KR20120026174A - Solar cell - Google Patents

Abstract

PURPOSE: A solar cell is provided to prevent a crack generated in a manufacturing process by forming a electrode pattern to be parallel with the longitudinal side and horizontal side of a substrate. CONSTITUTION: A first electrode(141) and a second electrode(142) are formed in the rear side of a substrate(110). The first electrode comprises a first electrode connecting part(BA1) and a plurality of first electrode slines(FA1). The second electrode comprises a 2A electrode connecting part(BA2) and a plurality of 2A electrode lines(FA2). The plural 2A electrode lines are electrically connected to each other through the 2A electrode connecting part. A part of the first electrode and the second electrode are not partly parallel with the longitudinal side or the length side of the substrate.

Description

Solar cell {SOLAR Cell}

The present invention relates to a solar cell.

With the recent prediction of the depletion of existing energy resources such as oil and coal, there is a growing interest in alternative energy to replace them, and accordingly, solar cells that produce electric energy from solar energy are attracting attention.

A typical solar cell includes a substrate and an emitter layer made of semiconductors of different conductive types, such as p-type and n-type, and electrodes connected to the substrate and the emitter, respectively. At this time, p-n junction is formed in the interface of a board | substrate and an emitter part.

When light is incident on the solar cell, a plurality of electron-hole pairs are generated in the semiconductor, and the generated electron-hole pairs are separated into electrons and holes charged by the photovoltaic effect, respectively, and the electrons and holes are n-type. Move toward the semiconductor and the p-type semiconductor, for example toward the emitter portion and the substrate, respectively, and are collected by electrodes electrically connected to the substrate and the emitter portion, which are connected by wires to obtain power.

The present invention provides a solar cell in which the electrode pattern formed on the rear surface of the substrate is not parallel to the longitudinal side or the horizontal side of the substrate.

The solar cell according to an example of the present invention has at least a substrate having a first conductive type of a rectangular shape having a horizontal side in the horizontal direction and a vertical side in the longitudinal direction, and having a second conductive type connected to the substrate and opposite to the first conductive type. And one emitter portion, a first electrode connected to the at least one emitter portion, and a second electrode electrically connected to the substrate, wherein at least some of each of the first electrode and the second electrode is disposed on a longitudinal side or a horizontal side of the substrate. It is formed so as not to be parallel to.

Here, the longitudinal direction of at least some of each of the first electrode and the second electrode is greater than 0 ° and less than 90 °, greater than 90 ° and less than 180 °, less than 180 ° and less than 270 ° with respect to the horizontal surface or the longitudinal side of the substrate, It may be formed within an angle range of more than 270 ° and less than 360 °.

In addition, at least some of each of the first electrode and the second electrode may be formed to be parallel to each other.

In addition, at least some of each of the first electrode and the second electrode may be alternately formed.

Here, the first electrode includes a first A electrode connecting portion formed in parallel to the horizontal side or the vertical side of the substrate; And a plurality of first A electrode lines extending from the first A electrode connection portion so as not to be parallel to the longitudinal side or the horizontal side of the substrate, wherein the second electrode is disposed on the opposite side or the horizontal side of the first A electrode connection portion on the substrate. A second A electrode connection portion formed adjacent to and in parallel; And a plurality of second A electrode lines extending from the second A electrode connection portion and not formed to be parallel to the longitudinal side or the horizontal side of the substrate.

Here, the first A electrode connecting portion may connect the plurality of first A electrode lines to each other, and the second A electrode connecting portion may connect the plurality of second A electrode lines to each other.

In addition, the width of the first A electrode connection portion and the second A electrode connection portion may be substantially the same.

In addition, the width of each of the plurality of first A electrode lines and the plurality of second A electrode lines may be smaller than the width of each of the first A electrode connection part and the second A electrode connection part.

In addition, the widths of the plurality of first A electrode lines may be greater than the widths of the plurality of second A electrode lines.

In addition, the first electrode may include a first B electrode connecting portion extending in a diagonal direction from an end of the first A electrode connecting portion formed at an edge of the substrate; And a plurality of first B electrode lines extending from the first B electrode connecting portion so as not to be parallel to the longitudinal side or the horizontal side of the substrate, wherein the second electrode is formed from an opposite diagonal edge of the end of the first B electrode connecting portion. A second B electrode connecting portion extending in an end direction of the 1B electrode connecting portion; And a plurality of second B electrode lines extending from the second B electrode connection portions so as not to be parallel to the longitudinal side or the horizontal side of the substrate.

Here, the plurality of first A electrode lines and the plurality of second B electrode lines may be alternately arranged side by side, and the plurality of second A electrode lines and the plurality of first B electrode lines may be alternately arranged side by side.

In addition, each of the widths of the first B electrode connection part and the second B electrode connection part may be greater than the width of each of the plurality of first B electrode lines and the plurality of second B electrode lines.

In addition, the widths of the plurality of first A electrode lines may be greater than the widths of the plurality of second B electrode lines.

Also, the width of the plurality of first B electrode lines may be greater than the width of the plurality of second A electrode lines.

In addition, the plurality of first and second electrode lines may be formed at different angles according to regions on the substrate.

Specifically, the first electrode includes a plurality of first extending in the diagonal direction of the horizontal side where the first C electrode connecting portion extending from the middle portion of the first B electrode connecting portion in the corner direction of the second A electrode connecting portion and the second A electrode connecting portion formed from the first C electrode connecting portion. Further comprising a 1C electrode line, the second electrode is a diagonal direction of the horizontal side formed with the 2C electrode connecting portion extending from the middle portion of the second B electrode connecting portion in the corner direction of the first A electrode connecting portion and the 1A electrode connecting portion from the second C electrode connecting portion. It may further include a plurality of first C electrode lines extending to.

Here, the extending direction of the plurality of first C electrode lines is different from the extending direction of some of the plurality of first A electrode lines and the plurality of first B electrode lines, and the extending direction of the plurality of second C electrode lines is the plurality of second A electrode lines. Some of the plurality of second BB electrodes and the extending direction of the line may be formed differently.

In addition, the solar cell according to another embodiment of the present invention is at least one emitter portion connected to the substrate and having a second conductivity type opposite to the first conductivity type, a first electrode connected to the at least one emitter portion, and And a second electrode electrically connected to the substrate, wherein at least some of each of the first electrode and the second electrode is formed in a diagonal direction and a crystal direction of the single crystal silicon included in the substrate.

Here, the first electrode further comprises a first electrode connecting portion formed in a direction parallel to the crystal direction of the single crystal silicon included in the substrate to connect each of the plurality of first electrode lines, the second electrode is a first electrode connecting portion in the substrate Opposite of the may further include a second electrode connecting portion formed in a direction parallel to the crystal direction of the single crystal silicon to connect each of the plurality of second electrode lines.

As described above, the solar cell according to the exemplary embodiment of the present invention is formed so that the electrode patterns formed on the rear surface of the substrate are not parallel to the longitudinal side or the horizontal side of the substrate, thereby preventing cracks that may occur during the manufacturing process, thereby improving process yield. In addition, there is an effect of improving the efficiency by shortening the moving path of the carrier.

1 is a partial perspective view of a solar cell according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view of the solar cell shown in FIG. 1 taken along line II-II.
3 and 4 illustrate the first example of the arrangement of the first electrode 141 and the second electrode 142 formed on the rear surface of the substrate 110 in the solar cell according to the embodiment of FIG. 1 in more detail. It is for the purpose.
5 and 6 will be described in more detail a second example of the arrangement of the first electrode 141 and the second electrode 142 formed on the rear surface of the substrate 110 in the solar cell according to the embodiment of FIG. It is for the purpose.
7 and 8 illustrate a third example of the arrangement of the first electrode 141 and the second electrode 142 formed on the rear surface of the substrate 110 in the solar cell according to the embodiment of FIG. 1 in more detail. It is for the purpose.
9 and 10 are diagrams for explaining in detail the solar cell according to the second embodiment of the present invention.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted for simplicity of explanation, and like reference numerals designate like parts throughout the specification.

Hereinafter, a solar cell module and a manufacturing method thereof according to an embodiment of the present invention will be described with reference to the accompanying drawings.

First, a solar cell according to a first embodiment of the present invention will be described in detail with reference to FIGS. 1 and 2.

1 is a partial perspective view of a solar cell according to a first exemplary embodiment of the present invention, and FIG. 2 is a cross-sectional view of the solar cell shown in FIG. 1 taken along the line II-II.

1 and 2, a solar cell 1 according to an exemplary embodiment of the present invention includes a substrate 110 and a surface of the substrate 110 to which light is incident (hereinafter, referred to as a 'front surface'). 'Front' electric field unit 171, front protective unit 191 positioned on the front electric field unit 171, the anti-reflection film 130 positioned on the front protective unit 191, the light is not incident A plurality of emitter portions 121, a plurality of rear electric field portions 122, and a plurality of emitter portions 121 positioned on a surface of the substrate 110 facing the front surface of the substrate 110 (hereinafter, referred to as a “rear surface”). A rear protection unit 192 positioned on a part of the emitter unit 121 and a plurality of rear electric field units 122, a first electrode 141 connected to the exposed plurality of emitter units 121, and an exposure The second electrode 142 is connected to the plurality of rear electric field 122.

The substrate 110 is a semiconductor substrate made of silicon of a first conductivity type, for example, an n-type conductivity type. In this case, since the substrate 100 has an n-type conductivity type, the substrate 110 may be formed of 5, such as nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb), and bismuth (Bi). It may contain impurities of the element. The substrate 110 has a rectangular shape having a horizontal side in the horizontal direction and a vertical side in the vertical direction.

Alternatively, the substrate 110 may be of a p-type conductivity type, in which case the substrate 110 may be boron (B), aluminum (Na), gallium (Ga), indium (In), or titanium (Ti). It may contain impurities of trivalent elements such as the like. In another embodiment, the substrate 110 may be made of a semiconductor material other than silicon.

The upper surface of this substrate 110 is textured to have a textured surface that is an uneven surface. As a result, the light reflectance at the upper surface of the substrate 110 is reduced, and a plurality of incidence and reflection operations are performed on the uneven surface to trap the light inside the solar cell 1, thereby increasing the light absorption rate. The efficiency of the battery 1 is improved.

The front electric field part 171 located on the front surface of the substrate 100, which is an uneven surface, is present in the substrate 110, and an impurity portion in which impurities of the same conductivity type as the substrate 110 are contained at a higher concentration than the substrate 110, eg, For example, n + part.

Therefore, a potential barrier is formed due to the difference in the impurity concentration between the substrate 110 and the front surface electric field unit 171, thereby preventing hole movement toward the front surface of the substrate 110. Recombine to reduce extinction.

The substrate 110 may be a single crystal silicon substrate having a constant crystal direction.

Thus, when the substrate 110 is a single crystal silicon substrate as described above, when the substrate is processed to form a unit cell of the solar cell during the manufacturing process, the substrate 110 may be cut in the vertical direction or the vertical direction according to the crystal direction.

For example, when the substrate 110 is a P-type and the crystal direction is 100, when the substrate 110 is cut, the shape of the substrate 110 is longitudinally and horizontally along the crystal direction 100. It can be cut. As described above, the substrate 110 is cut along the crystal direction in the vertical direction and the horizontal direction so that the vertical side and the horizontal side are formed on the substrate 110.

This is because cutting the substrate 110 along the crystal direction is not only easy to cut, but also because the cutting line is the same as the crystal direction and thus can be more accurately cut.

The front protective part 191 positioned on the front electric field 171 converts an unstable bond such as a dangling bond, which exists near the surface of the substrate 110, into a stable bond, thereby causing the substrate 110 to be unstable. Reduces the charge that has moved towards the front of, for example, the disappearance of electrons.

The front protection part 191 is made of silicon oxide (SiOx) or the like.

The anti-reflection film 130 disposed on the passivation layer 191 may be formed of a hydrogenated silicon nitride layer (SiNx: H) or the like. The anti-reflection film 130 reduces the reflectivity of light incident on the solar cell 1 and increases the selectivity of a specific wavelength region, thereby increasing the efficiency of the solar cell 1. In the present embodiment, the anti-reflection film 130 may have a single film structure but may have a multilayer film structure such as a double film, and may be omitted as necessary.

The plurality of emitter portions 121 positioned in the rear surface of the substrate 110 are spaced apart from each other and extend in parallel to each other in a predetermined direction.

The plurality of emitter portions 121 contains a second conductivity type, for example, p-type impurities (p ++), which are opposite to the conductivity type of the substrate 110 at a high concentration, thereby forming a pn junction with the substrate 100. do. Therefore, the emitter unit 120 includes impurities of trivalent elements such as boron (B), gallium (Ga), indium (In), and the like. The plurality of emitters 121 may be formed by containing a high concentration of p-type impurities p ++, which is a second conductivity type opposite to the conductivity type of the crystalline silicon substrate 110, through a diffusion process.

The plurality of backside electric fields 122 located in the rear surface of the substrate 110 are separated from the plurality of emitter portions 121 and extend in the same direction as the plurality of emitter portions 121 substantially parallel to each other. Thus, as shown in FIGS. 1 and 2, the plurality of emitter portions 121 and the plurality of rear electric field portions 171 are alternately positioned on the rear surface of the substrate 110.

The plurality of backside electric fields 122 is an impurity, for example, n ++ part, in which impurities of the same conductivity type as the substrate 110 are contained at a higher concentration than the substrate 110. The plurality of back surface fields 122 may be formed by containing impurities (n ++) of the same conductivity type as that of the crystalline silicon substrate 110 at a high concentration through diffusion identification.

Thus, similar to the front electric field part 171, a potential barrier is formed due to the difference in the impurity concentration between the substrate 110 and the plurality of rear electric field parts 122, and the holes moved toward the rear electric field part 122 are moved. Movement toward the electrode 142 is prevented, so that the amount of electrons and holes recombined and disappears in the vicinity of the second electrode 142 is reduced.

As such, the electron-hole pair is an electric charge generated by light incident on the substrate 110 due to a built-in potential difference due to a pn junction formed between the substrate 110 and the plurality of emitter portions 121. Is separated into electrons and holes, electrons move toward n-type and holes move toward p-type. Therefore, when the substrate 110 is n-type and the plurality of emitter portions 121 are p-type, the separated holes move toward each emitter portion 121 and the separated electrons move toward the plurality of rear electric field portions 122. .

Since each emitter portion 121 forms a pn junction with the substrate 110, unlike the present embodiment, when the substrate 110 has a p-type conductivity type, the plurality of emitter portions 121 are n-type conductivity. Has type In this case, the separated electrons move toward the plurality of emitter parts 121, and the separated holes move toward the plurality of rear electric field parts 172.

The back protection part 192 is made of a silicon oxide film (SiOx) or the like, similar to the front protection part 191, and replaces an unstable bond which exists near the back of the substrate 110 to a stable bond, toward the rear side of the substrate 110. It reduces the dissipation of the charged charge by unstable bonds.

The rear protection unit 192 may include a plurality of openings 1921 exposing portions of the plurality of emitter units 121 and portions of the plurality of rear electric fields 122. Each opening 1921 may be provided. It has a stripe shape extending along the plurality of emitters 121 and the plurality of rear electric field 122.

The rear protection unit 192 may include a plurality of emitter units 121. The first electrode 141, which is physically and electrically connected to the plurality of emitter units 121 exposed through the plurality of openings 1921, respectively. Accordingly, the second electrode 142, which is physically and electrically connected to the plurality of rear electric fields 122 exposed through the plurality of openings 1921, extends along the plurality of rear electric fields 122. .

Here, the first electrode 141 and the second electrode 142 are physically and electrically isolated from each other on the rear surface of the substrate 110, and as shown between the first electrode 141 and the second electrode 142. It may be insulated by the back protection 192.

Accordingly, the first electrode 141 formed on the emitter portion 121 collects charges, for example, holes, which have moved toward the emitter portion 121, and the second electrode (141) formed on the rear electric field portion 122. 142 collects charge, eg, electrons, that have migrated toward the corresponding backside field 122.

As such, the holes collected through the first electrode 141 and the electrons collected through the second electrode 142 are used as power of the external device through an external circuit device.

On the other hand, at least some of each of the first electrode 141 and the second electrode 142 formed on the rear surface of the substrate 110 is formed not parallel to the vertical side or the horizontal side of the substrate 110. That is, at least a portion of the first electrode 141 and the second electrode 142 may be formed in an oblique direction with a side line of the substrate 110. A more detailed description thereof will be described in more detail with reference to FIG. 3.

The solar cell 1 according to the present exemplary embodiment having the structure as described above is a solar cell in which the first electrode 141 and the second electrode 142 are positioned on the rear surface of the substrate 110 to which light is not incident. Is as follows.

When light is irradiated onto the solar cell 1 and sequentially passes through the anti-reflection film 130, the front protective part 191, and the front electric field part 171 and enters the substrate 110, the light is radiated from the substrate 110 by light energy. Electron-hole pairs occur. At this time, since the surface of the substrate 110 is a texturing surface, the light reflectivity on the entire surface of the substrate 110 is reduced, and incident and reflection operations are performed on the texturing surface to increase light absorption, thereby improving efficiency of the solar cell 1. do. In addition, the reflection loss of light incident on the substrate 110 by the anti-reflection film 130 is reduced, so that the amount of light incident on the substrate 110 is further increased.

These electron-hole pairs are separated from each other by the pn junction of the substrate 110 and the emitter portion 121 so that the holes move toward a plurality of emitter portions 121 having a p-type conductivity type, and the electrons are n-type conductivity. It is moved toward a plurality of rear electric field 122 having a type, and collected by the first electrode 141 and the second electrode 142, respectively. When the first electrode 141 and the second electrode 142 are connected with a conductive wire, a current flows, which is used as power from the outside.

In this case, since the passivation layers 192 and 191 are positioned not only on the rear surface of the substrate 110 but also on the front surface of the substrate 110, the surface of the substrate 110 may be formed due to unstable coupling existing near the front and rear surfaces of the substrate 110. The amount of charge lost in the vicinity is reduced, so that the efficiency of the solar cell 1 is improved.

In addition, since the electric field parts 122 and 171 containing high concentrations of impurities of the same conductivity type as the substrate 110 are located not only on the rear surface of the substrate 110 but also on the front surface of the substrate 110. Hole movement to the back is obstructed. As a result, the electrons and holes are recombined and extinguished in the rear and front surfaces of the substrate 110, thereby reducing the efficiency of the solar cell 1.

A plurality of such solar cells 1 may be formed in one module, and the plurality of solar cells 1 may be electrically connected to each other in series through an interconnector (or a ribbon) or may be connected in parallel.

When connected in series, it is possible to increase the output voltage output from one solar cell module formed of a plurality of solar cells (1), and when connected in parallel, it is possible to increase the output current output from one solar cell module. .

3 to 8 below illustrate the arrangement of the first electrode formed on the back side of the emitter portion of the substrate and the second electrode formed on the back side of the rear electric field portion, according to an example of the present invention. The rear electric field is not shown, and only the first electrode and the second electrode are shown on the rear surface of the substrate. In addition, although the emitter portion and the rear electric field portion are not shown and explanation is omitted, the arrangement of the emitter portion and the rear electric field portion is formed substantially similarly to the arrangement of the first electrode and the second electrode.

3 and 4 illustrate the first example of the arrangement of the first electrode 141 and the second electrode 142 formed on the rear surface of the substrate 110 in the solar cell according to the embodiment of FIG. 1 in more detail. It is for the purpose.

As shown in FIG. 3, in the solar cell according to the present invention, at least some of each of the first electrode 141 and the second electrode 142 formed on the rear surface of the substrate 110 may have a vertical side or a horizontal side of the substrate 110. It is formed not parallel to. In other words, when the substrate 110 is cut in the vertical direction or the horizontal direction along the crystal direction of the single crystal silicon, as described above, the longitudinal side and the horizontal side of the substrate 110 coincide with the crystal direction of the substrate 110. At least a portion of the first electrode 141 and the second electrode 142 are formed in the crystal direction and the diagonal direction of the single crystal silicon substrate 110.

As such, the length direction of the first electrode and the second electrode portion which are not parallel to the longitudinal side or the horizontal side of the substrate 110 may be greater than 0 ° and less than 90 ° with respect to the horizontal or vertical side of the substrate 110. For example, it may be formed within an angle range of more than 90 ° and less than 180 °, more than 180 ° and less than 270 °, or more than 270 ° and less than 360 °.

As such, the arrangement of at least a portion of the first electrode 141 and the second electrode 142 may be formed in the oblique direction with the vertical side and the horizontal side, or in the crystal direction and the diagonal direction of the single crystal silicon substrate 110. This is to prevent a phenomenon in which cracks may occur in the substrate 110 during the manufacturing process.

In more detail, during the manufacturing process of the solar cell, the temperature rises from 700 ° C. to 800 ° C. to 1000 ° C. or more. As such, when the temperature rises to a high temperature, the first electrode 141 and the second electrode 142 formed on the rear surface of the substrate 110 and the substrate 110 undergo thermal expansion.

When thermal expansion is performed as described above, the substrate 110 undergoes thermal expansion in the crystal direction, that is, the longitudinal direction and the horizontal direction, and the first electrode 141 and the second electrode 142 undergo thermal expansion in the longitudinal direction.

However, since the thermal expansion coefficients of the first electrode 141 and the second electrode 142 including the metallic material are greater than the thermal expansion coefficient of the substrate 110 including silicon, the substrate 110 may have the first electrode 141. ) And a greater force in the longitudinal direction of the second electrode 142.

Here, when the arrangement direction of the first electrode 141 and the second electrode 142 is formed in the longitudinal direction and the transverse direction, the crystal direction of the substrate 110 and the arrangement direction of the electrodes coincide with each other. During the manufacturing process, a force greater than the force due to the intrinsic thermal expansion coefficient of the substrate 110 is received in the crystallization direction of the substrate 110, so that a crack is generated in the substrate 110.

However, as in the present invention, an arrangement direction of at least a portion of the first electrode 141 and the second electrode 142 is formed in the crystallization direction of the substrate 110, that is, the longitudinal side or the horizontal side of the substrate 110 and the diagonal direction. In this case, the crystal direction of the substrate 110 and the arrangement direction of the first and second electrodes 141 and 142 are different from each other, so that a crack may be prevented by dispersing a force that may be exerted in the crystal direction of the substrate 110. will be.

The arrangement of the first electrode 141 and the second electrode 142 as described above will be described in more detail with reference to the substrate 110.

First, the substrate 110 includes the first corner E1 to the fourth corner E4 in order as shown, wherein the second corner E2 and the third corner E3 are located in diagonal directions with each other. The vertical edge extending from the first edge E1 to the second edge E2 is the first longitudinal edge LV1, and the vertical edge extending from the third edge E3 to the fourth edge E4 is the second vertical edge LV2. , The horizontal edge extending from the first edge E1 to the third edge E3 is defined as the second horizontal edge LH2, and the horizontal edge extending from the second edge E2 to the fourth edge E4 is defined as the second horizontal edge LH2. do.

Here, the first electrode 141 may include a first A electrode connecting portion BA1 and a plurality of first A electrode lines FA1.

Here, the first A electrode connection part BA1 may be formed in parallel to the horizontal side or the vertical side of the substrate 110. For example, the first A electrode connecting portion BA1 is formed in a direction parallel to the first horizontal edge LH1 from the third edge E3 to the first edge E1, and is parallel to the first vertical edge LV1. The first edge E1 to the second edge E2 may be formed adjacent to each other.

The plurality of first A electrode lines FA1 may extend from the first A electrode connection part BA1 and may not be parallel to the vertical side or the horizontal side of the substrate 110. For example, the plurality of first A electrode lines FA1 may be physically and electrically connected to the first A electrode connection part BA1, and may be diagonally formed from the first A electrode connection part BA1 in a diagonal direction, that is, a fourth edge E4 direction. Can be extended. In this way, the charges collected from the first A electrode line FA1, that is, the holes, may be moved to the first A electrode connection BA1 through the first A electrode line FA1. The plurality of first A electrode lines FA1 may be electrically connected to each other through the first A electrode connection part BA1.

In addition, the second electrode 142 may include a second A electrode connection part BA2 and a plurality of second A electrode lines FA2.

Here, the 2A electrode connection part BA2 may be formed to be parallel to the horizontal side or the vertical side opposite to the first A electrode connection part BA1 on the substrate 110, and as illustrated, for example, the 2A electrode connection part BA2. BA2 is formed in the direction parallel to the second longitudinal side LV2 from the third corner E3 to the fourth corner E4, and is adjacent to the second horizontal side LH2 in the direction parallel to the fourth corner E4. ) To the second edge E2.

The plurality of second A electrode lines FA2 may extend from the second A electrode connection part BA2 and may not be parallel to the vertical side or the horizontal side of the substrate 110. As a specific example, the plurality of second A electrode lines FA2 may be physically and electrically connected to the second A electrode connection part BA2, and may be diagonally formed from the second A electrode connection part BA2, ie, in a diagonal direction, ie, in a diagonal direction. It can be extended to.

As such, the plurality of second A electrode lines FA2 may be electrically connected to each other through the second A electrode connection part BA2.

In this way, the charges collected from the second A electrode line FA2, that is, electrons, may be transferred to the second A electrode connection BA2 through the second A electrode line FA2.

As described above, the plurality of first A electrode lines FA1 and the plurality of second A electrode lines FA2 of the first electrode 141 and the second electrode 142 are parallel to the crystallographic direction of the substrate 110. By forming diagonal lines on the sides LV1 and LV2 and the first and second horizontal sides LH1 and LH2, even if high heat occurs during the manufacturing process of the solar cell, the plurality of first A electrode lines FA1 and the plurality of second A electrodes Even if the thermal expansion in the longitudinal direction of the line (FA2) it is possible to prevent the crack (Crack) by dispersing the force that can be exerted in the crystal direction of the substrate 110 as much as possible.

Here, the plurality of first A electrode lines FA1 and the plurality of second A electrode lines FA2 may be alternately arranged side by side.

Here, the first electrode 141 and the second electrode 142 illustrated in FIG. 3 will be described in detail with reference to FIG. 4. 4 is an enlarged view of a portion A of FIG. 3.

As illustrated in FIG. 4, the widths WBA1 and WBA2 of the first A electrode connection part BA1 and the second A electrode connection part BA2 may be substantially the same. An interconnector for electrically connecting the plurality of solar cells to each other may be disposed on the rear surface of the first AA connection part BA1 of the first electrode 141 and the second AA connection part BA2 of the second electrode 142. It is.

More specifically, when the plurality of solar cells are connected in series, the plurality of solar cells may be electrically connected to each other through interconnectors formed in the direction parallel to the first longitudinal side LV1 at the first A electrode connection part BA1. The parts formed in the direction parallel to the second vertical side LV2 in the 2A electrode connection part BA2 may be electrically connected to each other through an interconnector.

In addition, the widths WFA1 and WFA2 of each of the plurality of first A electrode lines FA1 and the plurality of second A electrode lines FA2 may include a width WBA1 of each of the first A electrode connection part BA1 and the second A electrode connection part BA2. Although not shown, each of the plurality of first A electrode lines FA1 and the plurality of second A electrode lines FA2 may have a thickness of the first A electrode connection part BA1 and the second A electrode connection part BA2. ) May be less than each thickness.

In this way, the unit volume of each of the plurality of first A electrode lines FA1 and the plurality of second A electrode lines FA2 may be smaller than the unit volume of each of the first A electrode connection part BA1 and the second A electrode connection part BA2. The thermal expansion rate of each of the plurality of first A electrode lines FA1 and the plurality of second A electrode lines FA2 may be smaller than that of each of the first A electrode connection part BA1 and the second A electrode connection part BA2. It is.

Therefore, even if the plurality of first A electrode lines FA1 and the plurality of second A electrode lines FA2 thermally expand, the force applied in the crystal direction of the substrate 110 can be made relatively smaller on the surface of the substrate 110. It is. In addition, the widths WFA1 and WFA2 of each of the plurality of first A electrode lines FA1 and the plurality of second A electrode lines FA2 may be relatively smaller, thereby increasing the number of the plurality of first A electrode lines FA1. And the plurality of second A electrode lines FA2 are alternately arranged, whereby the photoelectric efficiency of the solar cell can be further improved.

In addition, the widths WBA1 and WBA2 of each of the first A electrode connection part BA1 and the second A electrode connection part BA2 are defined by the widths of each of the plurality of first A electrode lines FA1 and the plurality of second A electrode lines FA2. By making it larger than the WFA1 and WFA2, the majors or electrons collected in each of the plurality of first A electrode lines FA1 and the plurality of second A electrode lines FA2 are transferred to the first A electrode connection part BA1 and the second A electrode connection part BA2. ), The resistance at the first A electrode connection part BA1 and the second A electrode connection part BA2 is relatively smaller than that of the plurality of first A electrode lines FA1 and the plurality of second A electrode lines FA2. By doing so, the movement of electrons and majors can be made more smooth.

The width WBA1 of each of the first A electrode connection part BA1 and the second A electrode connection part BA2 compared to the widths WFA1 and WFA2 of each of the plurality of first A electrode lines FA1 and the plurality of second A electrode lines FA2, respectively. , WBA2) ratio may be 1: 5 to 40, for example. That is, for example, when the width WFA1 of the first A electrode line FA1 is 50 μm, the width WBA1 of the first A electrode connection part BA1 may be selected to be in a range of 250 μm or more and 2 mm or less.

Here, the width ratio greater than 1: 5 is such that the force that can be applied to the substrate 110 by thermal expansion of each of the plurality of first A electrode lines FA1 and the plurality of second A electrode lines FA2 is minimized. The width ratio is greater than 1:40 so that the resistance that can be exerted when the holes and electrons collected in each of the plurality of first A electrode lines FA1 and the plurality of second A electrode lines FA2 are moved is minimized. To do this.

In FIG. 4, the width WFA1 of the plurality of first A electrode lines FA1 is the same as the width WFA2 of the plurality of second A electrode lines FA2, but the plurality of first A electrode lines are different from each other. The width WFA1 of FA1 may be larger than the width WFA2 of the plurality of second A electrode lines FA2. 1 and 2, when the substrate 110 is a semiconductor substrate 110 made of n-type conductivity type silicon, holes move toward the emitter portion 121, and electrons form a rear electric field portion 122. To the side. At this time, the movement distance of the holes which are the minority carriers collected by the first electrode 141 by making the width WFA1 of the plurality of first A electrode lines FA1 larger than the width WFA2 of the plurality of second A electrode lines FA2. It can be shortened to further improve the photoelectric efficiency of the solar cell.

For example, the ratio of the width WFA2 of the plurality of first A electrode lines FA1 to the width WFA2 of the plurality of second A electrode lines FA2 may be 1: 1.5 to 2.5.

Here, the ratio is 1: 1.5 or more in order to minimize the movement distance of the hole in consideration of the moving speed of the electrons and holes, and the ratio is 1: 2.5 or less so that the electrons are the second A electrode line. This is to provide an appropriate width to the second A electrode line FA2 in order to minimize the resistance that may be exerted on the electrons when collected by FA2 and flows to the second A electrode connection BA2. Accordingly, the photoelectric efficiency of the solar cell can be optimized.

5 and 6 will be described in more detail a second example of the arrangement of the first electrode 141 and the second electrode 142 formed on the rear surface of the substrate 110 in the solar cell according to the embodiment of FIG. It is for the purpose.

As shown in FIG. 5, the first electrode 141 may further include a first B electrode connection BB1 and a first B electrode line FB1 in addition to the first A electrode connection BA1 and the first A electrode line FA1. It may be formed.

Here, as shown in FIG. 5, the first A electrode connection part BA1 is the same as that of FIG. 3, and the length of the first A electrode line FA1 is relative to the length of the first A electrode line FA1 shown in FIG. 3. It may be formed shorter, the width or thickness of the remaining first A electrode line FA1 may be the same as mentioned in FIG.

The first B electrode connection part BB1 may extend in a diagonal direction from an end of the first A electrode connection part BA1 formed at the edge of the substrate 110. As a specific example, the first B electrode connecting portion BB1 extends from the first A electrode connecting portion BA1 formed at the second corner E2 toward the third corner E3, and the first B electrode at the second corner E2. The connection part BB1 is physically and electrically connected to the first A electrode connection part BA1.

In addition, the plurality of first B electrode lines FB1 may extend from the first B electrode connection part BB1 so as not to be parallel to the longitudinal side or the horizontal side of the substrate 110. As a specific example, the plurality of first B electrode lines FB1 may be physically and electrically connected to the first B electrode connection part BB1, and may be longitudinally formed from the first B electrode connection part BB1, that is, the first edge E1. And extend in the direction of the fourth corner E4 positioned in the diagonal direction. As described above, the plurality of first B electrode lines FB1 are formed in diagonal directions of the second horizontal side LH2 and the second vertical side LV2. The plurality of first B electrode lines FB1 may be alternately arranged in parallel with the plurality of second A electrode lines FA2.

In addition, the second electrode 142 may further include a second B electrode connection part BB2 and a second B electrode line FB2 in addition to the second A electrode connection part BA2 and the second A electrode line FA2.

Here, the second A electrode connection part BA2 is the same as that of FIG. 3, and the length of the second A electrode line FA2 is formed to be relatively shorter than the length of the second A electrode line FA2 shown in FIG. 3. The width or thickness of the 2A electrode line FA2 may be the same as mentioned in FIG. 3.

Here, the second B electrode connection part BB2 may be formed extending from the opposite diagonal edge of the end of the first B electrode connection part BB1 toward the end of the first B electrode connection part. In detail, the second B electrode connection part BB2 extends from the second A electrode connection part BA2 formed at the third edge E3 in the direction of the second corner E2, and the second B electrode connection part is formed at the third edge part E3. BB2 is physically and electrically connected to the second A electrode connection part BA2. In addition, the plurality of second B electrode lines FB2 are physically and electrically connected to the second B electrode connecting portion BB2 and are positioned in a longitudinal direction from the second B electrode connecting portion BB2, that is, in a diagonal direction with the fourth corner E4. Extends in the direction of the first edge E1.

As described above, the plurality of second B electrode lines FB2 may extend from the second B electrode connection part BB2 so as not to be parallel to the longitudinal side or the horizontal side of the substrate 110. As a specific example, the plurality of second B electrode lines FB2 may be formed in diagonal directions between the first horizontal side LH1 and the first vertical side LV1. Such a plurality of second B electrode lines FB2 are alternately arranged in parallel with the plurality of first A electrode lines FA1.

As such, the arrangement form of the first electrode 141 and the second electrode 142 illustrated in FIG. 5 may be arranged in a direction in which the plurality of electrode lines extending from each electrode connection portion may be arranged in comparison with the arrangement illustrated in FIG. 3. More diversified

As described above, the direction in which the plurality of electrode lines are arranged to be more diversified makes it possible to further disperse the force that may be exerted in the crystal direction of the substrate 110, thereby preventing cracks more effectively. In addition, the length of each of the plurality of electrode lines having a relatively high electrical resistance is further reduced to reduce the movement path of electrons and holes in each of the plurality of electrode lines. You can make the movement smoother.

Here, the first electrode 141 and the second electrode 142 illustrated in FIG. 5 will be described in detail with reference to FIG. 6. FIG. 6 is an enlarged view of a portion B in FIG. 5.

As shown in FIG. 6, each of the widths WBB1 and WBB2 of the first B electrode connection part BB1 and the second B electrode connection part BB2 is respectively the first A electrode connection part BA1 and the second A electrode connection part BA2. The widths WBA1 and WBA2 may be equal to each other, and each of the widths WBB1 and WBB2 of the first B electrode connection part BB1 and the second B electrode connection part BB2 may have a plurality of first B electrode lines FB1 and a plurality of widths. It may be larger than the widths WFB1 and WFB2 of each of the second B electrode lines FB2.

The length of the plurality of first A electrode lines FA1 and the second A electrode lines FA2 having a relatively high resistance may be shorter than that of FIG. It is possible to further shorten the movement path of electrons and holes in the 2A electrode line FA2, and the first resistance BB1 and the second resistance BB2 having a relatively low resistance are diagonally formed at the edges of the substrate 110. Further formed in the direction, and further formed such that the plurality of first and second electrode lines FB1 and FB2 having a relatively high resistance extend from the first B electrode connection part BB1 and the second B electrode connection part BB2, respectively. As a result, the distance between electrons and holes in the first and second electrode lines FB1 and FB2 having a relatively high resistance is further shortened, and the first and second electrode connection parts BB1 and 2B having a low resistance are further shortened. More electrons and holes collected through the electrode connection (BB2) It can be moved to desired it is possible to further improve the photoelectric efficiency of the solar cell.

6, the widths WFA1, WFA2, WFB1, and WFB2 of the plurality of first A electrode lines FA1, the second A electrode lines FA2, the first B electrode lines FB1, and the second B electrode lines FB2 are illustrated in FIG. 6. Although illustrated as being identical to each other, the width WFA1 of the plurality of first A electrode lines FA1 may be greater than the width WFB2 of the plurality of second B electrode lines FB2, and the plurality of first B electrode lines ( The width WFB1 of FB1 may be greater than the width WFA2 of the plurality of second A electrode lines FA2.

By doing in this way, the movement distance of the hole which is a minority carrier collected by the 1st electrode 141 can be shortened, and the photoelectric efficiency of a solar cell can be improved further.

7 and 8 illustrate a third example of the arrangement of the first electrode 141 and the second electrode 142 formed on the rear surface of the substrate 110 in the solar cell according to the embodiment of FIG. 1 in more detail. It is for the purpose.

The plurality of first electrode lines and the second electrode lines may be formed at different angles according to regions on the substrate.

In detail, as illustrated in FIG. 7, the first electrode 141 may include a first electrode in addition to the first electrode connection part BA1 and the first electrode line FA1, the first electrode electrode connection part BB1, and the first electrode electrode line FB1. The 1C electrode connection part BC1 and the first C electrode line FC1 may be further included.

Here, as shown in FIG. 7, the first A electrode connecting portion BA1 and the first B electrode connecting portion BB1 are the same as those of FIG. 5, and are obliquely aligned from the first A electrode connecting portion BA1 parallel to the first longitudinal side LV1. The plurality of first A electrode lines FA1 extending to the plurality of second B electrode lines FB2 extending vertically from the second B electrode connecting portion BB2 in parallel with each other may be the same as in FIG. 5. The plurality of first A electrode lines FA1 extending from the first A electrode connection part BA1 parallel to the first horizontal side LH1 are different from the first A electrode connection part BA1 as shown in FIG. 7, unlike FIG. 5. The first B electrode connection part BB1 or the second B electrode connection part BB2 may be formed to extend in an oblique direction.

The 1C electrode connection part BC1 may extend from the middle of the first B electrode connection part BB1 in the corner direction of the second A electrode connection part BA2. In detail, as illustrated in FIG. 7, the first C electrode connection part BC1 extends from the middle portion of the first B electrode connection part BB1 in the direction of the fourth corner E4 in the vertical direction, and the first C electrode connection part BC1. The width WBC1 of) and the width WBB1 of the first B electrode connection portion BB1 may be formed to be the same as illustrated.

The plurality of first C electrode lines FC1 may extend in the vertical direction from the first C electrode connection part BC1 and may be formed in an oblique direction on the second horizontal edge LH2 on which the second A electrode connection part is formed. The electrode lines FC1 are arranged side by side alternately with the plurality of second A electrode lines FA2.

 As shown in FIG. 7, the second electrode 142 also has a second C electrode in addition to the second AA connection part BA2 and the second A electrode line FA2, the second B electrode connection part BB2, and the second B electrode line FB2. The connection part BC2 and the second C electrode line FC2 may be further included.

Here, as shown in FIG. 7, the second A electrode connecting portion BA2 and the second B electrode connecting portion BB2 are the same as those of FIG. 5, and are obliquely aligned from the second A electrode connecting portion BA2 parallel to the second longitudinal side LV2. The plurality of second A electrode lines FA2 extending in parallel to the plurality of first B electrode lines FB1 extending vertically from the first B electrode connecting portion BB1 in parallel with each other may be the same as in FIG. 5. The second A electrode lines FA2 extending from the second A electrode connection part BA2 parallel to the first horizontal side LH1 are different from the second A electrode connection part BA2 as shown in FIG. 7, unlike FIG. 5. The first B electrode connection part BB1 or the second B electrode connection part BB2 may be formed to extend in an oblique direction.

The second C electrode connection part BC2 may be formed extending from the middle portion of the second B electrode connection part BB2 in the corner direction of the first A electrode connection part. In detail, the second C electrode connection part BC2 extends from the middle portion of the second B electrode connection part BB2 in the direction of the first edge E1 in the vertical direction, and the width WBC2 and the second B of the second C electrode connection part BC2. Widths WBB2 of the electrode connection part BB2 may be formed to be the same as shown in the figure.

The plurality of second C electrode lines FC2 may extend in the vertical direction from the second C electrode connection part BC2 and may be formed in an oblique direction on the first horizontal edge LH1 on which the first A electrode connection part is formed. The electrode lines FC2 are alternately arranged in parallel with the plurality of first A electrode lines FA1.

As such, the arrangement of the first electrode 141 and the second electrode 142 illustrated in FIG. 7 may be compared with that of each of the plurality of electrode lines extending from each electrode connection as compared with the arrangement illustrated in FIG. 3 or 5. The arrangement direction is very diverse.

In detail, as illustrated in FIG. 7, the extending direction of the plurality of first C electrode lines FC1 is the plurality of first A electrode lines FA1 extending from the first electrode connection part BA1 formed on the first vertical side LV1. ) And the extending direction of the plurality of first B electrode lines FB1, and the extending direction FC2 of the plurality of second C electrode lines extends from the second electrode connection part BA2 formed on the second vertical side LV2. One of the plurality of second A electrode lines FA2 and the plurality of second B electrode lines FB2 may be formed to be different from each other.

As described above, the direction in which the plurality of electrode lines are arranged to be more diversified makes it possible to further disperse the force that may be exerted in the crystal direction of the substrate 110, thereby preventing cracks more effectively. In addition, the length of each of the plurality of electrode lines having a relatively high electrical resistance is further reduced to reduce the movement path of electrons and holes in each of the plurality of electrode lines. You can make the movement smoother.

Here, the first electrode 141 and the second electrode 142 illustrated in FIG. 7 will be described in detail with reference to FIG. 8. FIG. 8 is an enlarged view of a portion C in FIG. 7.

As shown in FIG. 8, each of the widths WBC1 and WBC2 of the first C electrode connection part BC1 and the second C electrode connection part BC2 may correspond to each of the first B electrode connection part BB1 and the second B electrode connection part BB2. The widths WBB1 and WBB2 may be equal to each other, and each of the widths WBC1 and WBC2 of the first C electrode connection part BC1 and the second C electrode connection part BC2 may have a plurality of first C electrode lines FC1 and a plurality of widths. The second C electrode line FC2 may be formed larger than the widths WFC1 and WFC2, respectively.

As such, the relatively low resistance of the first C electrode connection part BC1 and the second C electrode connection part BC2 in the diagonal direction from the central portion of the substrate 110 to the first edge E1 or the fourth edge E4. Further, by further forming a plurality of relatively high resistance of the first C electrode line FC1 and the second C electrode line FC2 so as to extend from the first C electrode connection part BC1 and the second C electrode connection part BC2, respectively, By further shortening the moving distance between electrons and holes, the collected electrons and holes can be moved more smoothly, thereby further improving the photoelectric efficiency of the solar cell.

In addition, although the widths WFC1 and WFA2 of the plurality of first C electrode lines FC1 and the second A electrode line FA2 are the same as each other, in FIG. 8, the widths of the plurality of first C electrode lines FC1 are different from each other. WFC1 may be greater than the width WFA2 of the plurality of second A electrode lines FA2, and the widths WFA1 and WFC2 of the plurality of first A electrode lines FA1 and the second C electrode line FC2 are equal to each other. Alternatively, the width WFC1 of the plurality of first C electrode lines FC1 may be greater than the width WFC2 of the plurality of second C electrode lines FC2.

By doing in this way, the movement distance of the hole which is a minority carrier collected by the 1st electrode 141 can be shortened, and the photoelectric efficiency of a solar cell can be improved further.

In the first embodiment thus far, the case where the substrate 110 is the single crystal silicon substrate 110 and the emitter portion and the rear electric field portion are formed through the diffusion process has been described as an example. The case where the amorphous silicon layer is formed by lamination unlike the case where the tab portion and the rear electric field portion are formed of crystalline silicon will be described as an example.

However, in the second embodiment as described above, the arrangement of the first electrode 141 and the second electrode 142 formed on the rear surface of the substrate 110 may be applied as is. Therefore, although a separate description is omitted, the arrangement of the first electrode 141 and the second electrode 142 described above may also be applied to the second embodiment in the same manner as described with reference to FIGS. 3 to 8.

9 and 10 are diagrams for explaining in detail the solar cell according to the second embodiment of the present invention.

9 is a partial perspective view of a solar cell according to a second exemplary embodiment of the present invention, and FIG. 10 is a cross-sectional view of the solar cell shown in FIG. 9 taken along the line X-X.

9 and 10, the solar cell 2 according to the second embodiment of the present invention, like the solar cell 1 according to the first embodiment of the present invention, the substrate 110, the front surface protection Part 191, antireflection 130, back protection 192, a plurality of emitters 121, a plurality of back surface fields (BSF) 172, and first electrode 141. And a second electrode 142 and perform the same function as the solar cell 1 according to the first embodiment. In addition, hereinafter, the solar cell 2 according to the second embodiment will be mainly described that the difference from the solar cell 1 according to the first embodiment. Therefore, the parts which are not described separately are treated as the same as the solar cell 1 according to the first embodiment.

The substrate 110 may be a semiconductor substrate made of silicon of a first conductivity type, for example, an n-type conductivity, like the first embodiment, and may be crystalline silicon such as single crystal silicon, and its function may be the same as that of the first embodiment. same.

Unlike the solar cell 1 according to the first embodiment, the front protection part 191 formed on the substrate 110 may be formed by depositing intrinsic amorphous silicon (a-Si). The function is the same as that of the substrate 110 of the first embodiment.

The back protection part 192 located directly on the back of the substrate 110 may be formed by depositing amorphous silicon or the like, similar to the front protection part 191, and its function may be formed by the back protection part 192 of the first embodiment. Is the same as

Unlike the first embodiment, the plurality of rear electric field parts 172 are disposed on the rear protection part 192, and are an amorphous region in which impurities of the same conductivity type as the substrate 110 are doped at a higher concentration than the substrate 110. The amorphous semiconductor layer, such as silicon (a-Si), may be formed by deposition, but its function is the same as that of the plurality of backside electric fields 172 of the first embodiment.

Unlike the first embodiment, the plurality of emitters 121 are disposed on the rear protection part 192, and are spaced apart from the plurality of rear electric fields 172 on the rear of the substrate 110, and the plurality of rear electric fields. It is formed in parallel with 172.

As shown in FIGS. 9 and 10, the rear electric field part 172 and the emitter part 121 are alternately positioned on the substrate 110.

Each emitter portion 121 has a second conductivity type opposite to the conductivity type of the substrate 110, for example, a p-type conductivity type, and is formed of a semiconductor different from the substrate 110, for example, amorphous silicon. consist of. Thus, the emitter portion 121 forms a hetero junction as well as the p-n junction with the substrate 110, but its function is the same as that of the emitter portion 121 of the first embodiment.

As described above, in the second exemplary embodiment, the backside protection part 192 is positioned between the plurality of emitter parts 121 and the plurality of backside electric field parts 172 and the substrate 110, and is an intrinsic semiconductor having little or no impurities. Due to the backside protection 192 of the material (intrinsic a-Si), a plurality of emitters 121 and a plurality of backside electric fields 172 are placed directly on the substrate 110 made of crystalline semiconductor material. When the emitter portion 121 and the plurality of rear electric field portions 172 are formed, the crystallization phenomenon is reduced. As a result, the characteristics of the plurality of emitter portions 121 and the plurality of rear electric field portions 172 positioned on the amorphous silicon are improved.

In addition, unlike the solar cell 1 according to the first embodiment, in the solar cell 2 according to the second embodiment, the front protection unit 191, the rear protection unit 192, the emitter unit 121, and the rear surface of the solar cell 2 according to the second embodiment. The step portion 172 may be formed by laminating an amorphous silicon material on the substrate 110 of crystalline silicon.

The solar cell 2 according to the second embodiment has a high openness due to the heterojunction between amorphous silicon and the crystalline silicon substrate 110 having a larger energy band gap than the solar cell 1 according to the first embodiment. Output voltage (Voc) can be implemented, and the process temperature is relatively low, which can reduce the production cost.

As in the first embodiment, the first electrode 141 is positioned on the plurality of emitter portions 121, extends along the plurality of emitter portions 121, and is electrically connected to the plurality of emitter portions 121. have.

The second electrode 142 is positioned on the plurality of rear electric field units 172, extends along the plurality of rear electric field units 172, and is electrically and physically connected to the plurality of rear electric field units 172. .

As such, the form in which the first electrode 141 and the second electrode 142 according to the second embodiment are arranged may be formed in the same manner as FIGS. 3 to 8 of the first embodiment.

Accordingly, in the solar cell 2 according to the second embodiment, the arrangement direction of at least a portion of the first electrode 141 and the second electrode 142 is determined in the crystal direction of the substrate, that is, in the longitudinal direction or the horizontal side of the substrate and the diagonal direction. As a result, the crystal direction of the substrate 110 and the arrangement direction of the first and second electrodes 141 and 142 are different from each other to disperse the force that may be exerted in the crystal direction of the substrate, thereby preventing cracks that may occur in the substrate. can do.

The above description is merely illustrative of the technical idea of the present invention, and various modifications, changes, and substitutions may be made by those skilled in the art without departing from the essential characteristics of the present invention. will be. Accordingly, the embodiments disclosed in the present invention and the accompanying drawings are not intended to limit the technical spirit of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by the embodiments and the accompanying drawings. . The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

Claims (19)

A first conductive type substrate having a rectangular shape having a horizontal side in a horizontal direction and a vertical side in a vertical direction,
At least one emitter portion connected to the substrate and having a second conductivity type opposite to the first conductivity type,
A first electrode connected to the at least one emitter portion, and
A second electrode electrically connected to the substrate;
At least some of each of the first electrode and the second electrode is not formed parallel to the longitudinal side or the horizontal side of the substrate. The method of claim 1,
At least a portion of each of the first electrode and the second electrode has a length direction of less than 0 ° and less than 90 °, more than 90 ° and less than 180 °, more than 180 ° and less than 270 ° with respect to a horizontal surface or a vertical side of the substrate, Solar cell, characterized in that formed within an angle range of more than 270 ° and less than 360 °. The method of claim 1,
The at least part of each of the first electrode and the second electrode is formed in parallel with each other, the solar cell. The method of claim 1,
The at least part of each of the first electrode and the second electrode is formed alternately with each other. The method of claim 1,
The first electrode is
The first A electrode connecting portion formed to be parallel to the horizontal side or the vertical side of the substrate; And
And a plurality of first A electrode lines extending from the first A electrode connecting portion so as not to be parallel to a vertical side or a horizontal side of the substrate.
The second electrode is
A second A electrode connecting portion formed to be parallel to the horizontal side or the vertical side opposite to the first A electrode connecting portion in the substrate; And
And a plurality of second AA electrode lines extending from the second A electrode connection portion so as not to be parallel to the longitudinal side or the horizontal side of the substrate. The method of claim 1,
The first A electrode connecting portion connects the plurality of first A electrode lines to each other,
And the second A electrode connecting portion connects the plurality of second A electrode lines to each other. The method of claim 2,
The solar cell of claim 1, wherein the width of the first A electrode connection portion and the second A electrode connection portion are substantially the same. The method of claim 2,
The width of each of the plurality of first A electrode lines and the plurality of second A electrode lines is smaller than the width of each of the first A electrode connection portion and the second A electrode connection portion. The method of claim 2,
The width of the plurality of first A electrode line is larger than the width of the plurality of second A electrode line. The method of claim 1,
The first electrode is
A first electrode connecting portion extending in a diagonal direction from an end of the first electrode connecting portion formed at an edge of the substrate; And
And a plurality of first B electrode lines extending from the first B electrode connecting portion so as not to be parallel to the vertical or horizontal sides of the substrate.
The second electrode is
A second B electrode connecting portion extending in an end direction of the first B electrode connecting portion from an opposite diagonal edge of the end of the first B electrode connecting portion; And
And a plurality of second B electrode lines extending from the second B electrode connection portion so as not to be parallel to the longitudinal side or the horizontal side of the substrate. The method of claim 7, wherein
The plurality of first A electrode lines and the plurality of second B electrode lines are alternately arranged side by side,
And the plurality of 2A electrode lines and the plurality of 1B electrode lines are alternately arranged side by side. The method of claim 7, wherein
A width of each of the first and second electrode connection portions of the first and second electrode electrodes is greater than the width of each of the plurality of first electrode lines and the plurality of first electrode lines. The method of claim 7, wherein
The width of the plurality of first A electrode line is larger than the width of the plurality of second B electrode line. The method of claim 7, wherein
And a width of the plurality of first B electrode lines is greater than a width of the plurality of second A electrode lines. The method of claim 1,
And the plurality of first and second electrode lines are formed at different angles according to regions on the substrate. The method of claim 7, wherein
The first electrode is
A plurality of first C electrodes extending in a diagonal direction of a horizontal side in which the first C electrode connecting portion extending from the middle portion of the first B electrode connecting portion in the corner direction of the second A electrode connecting portion and the second A electrode connecting portion formed from the first C electrode connecting portion; Including more lines,
The second electrode is
A plurality of first C electrodes extending in a diagonal direction of a horizontal side in which the second C electrode connecting portion extending from the middle portion of the second B electrode connecting portion in the corner direction of the first A electrode connecting portion and the first A electrode connecting portion formed from the second C electrode connecting portion; The solar cell further comprises a line. The method of claim 7, wherein
The extending direction of the plurality of first C electrode lines is different from the extending direction of some of the plurality of first A electrode lines and the plurality of first B electrode lines,
The extending direction of the plurality of second C electrode lines is different from the extending direction of some of the plurality of second A electrode lines and the plurality of second B electrode lines. A single crystal silicon substrate of a first conductivity type,
At least one emitter portion connected to the substrate and having a second conductivity type opposite to the first conductivity type,
A first electrode connected to the at least one emitter portion, and
A second electrode electrically connected to the substrate;
At least a portion of each of the first electrode and the second electrode is a solar cell, characterized in that formed in the diagonal direction and the crystal direction of the single crystal silicon included in the substrate. The method of claim 17,
The first electrode may further include a first electrode connection part formed in a direction parallel to a crystal direction of single crystal silicon included in the substrate to connect each of the plurality of first electrode lines.
The second electrode may further include a second electrode connection part formed in a direction parallel to the crystal direction of the single crystal silicon on the substrate, the second electrode connection part connecting each of the plurality of second electrode lines. Solar cell.

Images