident sunlight. At this time, due to the electric field generated at the PN junction, the holes (+) move toward the P-type semiconductor, and the electrons (-) move toward the N-type semiconductor, generating a potential difference and thus enabling the production of electric power.

[0004] Such solar cells can generally be classified into substrate-type solar cells and thin-film solar cells.

[0005] The substrate-type solar cell is manufactured by using a semiconductor material itself, such as a silicon wafer, as a substrate, and the thin-film solar cell is manufactured by forming a semiconductor in the form of a thin film on a substrate such as glass.

[0006] The substrate-type solar cell has the advantage of being more efficient than the thin-film solar cell, and the thin-film solar cell has the advantage of having a lower manufacturing cost than the substrate-type solar cell.

[0007] Therefore, a solar cell that combines the substrate-type solar cell and the thin-film solar cell has been proposed. Hereinafter, the conventional solar cell will be described with reference to the drawings.

[0008] Figures 1A to 1C are schematic side views illustrating a conventional method for manufacturing solar cells.

[0009] First, a substrate 100 is prepared as shown in Figure 1A. Here, the substrate 100 may be either a silicon wafer or glass, selected from among these.

[0010] Next, as shown in Figure 1B, the cell manufacturing process is carried out by forming a plurality of thin film layers 200 on the substrate 100. Each of the plurality of thin film layers 200 may be a semiconductor layer or a conductive layer selected from among these.

[0011] Next, as shown in Figure 1C, a separation section 300 is formed to separate the cell on which multiple thin film layers 200 are formed into unit cells. The separation section 300 can be formed by a laser scribing process. The scribing process can be performed by a scribing device 300a that irradiates the cell with a laser beam.

[0012] In this case, the conventional method for manufacturing a solar cell is implemented by forming multiple thin film layers on the substrate 100, and then performing the scribing step. As a result, the conventional method for manufacturing a solar cell has the following problems.

[0013] Firstly, in conventional solar cell manufacturing methods, the scribing process is implemented so that bonding occurs between the multiple thin film layers 200 in the area irradiated by the laser. As a result, conventional solar cell manufacturing methods have the problem of reducing the amount of electricity that the solar cell can produce due to the occurrence of a layer short phenomenon, which hinders the movement of holes (+) and electrons (-) between the multiple thin film layers 200.

[0014] Secondly, conventional solar cell manufacturing methods involve the formation of particles 400 and cracks 500 on the cell by performing the scribing process. As a result, conventional solar cell manufacturing methods have the problem that the quality of the completed solar cell is reduced due to the particles 400 and cracks 500. [Overview of the Initiative] [Problems that the invention aims to solve]

[0015] This invention was devised to solve the above-mentioned problems and relates to a solar cell and a method for manufacturing a solar cell that can reduce the possibility of layer shorting occurring.

[0016] The present invention relates to a solar cell and a method for manufacturing a solar cell that can reduce the degree to which the quality of the completed solar cell deteriorates due to particles and cracks formed on the substrate. [Means for solving the problem]

[0017] To solve the problems described above, the present invention may include the following configuration.

[0018] The solar cell according to the present invention includes a substrate having an electric conduction polarity and a first thin film layer formed on the substrate. On one surface of the substrate, a substrate separation portion for separating the substrate into a plurality of unit cells is formed, and the substrate separation portion is formed such that its size gradually decreases as it goes in the downward direction. The first thin film layer includes a first separation member inserted into the substrate separation portion. Each of the plurality of unit cells includes a cell upper surface arranged to face upward, a cell lower surface arranged to face downward, a cell cutting groove formed on the cell upper surface, a first cutting surface arranged to face the cell cutting groove, a second cutting surface connected to each of the first cutting surface and the cell upper surface, and a third cutting surface connected to each of the first cutting surface and the cell lower surface. A first corner is formed at a portion where the first cutting surface and the second cutting surface are connected, a second corner is formed at a portion where the second cutting surface and the cell upper surface are connected, a third corner is formed at a portion where the first cutting surface and the third cutting surface are connected, and a fourth corner is formed at a portion where the third cutting surface and the cell lower surface are connected The substrate includes a substrate body having electrical conductivity polarity, a first groove formed extending from one side of the substrate body to the other side, a second groove communicating with the first groove so as to expand the etching surface facing the first groove, and a damage prevention portion formed with respect to the etching surface such that a step is created and with the second groove facing inward, wherein the second groove is not provided on the one side and the other side of the substrate body, and the damage prevention portion is provided on the one side and the other side of the substrate body. can be.

[0019] The solar cell according to the present invention may have an angle between the first and second cross-sections that is less than 180 degrees.

[0021] In the solar cell according to the present invention, the second groove can be formed to be larger in size than the damage prevention portion with respect to the scribe direction in which the first groove is formed.

[0022] In the solar cell according to the present invention, the damage prevention portion can be formed with a second thickness that is equal to or less than or equal to the first thickness of the substrate body, and has a value of 1 / 2 or more of the first thickness.

[0023] The solar cell according to the present invention has a damage prevention portion formed such that a step is created with respect to the etched surface, and includes a first prevention member, a second prevention member formed at a position spaced apart from the first prevention member, and connecting members connected to the first prevention member and the second prevention member, wherein the connecting members can be connected such that a step is created between the first prevention member and the second prevention member.

Advantages of the Invention

[0026] According to the present invention, the following effects can be achieved.

[0027] The present invention can increase the power production amount by embodying to reduce the possibility of layer short-circuit phenomenon. [[ID=了30]]

[0028] The present invention can improve the quality of the completed solar cell by embodying to remove particles and cracks on the cell.

Brief Description of the Drawings

[0029] [Figure 1A] Schematic process cross-sectional view showing a method for manufacturing a solar cell according to the prior art. [Figure 1B] Schematic process cross-sectional view showing a method for manufacturing a solar cell according to the prior art. [Figure 1C] Schematic process cross-sectional view showing a method for manufacturing a solar cell according to the prior art. [Figure 2] Schematic flowchart of a method for manufacturing a solar cell according to the present invention. [Figure 3A] In the method for manufacturing a solar cell according to the present invention, a schematic process cross-sectional view showing a substrate support step. [Figure 3B] In the method for manufacturing a solar cell according to the present invention, a schematic process cross-sectional view showing a first substrate etching step. [Figure 3C] In the method for manufacturing a solar cell according to the present invention, a schematic process cross-sectional view showing that particles and cracks are formed on the cell due to the performance of the first substrate etching step. [Figure 3D] In the method for manufacturing a solar cell according to the present invention, a schematic process cross-sectional view showing a substrate on which a third substrate etching step has been performed. [Figure 3E] In the method for manufacturing a solar cell according to the present invention, a schematic process cross-sectional view showing that a first thin film layer formation step has been performed on a substrate. [Figure 3F] In the method for manufacturing a solar cell according to the present invention, a schematic process cross-sectional view showing that a second thin film layer formation step has been performed on the first thin film layer. [Figure 3G] In the method for manufacturing a solar cell according to the present invention, a schematic process cross-sectional view showing that a third thin film layer formation step has been performed on the second thin film layer. [Figure 4] Enlarged view showing an enlarged portion A of FIG. 3D. [Figure 5A] Schematic perspective view of a substrate for a solar cell according to the present invention. [Figure 5B] Schematic front view of a substrate for a solar cell according to the present invention. [Figure 5C] A side cross-sectional view shown with respect to the section line II in Figure 5B. [Figure 5D] A schematic perspective view showing a cross-section of a solar cell substrate according to the present invention. [Figure 6A] A schematic cross-sectional view of one embodiment in which a plurality of thin film layers are formed on a substrate in a solar cell according to the present invention. [Figure 6B] A schematic cross-sectional view of one embodiment in which a plurality of thin film layers are formed on a substrate in a solar cell according to the present invention. [Figure 7A] A schematic side view of the coating process in the method for manufacturing a solar cell according to the present invention. [Figure 7B] A schematic side view showing the cutting process in the method for manufacturing a solar cell according to the present invention. [Figure 7C] A schematic side view of the solar cell manufacturing method according to the present invention, showing a solar cell after the bonding process and curing process have been performed. [Figure 8] An enlarged view showing a magnified section B of Figure 7C. [Modes for carrying out the invention]

[0030] The features of each of the various embodiments of the present invention can be combined or combined with one another, either partially or whole, allowing for various technical interdependencies and drives, and each embodiment can be implemented independently of the others, or together in a related relationship. When describing a positional relationship, for example, when describing the positional relationship between two parts, such as "on top of," "above," "below," or "beside," one or more other parts may be located between the two parts, unless "immediately" or "directly" is used. When describing a temporal relationship, for example, when describing a temporal sequence, such as "after," "following," "next," or "before," non-sequential events may be included, unless "immediately" or "directly" is used.

[0031] Hereinafter, embodiments of the solar cell manufacturing method according to the present invention will be described in detail with reference to the attached figures.

[0032] The method for manufacturing a solar cell according to the present invention is for manufacturing a solar cell that converts the light energy of sunlight into electrical energy. The method for manufacturing a solar cell according to the present invention can be used to manufacture substrate-type solar cells and thin-film-type solar cells. The method for manufacturing a solar cell according to the present invention can be used to form separation sections for separating a substrate for manufacturing a solar cell into multiple parts. In the following description, the method for manufacturing a substrate-type solar cell will be described based on the method for manufacturing a solar cell according to the present invention, but it will be obvious to those skilled in the art to manufacture a thin-film-type solar cell using the method for manufacturing a solar cell according to the present invention.

[0033] Referring to Figures 2 and 3A, the method for manufacturing a solar cell according to the present invention may include a substrate support step (S100).

[0034] The substrate support step (S100) may be a step of supporting the substrate 2 in a processing space for manufacturing a solar cell. That is, the substrate support step (S100) may be a step of preparing the substrate 2 for manufacturing a solar cell. The substrate support step (S100) may be performed by a substrate loading device (not shown) that loads the substrate 2 into the processing space. The processing space may be a chamber that houses manufacturing equipment (not shown) necessary for manufacturing a solar cell. The substrate 2 is made of multiple thin film layers and may have a predetermined electrical conductivity polarity. The substrate 2 may be made of a silicon wafer. For example, the substrate 2 may be made of an N-type silicon wafer or a P-type silicon wafer. Although not shown in the figure, one surface 2a of the substrate 2 may have an uneven structure. The substrate 2 may include an upper surface of the substrate 2 that faces upward when supported in the processing space, a lower surface of the substrate 2 that faces downward, which is the opposite direction to the upward direction, and sides of the substrate connected to the upper and lower surfaces, respectively. In this case, one surface 2a of the substrate 2 can correspond to any one of the upper surface, lower surface, or sides of the substrate 2. For example, if one surface 2a of the substrate 2 corresponds to the upper surface of the substrate 2, the other surface of the substrate 2 can correspond to the lower surface of the substrate. In this case, the thin film layers formed on one surface 2a and the other surface 2b of the substrate 2 may also be formed with an uneven structure.

[0035] Referring to Figures 2 and 3B, the method for manufacturing a solar cell according to the present invention may include a first substrate etching step (S200).

[0036] The first substrate etching step (S200) may be a step of forming a first groove 2c (shown in Figure 3b) on the substrate 2. For example, the first substrate etching step (S200) may be implemented as a scribing step of irradiating the substrate 2 with a laser. When the first substrate etching step (S200) is implemented as a scribing step using a laser, the first substrate etching step (S200) may be performed by a scribing device 1a. The dashed-dotted arrow shown in Figure 3B schematically represents the laser irradiated by the scribing device 1a. In this specification, the first substrate etching step (S200) is described based on the assumption that it is performed on one surface 2a of the substrate 2, but this is illustrative, and the first substrate etching step (S200) may also be performed on another surface 2b of the substrate 2.

[0037] In the following description, the first substrate etching step (S200) will be explained based on the assumption that it was implemented in the scribing step. However, this is illustrative, and the first substrate etching step (S200) can also be performed by immersing the substrate 2 in an etching tank (not shown), or by dry etching, a mask, or the like, as long as the first groove 2c can be formed.

[0038] The first substrate etching step (S200) can be performed by irradiating the substrate 2 with a laser. The first substrate etching step (S200) can be performed by irradiating one surface 2a of the substrate 2 with a laser. This removes a predetermined area of ​​the substrate 2, thereby forming the first groove 2c. The first groove 2c formed through the first substrate etching step (S200) can be realized as a groove recessed to a predetermined depth from one surface 2a of the substrate 2. The first groove 2c can be formed in a first direction from one surface 2a of the substrate 2. The first direction can be a direction from one surface 2a of the substrate 2 toward the other surface 2b of the substrate 2. The first groove 2c can be formed extending from one side of one surface 2a of the substrate 2 to the other side of one surface 2a of the substrate 2. Figure 3b schematically shows that one first groove 2c has been formed on the substrate 2. When attempting to form a plurality of first grooves 2c on the substrate 2, the first substrate etching step (S200) can be performed by a plurality of substrate scribing devices 1a. This allows the solar cell manufacturing method according to the present invention to reduce the time required for the first substrate etching step (S200). When attempting to form a plurality of first grooves 2c on the substrate 2, the first substrate etching step (S200) can also be performed by moving a single substrate scribing device 1a.

[0039] By performing the first substrate etching step (S200), the first groove 2c may be formed to have a first depth from one surface 2a of the substrate 2. The first depth may be the size of the first groove 2c with respect to the separation direction in which one surface 2a of the substrate 2 and the other surface 2b of the substrate 2 are separated from each other. By performing the first substrate etching step (S200), the first groove 2c may be formed to have a first length. The first length may be the size of the first groove 2c with respect to the first direction. The first length and the first depth may have the same value.

[0040] The first substrate etching step (S200) can be performed before forming the first thin film layer 3 on the substrate 2. Compared to the conventional technique in which one or more thin film layers are formed on the substrate 2 and then irradiated with a laser, the solar cell manufacturing method according to the present invention can implement a preventive effect against layer shorting due to bonding between thin film layers. Therefore, the solar cell manufacturing method according to the present invention can increase the amount of electricity that the solar cell can produce.

[0041] Referring to Figures 2 and 5A to 5D, the method for manufacturing a solar cell according to the present invention may include a second substrate etching step (S300). The dots shown in Figures 5B and 5C do not represent a cross-section of the structure, but are shown to indicate the division of the structure. Also, the two rows of dashed lines shown in Figures 5A, 5C, and 5D are for omitting the length of the substrate 2 with respect to the scribing direction in which the first groove 2c is formed.

[0042] The second substrate etching step (S300) is a step of forming a second groove 2d to expand the etching surface 2e facing the first groove 2c. The second substrate etching step (S300) may be a step of forming the second groove 2d inside the first groove 2c. That is, by performing the second substrate etching step (S300), the second groove 2d can communicate with the first groove 2c. The etching surface 2e can be formed by performing the step of forming the first groove 2c. The second substrate etching step (S300) may be performed after the first groove 2c has been formed. The second substrate etching step (S300) can be performed by irradiating the substrate 2 with a laser. The second substrate etching step (S300) can be performed by etching a part of the substrate 2 facing the first groove 2c. The step of forming the first groove 2c and the second substrate etching step (S300) can be performed by a scribing device 1a that utilizes all lasers.

[0043] The solar cell manufacturing method according to the present invention allows the etching surface 2e to be expanded by the second groove 2d through the second substrate etching step (S300). Since the etching surface 2e has a better quality cross-section than the cut surface 2g of the substrate (shown in Figures 5C and 5D) formed by separating the substrate 2 into two or more parts, the solar cell manufacturing method of the present invention can improve the overall quality of the finished solar cell.

[0044] By performing the second substrate etching process (S300), the second groove 2d may be formed to have a second depth from one surface 2a of the substrate 2. The second depth may be the sum of the sizes of the first groove 2c and the second groove 2d with respect to the separation direction. The second depth may be formed to be deeper than the first depth. By performing the second substrate etching process (S300), the second groove 2d may be formed to have a second length. The second length may be the size of the second groove 2d with respect to the first direction. The second length may be formed to be shorter than the first length.

[0045] By performing the second substrate etching step (S300), a step is formed on the etched surface 2e, and a damage prevention portion 2f can be formed. The damage prevention portion 2f can be formed by forming the second groove 2d. The damage prevention portion 2f can provide support for the substrate 2 to prevent damage such as the substrate 2 separating into two or more parts. As a result, the solar cell manufacturing method according to the present invention can reduce the possibility of damage to the substrate 2 even if the substrate 2 is subjected to physical impact, such as colliding with process equipment installed in the processing space, during the process of transporting the substrate 2. Therefore, the solar cell manufacturing method according to the present invention can improve the stability of the process for manufacturing solar cells.

[0046] Referring to Figures 2 and 3C-3G, the method for manufacturing a solar cell according to the present invention may include a third substrate etching step (S400).

[0047] The third substrate etching step (S400) is a step of etching (etching) one surface 2a of the substrate 2. The third substrate etching step (S400) can be performed by etching one surface 2a of the substrate 2, including the second groove 2d, to a predetermined thickness. The third substrate etching step (S400) can be performed by an etching apparatus (not shown) for etching one surface 2a of the substrate 2. The third substrate etching step (S400) can be performed after the first substrate etching step (S200). In this specification, the third substrate etching step (S400) is described based on the assumption that it is performed on one surface 2a of the substrate 2, but this is illustrative, and the third substrate etching step (S400) can also be performed only on the other surface 2b of the substrate 2, or on one surface 2a of the substrate 2 and the other surface 2b of the substrate 2 simultaneously.

[0048] The etching apparatus performing the third substrate etching step (S400) can etch one surface 2a of the substrate 2 using a wet etching method. The wet etching method can be performed by spraying a predetermined etching solution onto the substrate 2 using a nozzle (not shown). The third substrate etching step (S400) can be performed continuously by transporting the substrate 2 with a transport roller (not shown) when spraying the predetermined etching solution onto the substrate 2 using the nozzle (not shown). The etching solution may include at least one etching substance selected from the group consisting of NaOH, KOH, HCl, HNO3, H2SO4, H3PO3, H2O2, and C2H2O4. The wet etching method can also be performed by storing the etching solution in the etching tank and immersing the substrate 2 in the etching solution.

[0049] When the third substrate etching step (S400) is performed by immersing the substrate 2 in the etching solution, the third substrate etching step (S400) can be implemented as a step of flowing the etching solution along the scribing direction in which the first groove 2c is formed. This makes it possible to uniformly implement the ratio of the thickness of the first groove 2c (L3, shown in Figures 5B and 5C) to the thickness of the substrate 2 (L1, shown in Figures 5B and 5C) during the third substrate etching step (S400). The thickness of the first groove 2c (L3) can have the same value as the first depth and the first length.

[0050] Referring to Figures 3C and 3D, the third substrate etching step (S400) may include a step of removing particles 210 (shown in Figure 3C) formed on one surface 2a of the substrate 2. The step of removing the particles can be done by etching one surface 2a of the substrate 2. As a result, the solar cell manufacturing method according to the present invention can improve the quality of the solar cell by removing the particles 210 on the cell.

[0051] Referring to Figures 3C and 3D, the third substrate etching step (S400) may include a step of forming a substrate separation portion. The step of forming the substrate separation portion can be performed by etching one surface 2a of the substrate 2 facing the first groove 2c. Thus, the solar cell manufacturing method according to the present invention can be implemented to remove cracks 220 (shown in Figure 3C) formed on one surface 2a of the substrate 2 facing the first groove 2c. Therefore, the solar cell manufacturing method according to the present invention can improve the quality of the completed solar cell.

[0052] By performing the step of forming the substrate separation portion, a substrate separation portion 20 (shown in Figure 3D) may be formed at the location where the first groove 2c was formed. The substrate separation portion 20 may include the first groove 2c and the second groove 2d by being formed at the location where the first groove 2c and the second groove 2d were formed. The substrate separation portion 20 may be a separation portion for separating the substrate 2 for manufacturing a solar cell into multiple parts. The substrate separation portion 20 may be embodied as a groove having a larger size than each of the first groove 2c and the second groove 2d. The substrate separation portion 20 may be formed such that its size gradually decreases towards the downward direction. For example, the substrate separation portion 20 may be formed with a pointed tip that becomes sharper towards the downward direction. The substrate 2 can be separated into multiple parts via the substrate separation portion 20 formed by the third substrate etching step (S400). The substrate separation portion 20 may be embodied as a groove that is recessed to a predetermined depth from one surface 2a of the substrate 2 as a whole.

[0053] There is no particular order between the step of forming the substrate separation portion and the step of removing the particles. That is, the step of forming the substrate separation portion may be performed before the step of removing the particles, and the steps of forming the substrate separation portion and removing the particles may be performed in parallel.

[0054] Referring to Figure 3D, the step of forming the substrate separation portion may include the step of forming the first separation surface.

[0055] The step of forming the first separation surface is the step of forming a first separation surface 21 facing the substrate separation portion 20. The step of forming the first separation surface can be performed by etching one surface 2a of the substrate 2 facing the first groove 2c using the etching apparatus. By performing the step of forming the first separation surface, the first separation surface 21 can be formed so as to be inclined with respect to one surface 2a of the substrate 2.

[0056] Referring to Figure 3D, the step of forming the substrate separation portion may include the step of forming a second separation surface.

[0057] The step of forming the second separation surface is the step of forming a second separation surface 22 connected to the first separation surface 21. The second separation surface 22 may be positioned to face the substrate separation portion 20. The step of forming the second separation surface can be performed by etching one surface 2a of the substrate 2 facing the first groove 2c using the etching apparatus. By performing the step of forming the second separation surface, the second separation surface 22 may be formed to be inclined with respect to one surface 2a of the substrate 2. By performing the step of forming the second separation surface, the second separation surface 22 and the first separation surface 21 may form pointed ends that become sharper towards the downward direction and be connected to each other. That is, a corner may be formed at the connection point (CP) where the second separation surface 22 and the first separation surface 21 are connected. The connection point (CP) may be positioned at a first separation distance of approximately 46.8 μm from one surface 2a of the substrate 2 with respect to the first axial direction. The first axial direction is parallel to the direction in which the laser is irradiated, and can also be parallel to the upward direction and the downward direction, respectively.

[0058] Referring to Figure 3D, the step of forming the substrate separation portion may include the step of forming the first connecting surface.

[0059] The step of forming the first connecting surface is the step of forming a first connecting surface 23 that connects to the first separating surface 21 and one surface 2a of the substrate 2. The first connecting surface 23 may be positioned to face the substrate separating portion 20. The step of forming the first connecting surface 23 can be performed by etching one surface 2a of the substrate 2 facing the first groove 2c using the etching apparatus. By performing the step of forming the first connecting surface, the first connecting surface 23 may be positioned to be inclined with respect to one surface 2a of the substrate 2. For example, the angle between the first connecting surface 23 and one surface 2a of the substrate 2 can be approximately 90 degrees.

[0060] By performing the step of forming the first connecting surface, the angle between the first connecting surface 23 and the first separating surface 21 (θ1, shown in Figure 4) can be 180 degrees or less. By performing the step of forming the first connecting surface, a corner may be formed in the portion where the first connecting surface 23 and the first separating surface 21 are connected. The portion where the first connecting surface 23 and the first separating surface 21 are connected may be positioned to be separated from the connection point (CP) by a second separation distance of approximately 29.8 μm with respect to the first axial direction. That is, the second separation distance may be formed to be shorter than the first separation distance.

[0061] Referring to Figure 3D, the step of forming the substrate separation portion may include the step of forming the second connecting surface.

[0062] The step of forming the second connecting surface is the step of forming a second connecting surface 24 that connects to the second separating surface 22 and one surface 2a of the substrate 2. The second connecting surface 24 may be positioned to face the substrate separating portion 20. The step of forming the second connecting surface 24 can be performed by etching one surface 2a of the substrate 2 facing the first groove 2c using the etching apparatus. By performing the step of forming the second connecting surface, the second connecting surface 24 can be positioned at an inclination with respect to one surface 2a of the substrate 2. For example, the angle between the second connecting surface 24 and one surface 2a of the substrate 2 can be about 90 degrees. By performing the step of forming the second connecting surface, the second connecting surface 24 can also be positioned parallel to the first connecting surface 23. The second connecting surface 24 may be positioned at a third separation distance of about 50.8 μm from the first connecting surface 23 with respect to a second axial direction perpendicular to the first axial direction.

[0063] By performing the step of forming the second connecting surface, the angle between the second connecting surface 24 and the second separating surface 22 can be 180 degrees or less. By performing the step of forming the second connecting surface, a corner may be formed in the portion where the second connecting surface 24 and the second separating surface 22 are connected.

[0064] There is no particular order between the steps of forming the second connecting surface, the first connecting surface, the second separating surface, and the first separating surface. For example, the steps of forming the first separating surface, the second separating surface, the first connecting surface, and the second connecting surface can be performed sequentially. The steps of forming the first separating surface, the second separating surface, the first connecting surface, and the second connecting surface can also be performed in parallel.

[0065] In the following, an embodiment of the third substrate etching step (S400) using the nozzle in the method for manufacturing a solar cell according to the present invention will be described with reference to the attached figure.

[0066] First, prepare the substrate 2 as shown in Figure 3A.

[0067] Next, as shown in Figure 3B, a first substrate etching process (S200) is performed in which a laser is irradiated onto one surface 2a of the substrate 2. As a result, the first groove 2c may be formed on the substrate 2. In this case, as shown in Figure 3C, the particles 210 are formed on one surface 2a of the substrate 2, and the crack 220 may be formed on one surface 2a of the substrate 2 facing the first groove 2c.

[0068] Subsequently, the third substrate etching step (S400) is performed on one surface 2a of the substrate 2. By performing the third substrate etching step (S400), the substrate 2 is etched to a predetermined depth from one surface 2a of the substrate 2, thereby removing the particles 210 formed on one surface 2a of the substrate 2. As a result, the method for manufacturing a solar cell according to the present invention can reduce the possibility of layer shorts occurring between thin film layers formed on the substrate 2.

[0069] Subsequently, the third substrate etching step (S400) is performed up to the position where the first groove 2c is formed. By performing the third substrate etching step (S400), the substrate separation portion 20 is formed to be larger than the first groove 2c, so that one surface 2a of the substrate 2 facing the first groove 2c can be etched. As a result, the method for manufacturing a solar cell according to the present invention can be implemented to remove the crack 220.

[0070] Next, as shown in Figure 3D, the third substrate etching step (S400) is performed on the entire surface 2a of one side of the substrate 2. This completes the third substrate etching step (S400) in the solar cell manufacturing method according to the present invention.

[0071] Referring to Figures 2 and 3E, the method for manufacturing a solar cell according to the present invention may include a first thin-film layer formation step (S500).

[0072] The first thin film layer formation step (S500) is a step of forming a first thin film layer 3 on the substrate 2. By performing the first thin film layer formation step (S500), the first thin film layer 3 can be laminated on one surface 2a of the substrate 2. The first thin film layer formation step (S500) may be performed on the substrate 2 after the first substrate etching step (S200) and the third substrate etching step (S400). The first thin film layer 3 formed by the first thin film layer formation step (S500) may be a semiconductor layer formed in the form of a thin film on the substrate 2. The first thin film layer 3 can form a PN junction together with the substrate 2. Therefore, if the substrate 2 is composed of an N-type silicon wafer, the first thin film layer 3 may consist of a P-type semiconductor layer. The first thin film layer 3 can be formed using a CVD (Chemical Vapor Deposition) process or the like. The first thin film layer 3 can 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 order. When the first thin film layer 3 is formed as a PIN structure in this way, the I-type semiconductor material becomes depleted by the P-type and N-type semiconductor materials, generating an electric field inside. Holes and electrons generated by sunlight are drifted by the electric field and collected by the P-type and N-type semiconductor materials, respectively. On the other hand, when the first thin film layer 3 is formed as a PIN structure, it is preferable to form the P-type semiconductor material on top of the first thin film layer 3, followed by the I-type and N-type semiconductor materials. This is because, generally, the drift mobility of holes is lower than that of electrons, so the P-type semiconductor material is formed near the light-receiving surface to maximize the collection efficiency by incident light. On the other hand, the solar cell manufacturing method according to the present invention can also be used to form the first thin film layer 3 so that it has a stacked structure. For example, in the method for manufacturing a solar cell according to the present invention, the first thin film layer 3 can be formed to have a tandem (PIN / PIN) or triple (PIN / PIN / PIN) stacked structure.

[0073] The first thin film layer formation step (S500) may be performed on one surface 2a of the substrate 2. The first thin film layer formation step (S500) may also be performed on the other surface 2b of the substrate 2. For example, the first thin film layer formation step (S500) may be a step of forming an N-type semiconductor layer 3a (shown in Figures 6A and 6B) on one surface 2a of the substrate 2, and a P-type semiconductor layer 3b (shown in Figures 6A and 6B) on the other surface 2b of the substrate 2. When the first thin film layer 3 is laminated on both one surface 2a and the other surface 2b of the substrate 2, the first thin film layer 3 can be formed using plasma-enhanced chemical vapor deposition (PECVD) and sputtering. In this case, there is no special order between the step of forming the first thin film layer 3 on one surface 2a of the substrate 2 and the step of forming the first thin film layer 3 on the other surface 2b of the substrate 2.

[0074] Referring to Figure 3E, the first thin film layer formation step (S500) may include a step of forming a first thin film separation portion and a step of forming a first separation member.

[0075] The step of forming the first thin film separation portion is the step of forming the first thin film separation portion 30 on the first thin film layer 3. The step of forming the first thin film separation portion can be done by etching one surface of the first thin film layer 3. By performing the step of forming the first thin film separation portion, the first thin film separation portion 30 can be formed on one surface of the first thin film layer 3. The first thin film layer 3 can be separated into a plurality of parts by the first thin film separation portion 30. The first thin film separation portion 30 can be formed at a corresponding position on the substrate separation portion 20. The first thin film separation portion 30 can be a separation portion for separating a substrate for manufacturing a solar cell into a plurality of parts. The first thin film separation portion 30 can be embodied as a groove recessed to a predetermined depth from one surface of the first thin film layer 3. The size of the first thin film separation portion 30 can gradually decrease towards the downward direction.

[0076] The step of forming the first separating member is the step of forming a first separating member 31 that is inserted into the substrate separating portion 20. The step of forming the first separating member can be performed by laminating a first thin film layer 3 on the substrate 2. By performing the step of forming the first separating member, the first separating member 31 can be formed on the other surface of the first thin film layer 3. The first separating member 31 can be formed in a form corresponding to the substrate separating portion 20. For example, if the substrate separating portion 20 is formed in a shape that narrows as it goes downwards, the first separating member 31 can be formed in a shape that narrows as it goes downwards.

[0077] There is no particular order between the step of forming the first separating member and the step of forming the first thin film separating portion. For example, the step of forming the first separating member can be performed before the step of forming the first thin film separating portion, and the steps of forming the first separating member and forming the first thin film separating portion can be performed in parallel.

[0078] Referring to Figure 3F, the method for manufacturing a solar cell according to the present invention may include a second thin film layer formation step.

[0079] The second thin film layer formation step may be a step of forming a second thin film layer 4 on the first thin film layer 3. By performing the second thin film layer formation step, the second thin film layer 4 can be laminated on one surface of the first thin film layer 3. The second thin film layer formation step may be performed after the first thin film layer formation step (S500). The second thin film layer 4 formed by the second thin film layer formation step may be a transparent conductive layer. For example, the second thin film layer 4 may be a TCO (Transparent Conductive Oxide) layer. If the first thin film layer formation step (S500) is a step of forming an N-type semiconductor layer 3a (shown in Figures 6A and 6B) on one surface 2a of the substrate 2 and a P-type semiconductor layer 3b (shown in Figures 6A and 6B) on the other surface 2b of the substrate 2, then the second thin film layer formation step may be a step of forming a first TCO layer 4a (shown in Figures 6A and 6B) on the N-type semiconductor layer 3a and a second TCO layer 4b (shown in Figures 6A and 6B) on the P-type semiconductor layer 3b. The second thin film layer 4 protects the first thin film layer 3 and collects carriers generated in the substrate 2, such as holes (+), and can move the collected carriers in the upward direction. The upward direction may be the opposite direction to the downward direction. The second thin film layer can be made of a transparent conductive material such as ITO (Indium Tin Oxide), ZnOH, ZnO:B, ZnO:Al, SnO2, or SnO2:F. The second thin film layer 4 can be formed using a transparent conductive material such as ZnO, ZnO:B, ZnO:Al, or Ag, using sputtering or MOCVD methods. The second thin film layer 4 has the function of increasing the proportion of light re-incident to the first thin film layer 3 by scattering sunlight and allowing it to propagate at various angles. On the other hand, the solar cell manufacturing method according to the present invention can also form only the first thin film layer 3 without forming the second thin film layer 4. That is, the solar cell manufacturing method according to the present invention can selectively form the second thin film layer 4.

[0080] Referring to Figure 3F, the second thin film layer formation step may include the step of forming a second thin film separation portion and the step of forming a second separation member.

[0081] The step of forming the second thin film separation portion is the step of forming the second thin film separation portion 40 on the second thin film layer 4. The step of forming the second thin film separation portion can be done by etching one surface of the second thin film layer 4. By performing the step of forming the second thin film separation portion, the second thin film separation portion 40 can be formed on one surface of the second thin film layer 4. The second thin film layer 4 can be separated into multiple parts by the second thin film separation portion 40. The second thin film separation portion 40 can be formed at a corresponding position on the substrate separation portion 20. The second thin film separation portion 40 may be a separation portion for separating a substrate for manufacturing a solar cell into multiple parts. The second thin film separation portion 40 can be embodied as a groove recessed to a predetermined depth from one surface of the second thin film layer 4. The size of the second thin film separation portion 40 may gradually decrease towards the downward direction.

[0082] The step of forming the second separating member is the step of forming a second separating member 41 that is inserted into the first thin film separating portion 30. The step of forming the second separating member can be performed by laminating a second thin film layer 4 on the substrate 2. By performing the step of forming the second separating member, the second separating member 41 can be formed on the other surface of the second thin film layer 4. The second separating member 41 can be formed in a form corresponding to the first thin film separating portion 30. For example, if the first thin film separating portion 30 is formed in a form that becomes narrower as it extends downwards, the second separating member 41 can be formed in a form that becomes narrower as it extends downwards.

[0083] There is no particular order between the step of forming the second separating member and the step of forming the second thin film separating portion. For example, the step of forming the second separating member can be performed before the step of forming the second thin film separating portion, and the steps of forming the second separating member and forming the second thin film separating portion can be performed in parallel.

[0084] Referring to Figures 3D to 3G, the method for manufacturing a solar cell according to the present invention may include a cell manufacturing process.

[0085] The cell manufacturing process may be a process of forming a plurality of thin film layers on the substrate 2. By performing the cell manufacturing process, a cell 20a having a plurality of thin film layers laminated on the substrate 2 can be formed. The cell manufacturing process may be performed after the first thin film layer formation process (S500). If only two thin film layers are laminated on the substrate 2, the cell manufacturing process may be the same as the second thin film layer formation process. If N (N is an integer of 2 or more) thin film layers are laminated on the substrate 2, the method for manufacturing a solar cell according to the present invention may include a step of forming N thin film separation sections and a step of forming N separation members. Each of the thin film separation sections may be embodied in substantially the same form as the first thin film separation section 30. The separation members may be embodied in substantially the same form as the first separation member 31.

[0086] Figure 3G shows an example in which three thin film layers 3, 4, and 5 are laminated on the substrate 2, but this is illustrative, and four or more thin film layers can be laminated on the substrate 2. As shown in Figure 3G, when three thin film layers are formed on the substrate 2, the first thin film layer 3 may be an intrinsic semiconductor layer, the second thin film layer 4 may be a semiconductor layer, and the third thin film layer 5 may be a transparent conductive layer. In this case, the third thin film layer 5 may be a perovskite layer 5a (shown in Figures 6A and 6B). The first thin film layer 3 can be formed by a process of forming an I (Intrinsic) type amorphous silicon layer on one surface 2a of the substrate 2 using plasma-enhanced chemical vapor deposition.

[0087] Furthermore, Figure 3G shows an example in which three thin film layers 3, 4, and 5 are laminated on one surface 2a of the substrate 2. However, this is illustrative, and the three thin film layers 3, 4, and 5 can also be formed only on the other surface 2b of the substrate 2, or on both the one surface 2a and the other surface 2b of the substrate 2. In this case, the multiple thin film layers formed on the one surface 2a and the other surface 2b of the substrate 2 can be formed using plasma-enhanced chemical vapor deposition and sputtering. There is no particular order between the step of forming the multiple thin film layers formed on one surface 2a of the substrate 2 and the step of forming the multiple thin film layers formed on the other surface 2b of the substrate 2.

[0088] The solar cell manufacturing method according to the present invention can be implemented such that a thin-film etching step is performed continuously each time a plurality of thin-film layers are formed on the substrate 2, etching one surface of each thin-film layer. For example, after the first thin-film layer 3 is formed on the substrate 2, a step of irradiating the first thin-film layer 3 with a laser can be performed, followed by a step of etching one surface of the first thin-film layer 3. This allows the solar cell manufacturing method according to the present invention to be implemented so that particles and cracks formed on the first thin-film layer 3 are removed. Furthermore, after the second thin-film layer 4 is formed on the first thin-film layer 3, a step of irradiating the second thin-film layer 4 with a laser can be performed, followed by a step of etching one surface of the second thin-film layer 4. This allows the solar cell manufacturing method according to the present invention to be implemented so that particles and cracks formed on the second thin-film layer 4 are removed. In this way, the solar cell manufacturing method according to the present invention can be implemented so that a thin-film etching step is performed each time a thin-film layer is formed on the substrate 2, thereby improving the completeness of the etching step and improving the quality of the finished solar cell.

[0089] Referring to Figure 2, the method for manufacturing a solar cell according to the present invention may include a cell support step (S600).

[0090] The cell support step (S600) may be a step of supporting a cell 20a, which has a plurality of thin film layers formed on a substrate 2 on which the substrate separation portion 20 is formed, in the processing space. The cell support step (S600) may be performed by a cell loading device (not shown) that loads the cell 20a into the processing space. If a plurality of thin film layers are formed on the substrate 2, the cell support step (S600) may be performed after the cell manufacturing step.

[0091] Referring to Figures 2 and 7A, the method for manufacturing a solar cell according to the present invention may include a coating step (S700).

[0092] The coating step (S700) may be a step of spraying a conductive material 10b onto the cell 20a. The conductive material 10b may be a conductive material such as a transparent conductive film (TCF). The coating step (S700) may be performed after the cell support step (S600). The coating step (S700) may be performed on one surface of the cell 20a. The coating step (S700) may also be performed on another surface of the cell 20a. The coating step (S700) may be performed by a conductive material sprayer 1b installed in the processing space. The coating step (S700) may also be performed by a plurality of conductive material sprayers 1b, as shown in Figure 7A. As a result, the method for manufacturing a solar cell according to the present invention can reduce the time required for the coating step (S700) by simultaneously spraying a plurality of conductive materials 10b onto the entire surface of the cell 20a.

[0093] By performing the coating step (S700), the conductive material 10b can be sprayed onto the cell 20a. If only the first thin film layer 3 is laminated on the substrate 2, the conductive material 10b can be sprayed onto the first thin film layer 3 by performing the coating step (S700). If N thin film layers are laminated on the substrate 2, the conductive material 10b can be sprayed onto the Nth thin film layer by performing the coating step (S700).

[0094] Referring to Figures 2 and 7B, the method for manufacturing a solar cell according to the present invention includes a cutting step (S800) can be included.

[0095] The cutting step (S800) is a step of separating the cell 20a into a plurality of unit cells 20b. The cutting step (S800) may be performed after the coating step (S700). As shown in Figure 7B, when separating the cell 20a into five unit cells 20b, 20b', 20b'', 20b''', and 20b'''', the method for manufacturing a solar cell according to the present invention may include four cutting steps (S800). That is, when separating the cell into M (where M is an integer of 2 or more) unit cells 20b, the method for manufacturing a solar cell according to the present invention may include M-1 cutting steps (S800). When N thin film layers are laminated on the substrate 2, the cutting step (S800) can be performed by separating the cell 20a into the unit cells 20b through the Nth thin film separation section. For example, as shown in Figure 3G, if three thin film layers are laminated on the substrate 2, the cutting process (S800) can be performed by separating the cell 20a into the unit cell 20b via the cell separation unit 50. The cell separation unit 50 may be formed at a corresponding position on the substrate separation unit 20. The cell separation unit 50 may be a separation unit for separating a substrate for manufacturing a solar cell into multiple parts. The cutting process (S800) may be performed by a cutting robot (not shown) that separates the cell 20a into the unit cell 20b.

[0096] Referring to Figures 2 and 7C, the method for manufacturing a solar cell according to the present invention may include a bonding step (S900).

[0097] The bonding step (S900) is a step of bonding the separated unit cells 20b. The bonding step (S900) can be performed by bonding the separated unit cells 20b via the conductive material 10b. If the cell 20a is separated into five unit cells 20b, 20b', 20b'', 20b'''', and 20b'''' via the cutting step (S800), the method for manufacturing a solar cell according to the present invention can include four bonding steps (S900), as shown in Figure 7C. In other words, if M (where M is an integer of 2 or more) unit cells 20b are to be bonded, the method for manufacturing a solar cell according to the present invention can include M-1 bonding steps (S900). The joining process (S900) may include, as shown in Figure 7C, a step of joining one face on one side of the first unit cell 20b to the other face on one side of the second unit cell 20b', a step of joining one face on the other side of the second unit cell 20b' to the other face on one side of the third unit cell 20b'', a step of joining one face on the other side of the third unit cell 20b'' to the other face on one side of the fourth unit cell 20b''', and a step of joining one face on the other side of the fourth unit cell 20b''' to the other face on one side of the fifth unit cell 20b''''. The two sides of each unit cell 20b may be positioned opposite each other with respect to the midpoint of the unit cell 20b. The joining process (S900) may be performed by a transfer robot (not shown) that moves the unit cells 20b.

[0098] Referring to Figures 2 and 7C, the method for manufacturing a solar cell according to the present invention may include a curing step (S1000).

[0099] The curing step (S1000) is a step of hardening the bonded unit cells 20b. The curing step (S1000) may be performed after the bonding step (S900). The curing step (S1000) may be performed using a heating device (not shown) to heat the bonded unit cells 20b. By performing the curing step (S1000), a solar cell 1 in the form of a module in which the unit cells 20b are connected to each other can be manufactured. Figure 7C shows that the solar cell 1 is composed of five unit cells 20b, but this is illustrative, and the solar cell 1 may be composed of two to four unit cells 20b, or six or more unit cells 20b.

[0100] A method for manufacturing a solar cell according to one embodiment of the present invention may include the steps of preparing a substrate and forming a thin film.

[0101] The step of preparing the substrate may be a step of preparing a substrate 2 on which a substrate separation portion 20 including the first groove 2c and the second groove 2d is formed. The step of preparing the substrate may be performed after the substrate support step (S100) and before the first thin film layer formation step (S500). The step of preparing the substrate may include the first substrate etching step (S200), the second substrate etching step (S300), and the third substrate etching step (S400). The step of preparing the substrate may be performed by the scribing apparatus 1a and the etching apparatus (not shown).

[0102] The step of forming the thin film is a step of forming a thin film layer on the substrate 2 on which the substrate separation portion 20 is formed. The step of forming the thin film may be performed after the step of preparing the substrate. When only the first thin film layer 3 is laminated on the substrate 2, the step of forming the thin film may be implemented in substantially the same manner as the first thin film layer formation step (S500). When a plurality of thin film layers are laminated on the substrate 2, the step of forming the thin film may be implemented in substantially the same manner as the cell manufacturing step.

[0103] A modified embodiment of the present invention can include a method for manufacturing a solar cell, comprising the substrate support step (S100), a first substrate etching step (S200), a third substrate etching step (S400), and a step for forming a solar cell. The substrate support step (S100), the first substrate etching step (S200), and the third substrate etching step (S400) are implemented in substantially the same manner as described above, so the differences will be explained below.

[0104] The first substrate etching step (S200) may be a step of forming a plurality of linear grooves on the upper surface of the substrate 2. The linear grooves formed by the first substrate etching step (S200) may be substrate separation portions 20 for separating the substrate into a plurality of parts. The first substrate etching step (S200) may be performed after the substrate support step (S100). The upper surface of the substrate 2 may be the same surface as one surface 2a of the substrate 2.

[0105] The third substrate etching step (S400) may be a step of etching the upper surface of the substrate 2 and the plurality of linear grooves. The third substrate etching step (S400) may be performed after the first substrate etching step (S200). The third substrate etching step (S400) may be performed by the etching apparatus.

[0106] The step of forming the solar cell may be a step of forming a plurality of thin film layers on the upper surface of the substrate 2. The step of forming the solar cell may be performed after the third substrate etching step (S400). When only one thin film layer is laminated on the upper surface of the substrate 2, the step of forming the solar cell may be implemented in substantially the same manner as the first thin film layer formation step (S500). When a plurality of thin film layers are laminated on the upper surface of the substrate 2, the step of forming the solar cell may be implemented in substantially the same manner as the cell manufacturing step.

[0107] A method for manufacturing a solar cell according to another modified embodiment of the present invention may include a substrate preparation step, a solar cell formation step, and a separation step. The solar cell formation step has already been described in detail above, so a detailed explanation will be omitted below.

[0108] The substrate preparation step may be a step of preparing a substrate 2 having a plurality of linear grooves formed on its upper surface. The substrate preparation step may be a step of preparing the substrate 2, which has undergone the substrate support step (S100), the first substrate etching step (S200), and the third substrate etching step (S400), in the processing space. The substrate preparation step may be performed after the third substrate etching step (S400).

[0109] The separation step may be a step of separating the substrate 2 by the plurality of linear grooves. The separation step may be performed after the solar cell formation step. The separation step may be implemented in substantially the same manner as the cutting step (S800).

[0110] Another modified embodiment of the present invention relates to a method for manufacturing a solar cell, which may include the substrate preparation step, the coating step (S700), and the cutting step (S800). Since the substrate preparation step, the coating step (S700), and the cutting step (S800) have already been described, the differences will be explained below.

[0111] The substrate preparation step may be a step of preparing a substrate on which solar cells are formed, wherein a plurality of linear grooves are formed on the upper surface of the substrate 2. That is, the substrate preparation step may be a step of preparing a substrate on which a plurality of linear grooves are formed and one or more thin film layers are laminated. The substrate preparation step may be performed after the step of forming the solar cells.

[0112] The coating step (S700) may be a step of applying a conductive material 10b around the plurality of linear grooves. The coating step (S700) may be performed after the substrate preparation step.

[0113] The cutting step (S800) may be a step of separating the substrate 2 into two parts along any of the plurality of linear grooves. The cutting step (S800) may be performed after the coating step (S700). Each of the two parts separated by the cutting step (S800) may be embodied in substantially the same form as the unit cell 20b.

[0114] In the following, the solar cell according to the present invention will be described in detail with reference to the attached figures.

[0115] The solar cell 1 according to the present invention produces electricity using light energy. The solar cell 1 according to the present invention (shown in Figures 3E to 3F) can be manufactured by the solar cell manufacturing method according to the present invention. The solar cell 1 according to the present invention can be manufactured by completing the cell manufacturing process.

[0116] Referring to Figures 3E to 3F, the solar cell 1 according to the present invention may include the substrate 2 and the first thin film layer 3.

[0117] The substrate 2 may have a predetermined electrical conductivity polarity. The substrate 2 may be made of a silicon wafer. The first thin film layer 3 may be laminated on one surface 2a of the substrate 2. The substrate separation portion 20 of the substrate 2 may be formed on one surface 2a of the substrate 2. The size of the substrate separation portion 20 may gradually decrease towards the downward direction. The substrate separation portion 20 may be formed by performing the first substrate etching step (S200).

[0118] The first thin film layer 3 is formed on the substrate 2. The first thin film layer 3 can be laminated on one surface 2a of the substrate 2. The first separating member 31 of the first thin film layer 3 can be inserted into the substrate separating portion 20. The first separating member 31 can be formed in a form corresponding to the substrate separating portion 20. For example, the first separating member 31 can be formed such that its size gradually decreases towards the downward direction. The first separating member 31 can be formed by performing the first thin film layer formation step (S500).

[0119] In the above description, the solar cell 1 according to the present invention was explained based on the assumption that it includes the substrate 2 and the first thin film layer 3. However, this is illustrative, and the solar cell 1 according to the present invention may include the substrate 2 and two thin film layers 3 and 4, as shown in Figure 3f, and may also include the substrate 2 and three thin film layers 3, 4, and 5, as shown in Figure 3g.

[0120] In the following section, an embodiment of the solar cell 1 according to the present invention, in which multiple thin film layers are formed on the substrate 2, will be specifically described with reference to the attached figure.

[0121] Referring to Figures 6A and 6B, the solar cell 1 according to the present invention may include the substrate 2, an N-type semiconductor layer 3a laminated on the upper surface of the substrate 2, a first TCO layer 4a laminated on the N-type semiconductor layer 3a, a perovskite layer 5a laminated on the first TCO layer 4a, a P-type semiconductor layer 3b laminated on the lower surface of the substrate 2, and a second TCO layer 4b laminated on the P-type semiconductor layer 3b. In this case, the cell separation portion 50 may be formed on the lower surface 2b of the substrate 2. Thus, compared to the example in which the cell separation portion 50 is formed on the upper surface 2a of the substrate 2, the solar cell 1 according to one embodiment of the present invention can embody a preventive force that prevents the perovskite material, TCO material, and N-type semiconductor material from flowing onto the cell separation portion 50 due to gravity when the scribing process is performed.

[0122] In the following description, a solar cell according to one embodiment of the present invention will be explained with reference to the attached figure.

[0123] Referring to Figures 7C and 8, a solar cell 10 according to one embodiment of the present invention (shown in Figure 7C) can be manufactured by the solar cell manufacturing method according to the present invention. The solar cell 10 according to one embodiment of the present invention can be manufactured by completing the curing process (S1000). The solar cell 10 according to one embodiment of the present invention can be realized in a module form in which the unit cells 20b are connected to each other. Hereinafter, each of the plurality of unit cells 20b of the solar cell 10 according to one embodiment of the present invention will be specifically described with reference to the attached figures.

[0124] Referring to Figure 8, each of the unit cells 20b may include a cell top surface 20b1, a cell cutting groove 20b2, a first cutting surface 20b3, a second cutting surface 20b4, and a third cutting surface 20b5.

[0125] The cell upper surface 20b1 is positioned to face upward. The cell upper surface 20b1 can correspond to one surface of the unit cell 20b positioned to face upward. The conductive material 10b can be sprayed onto the cell upper surface 20b1. When N thin film layers are laminated on the substrate 2, the cell upper surface 20b1 may be the same surface as one surface of the Nth thin film layer.

[0126] The cell cutting groove 20b2 is formed when the cell 20a is separated into a plurality of unit cells 20b. The cell cutting groove 20b2 may be part of the cell separation portion 50. The cell cutting groove 20b2 is formed on the cell upper surface 20b1. The cell cutting groove 20b2 may be formed by recessing from the cell upper surface 20b1 to a predetermined depth. The cell cutting groove 20b2 may be represented as a groove whose size decreases as it extends downward.

[0127] The first cutting surface 20b3 is positioned to face the cell cutting groove 20b2. The first cutting surface 20b3 can be connected to the second cutting surface 20b4. An angle may be formed at the point where the first cutting surface 20b3 and the second cutting surface 20b4 are connected. The first cutting surface 20b3 can be positioned to be inclined with respect to the cell upper surface 20b1. The first cutting surface 20b3 can be connected to the second cutting surface 20b3 and the third cutting surface 20b4, respectively.

[0128] The second cross-section 20b4 is connected to the first cross-section 20b3 and the cell upper surface 20b1, respectively. The angle between the second cross-section 20b4 and the first cross-section 20b3 (θ2, shown in Figure 8) can be less than 180 degrees. The second cross-section 20b4 can be positioned at an angle with respect to the first cross-section 20b3 and the cell upper surface 20b1, respectively. An angle can be formed at the point where the second cross-section 20b4 and the cell upper surface 20b1 are connected. The angle between the second cross-section 20b4 and the cell upper surface 20b1 can be approximately 90 degrees.

[0129] The third cross-section 20b5 is connected to the first cross-section 20b3 and the lower surface of the cell, respectively. The third cross-section 20b5 may be formed by separating the cell 20a into the unit cell 20b. The third cross-section 20b5 may be formed planarly. The lower surface of the cell may correspond to the other surface of the unit cell 20b which is positioned to face downward. An angle may be formed in the portion where the third cross-section 20b5 and the first cross-section 20b3 are connected. The third cross-section 20b5 may be positioned to be inclined with respect to the first cross-section 20b3 and the lower surface of the cell, respectively. An angle may be formed in the portion where the third cross-section 20b5 and the lower surface of the cell are connected.

[0130] The following will provide a detailed explanation with reference to the attached diagram of the solar cell substrate 2 according to the present invention.

[0131] Referring to Figures 5A to 5D, the solar cell substrate 2 according to the present invention is formed by performing the first substrate etching step (S200) before the third substrate etching step (S400). The solar cell substrate 2 according to the present invention may include a substrate body, a first groove 2c, a second groove 2d, and a damage prevention portion 2f.

[0132] The substrate body has a predetermined electrical conductivity polarity. The substrate body can function as the main body of the solar cell substrate 2 according to the present invention. The substrate body can form the overall external shape of the solar cell substrate 2 according to the present invention.

[0133] The first groove 2c is formed in the substrate body. The first groove 2c can be formed by etching one surface 2a of the substrate body to a predetermined depth. The first groove 2c can be formed in an overall rectangular parallelepiped shape. The first groove 2c can be formed by performing the first substrate etching step (S200).

[0134] The second groove 2d is formed inside the first groove 2c. That is, the second groove 2d can communicate with the first groove 2c. The second groove 2d is for expanding the etching surface 2e facing the first groove 2c. As a result, the solar cell substrate 2 according to the present invention can improve the overall quality of the finished solar cell by expanding the etching surface 2e, which has a better quality cross-section than the substrate cut surface 2g. The second groove 2d may be formed in an overall rectangular parallelepiped shape. The second groove 2d may be formed by performing the second substrate etching process (S300).

[0135] The damage prevention portion 2f is formed such that a step is created with respect to the etching surface 2e, and the second groove 2d is formed on the inside. By restricting the expansion of the etching surface 2e, the damage prevention portion 2f can embody a preventative force that prevents the solar cell substrate 2 according to the present invention from being damaged in multiple parts. As a result, the solar cell substrate 2 according to the present invention is less likely to be damaged even if physical impact occurs, such as colliding with process equipment installed in the processing space, thereby improving process stability for solar cell manufacturing.

[0136] The damage prevention portion 2f may be formed to be smaller in size than the second groove 2d, with reference to the scribing direction in which the first groove 2c is formed. That is, the second groove 2d may be formed to be larger in size than the damage prevention portion 2f, with reference to the scribing direction. As a result, the solar cell substrate 2 according to the present invention can increase the expanded area of ​​the etching surface 2e.

[0137] The damage prevention portion 2f may be formed with a second thickness (L2, shown in Figures 5B and 5C) which is 1 / 2 or more of the first thickness (L1, shown in Figures 5B and 5C) of the substrate body, and less than or equal to the first thickness (L1). This ensures that the solar cell substrate 2 according to the present invention has sufficient protection against separation into multiple parts. The thickness may be parallel to the direction in which the overall height of the solar cell substrate 2 according to the present invention increases or decreases, and perpendicular to the scribing direction. The second thickness (L2) may be 70% or more of the first thickness (L1). In this case, the third thickness (L3, shown in Figures 5B and 5C) between the damage prevention portion 2f and one surface 2a of the substrate 2 may be 30% or less of the first thickness (L1). The damage prevention portion 2f may be formed protruding from the etching surface 2e.

[0138] The damage prevention section 2f may include a first prevention member 2f1, a second prevention member 2f2, and a connecting member 2f3.

[0139] The first protective member 2f1 is formed such that a step is created with respect to the etched surface 2e. The first protective member 2f1 is formed on one side of the second groove 2d and can prevent damage to the solar cell substrate 2 according to the present invention. The first protective member 2f1 can be formed in an overall rectangular parallelepiped shape.

[0140] The second prevention member 2f2 is formed at a position separated from the first prevention member 2f1. The second prevention member 2f2 may be formed such that a step is created with respect to the etching surface 2e. The second prevention member 2f2 is formed on the other side of the second groove 2d and can prevent damage to the solar cell substrate 2 according to the present invention. The second prevention member 2f2 may be formed in an overall rectangular parallelepiped shape.

[0141] The connecting member 2f3 is connected to the first prevention member 2f1 and the second prevention member 2f2, respectively. The second groove 2d can be located inside the connecting member 2f3, the second prevention member 2f2, and the first prevention member 2f1. The connecting member 2f3 may be formed in an overall rectangular parallelepiped shape.

[0142] The connecting member 2f3 can be connected to the first prevention member 2f1 and the second prevention member 2f2 in such a way that a step is created between them. For example, the angle between the connecting member 2f3 and the first prevention member 2f1 and the angle between the connecting member 2f3 and the second prevention member 2f2 can each be 90 degrees. The connecting member 2f3 can also be connected to the first prevention member 2f1 and the second prevention member 2f2 in such a way that it forms a curved surface.

[0143] The present invention described above is not limited to the embodiments and accompanying figures, and it will be apparent to those with ordinary skill in the art to which the present invention pertains that multiple substitutions, modifications, and alterations are possible without departing from the technical spirit of the present invention.

Claims

1. A substrate having electrical conductivity polarity, and The substrate includes a first thin film layer formed on the substrate, A substrate separation section is formed on one surface of the substrate for separating the substrate into a plurality of unit cells. The substrate separation portion is formed such that its size gradually decreases as it extends downwards. The first thin film layer includes a first separation member inserted into the substrate separation portion, Each of the aforementioned plurality of unit cells is The top surface of the cell is positioned to face upwards. Cell cutting groove formed on the upper surface of the cell, A first cutting surface, positioned to face the cell cutting groove, A second cross-section connected to the first cross-section and the upper surface of the cell, and A third cross-section connected to the first cross-section and the lower surface of the cell, Includes, A first corner is formed at the portion where the first cross-section and the second cross-section are connected. A second corner is formed at the portion where the second cross-section and the upper surface of the cell are connected. A third corner is formed at the portion where the first cross-section and the third cross-section are connected. A fourth corner is formed at the point where the third cross-section and the lower surface of the cell are connected. The aforementioned substrate, A substrate body having electrical conductivity polarity, A first groove is formed extending from one side to the other side of the substrate body. A second groove is connected to the first groove so as to expand the etching surface facing the first groove, and The etching surface is formed to create a step, and the damage prevention portion is formed with the second groove facing inward. The second groove is not provided on one side and the other side of the substrate body, and the damage prevention portion is provided on one side and the other side of the substrate body. A solar cell characterized by the following features.

2. The solar cell according to claim 1, characterized in that the angle between the first cross-section and the second cross-section is less than 180 degrees.

3. The solar cell according to claim 1, characterized in that the second groove is formed to be larger in size than the damage prevention portion with respect to the scribe direction in which the first groove is formed.

4. The solar cell according to claim 1, characterized in that the damage prevention portion is formed with a second thickness having a value of 1 / 2 or more of the first thickness of the substrate body and a value less than or equal to the first thickness.

5. The damage prevention portion is formed such that a step is created with respect to the etched surface, and includes a first prevention member, a second prevention member formed at a position separated from the first prevention member, and connecting members connected to the first prevention member and the second prevention member, The solar cell according to claim 1, characterized in that the connecting member is connected such that a step is created between the first prevention member and the second prevention member.

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