WO2021200286A1

WO2021200286A1 - Solar cell and method for manufacturing solar cell

Info

Publication number: WO2021200286A1
Application number: PCT/JP2021/011481
Authority: WO
Inventors: 哲也会田; 俊介功刀
Original assignee: 積水化学工業株式会社
Priority date: 2020-03-31
Filing date: 2021-03-19
Publication date: 2021-10-07
Also published as: JPWO2021200286A1

Abstract

This solar cell (100) is provided with: a plurality of first conductive layers (20) formed on an upper surface of an insulating base material (10) and arranged at an interval (20G); a power generation layer (30) disposed so as to cover a surface of the plurality of first conductive layers (20); and a plurality of second conductive layers (40) formed on an upper surface side of the power generation layer (30) and each disposed with an overlapping portion (42) overlapping an adjacent one of the first conductive layers (20) in a plane direction. The solar cell (100) is further provided with a through-hole row (50) formed in the power generation layer (30) and comprising a plurality of through-holes (51) formed at an interval in a region corresponding to the overlapping portion (42). The plurality of second conductive layers (40) are successively electrically connected via the through-hole row (50) corresponding to a plurality of adjacent first conductive layers (20) among the plurality of first conductive layers (20).

Description

Solar cells and solar cell manufacturing methods

The present invention relates to solar cells and methods for manufacturing solar cells.
The present application claims priority based on Japanese Patent Application No. 2020-065358 filed in Japan on March 31, 2020, the contents of which are incorporated herein by reference.

In recent years, as a clean power generation source, light energy can be directly and immediately converted into electric power, and as an energy source that does not emit carbon dioxide, photovoltaic power generation using an electric module such as a solar cell has been attracting attention.

Crystalline silicon-based solar cells are widely used as solar cells. However, crystalline silicon-based solar cells have problems such as stable supply of high-purity silicon as a raw material and high cost.
On the other hand, a solid-state junction type photoelectric conversion element (for example, a dye-sensitized solar cell (DSC)) is a next-generation solar cell because it can be manufactured relatively easily and the unit price of raw materials is low. It is expected as a battery.

Among them, in recent years, it has been reported that a solid-bonded photoelectric conversion element provided with a power generation layer containing a perovskite compound exhibits high photoelectric conversion efficiency, and is attracting attention as a new photoelectric conversion element (for example, non-patent documents). 1.).
Further, various techniques for improving the performance of the solid-state junction type photoelectric conversion element are disclosed (see, for example, Patent Document 1).

The solid-state junction type photoelectric conversion element (hereinafter referred to as a solar cell) has a structure as shown in FIGS. 14 and 15, for example. 14 and 15 are views showing an example of a schematic configuration of the structure of a conventional solar cell.

As shown in FIGS. 14 and 15, for example, the solar cell 500 has a plurality of first conductors formed on the insulating base material 510 and the surface side (upper surface) A of the insulating base material 510 with an interval of 520 G. The layer 520, the power generation layer 530 arranged so as to cover the surfaces of the plurality of first conductive layers 520, and the plurality of second conductive layers 540 formed on the surface side A of the power generation layer 530 with an interval of 540 G. , Prepared.

Further, in the power generation layer 530, a scribing groove 530H penetrating in the thickness direction is formed to expose the first conductive layer 520, and the scribing groove 530H is filled with a conductive material constituting the second conductive layer 540 to conduct conductivity. The first conductive layer 520 and the second conductive layer 540 are electrically connected to each other by forming the portion 541, and as a result, the power generation layers 30 arranged adjacent to each other are sequentially electrically connected by the conductive portion 541.
Further, in the first conductive layer 520, leader wires (not shown) are connected to the first conductive layer 520F located on one end side F and the first conductive layer 520R located on the other end side R, respectively.

In each power generation layer 530, electrons are generated when sunlight is irradiated, and these electrons move from each power generation layer 530 to the first conductive layer 520, and are sequentially adjacent to the other end side via the conductive portion 541. It moves toward the first conductive layer 520 of R. The holes generated in the power generation layer 530 move to the second conductive layer 540 on the surface side A. As a result, a plurality of power generation layers 530 are connected in series to form an electric module.
Then, the electric energy generated by the solar cell 500 is taken out to the outside through the leader line (not shown).

The scribe groove 530H is formed by irradiating the power generation layer 530 with a laser beam to remove the power generation layer 530 in the power generation layer scribing step when manufacturing the solar cell 500.

In the conventional power generation layer scribing step, for example, a pulse laser is irradiated to form a power generation layer 530 with substantially circular (for example, several tens of μm in diameter) through holes (not shown) overlapping without intervals. By doing so, a continuous scribing groove 530H was formed. Then, the conductive material used for forming the second conductive layer 540 is connected to the first conductive layer 520 through the scribe groove 530H to form the conductive portion 541.

At this time, if the scribe groove 530H does not properly expose the first conductive layer 520, the conductive portion 541 is not connected to the first conductive layer 520, and the conduction between the first conductive layer 520 and the second conductive layer 540 is obtained. I can't.
Further, as shown by reference numerals 520X in FIGS. 14 and 15, when the first conductive layer 520 is removed and the insulating base material 510 is exposed, the conductive portion 541 is no longer connected to the first conductive layer 520. Conduction between the first conductive layer 520 and the second conductive layer 540 cannot be obtained.
Therefore, in the scribe groove 530H, it is required that the surface of the first conductive layer 520 is surely exposed, the conduction by the conductive portion 541 is surely obtained, and the first conductive layer 520 is not damaged.

Japanese Patent Application Laid-Open No. 2017-028027

However, it is difficult in mass production to adjust the laser power while checking the condition of the scribing groove when forming the scribing groove in the power generation layer scribing process.
Therefore, there is a need for a technology that can stably secure continuity even when there are variations in laser beam power (output) and power generation layers.

The present invention has been made in consideration of such circumstances, and provides a solar cell and a method for manufacturing a solar cell capable of ensuring stable conduction between the first conductive layer and the second conductive layer. The purpose is.

In order to solve the above problems, the present invention proposes the following means.
(1) In the first aspect of the present invention, a plurality of first conductive layers arranged at intervals on one surface of an insulating base material and a plurality of first conductive layers arranged so as to cover the surfaces of the first conductive layers. The power generation layer including the photoelectric conversion layer and the plurality of second conductive layers provided on the surface side of the power generation layer at intervals facing each other of the first conductive layers. When viewed from a direction perpendicular to the surface of the power generation layer, a plurality of second conductive layers arranged so as to overlap with the first conductive layer adjacent to the first conductive layer facing each other are provided, and the overlap is provided. A plurality of through holes are arranged in the portion along the surface direction of the power generation layer and penetrate the power generation layer in the thickness direction, and the through holes are boundaries between the power generation layer and the first conductive layer. The plurality of second conductive layers are sequentially electrically connected through the through holes communicating with the first conductive layer adjacent to the first conductive layer facing each other. Is.

According to the solar cell according to the above aspect, the plurality of first conductive layers formed on one surface of the insulating base material and arranged at intervals, and the surfaces of the plurality of the first conductive layers (that is, the first one). The surface of the conductive layer opposite to the insulating base material) is arranged so as to cover the power generation layer including the photoelectric conversion layer, and a plurality of first conductive layers are spaced apart from each other on the surface side of the power generation layer. A plurality of second conductive layers provided with a gap, and an overlapping portion that overlaps with the first conductive layer adjacent to the first conductive layer facing the first conductive layer when viewed from a direction perpendicular to the surface of the power generation layer. A plurality of arranged second conductive layers are provided, and a plurality of through holes are provided which are arranged along the surface direction of the power generation layer at the overlapping portion and penetrate the power generation layer in the thickness direction. Since it has reached a position beyond the boundary between the layer and the first conductive layer, the contact between the second conductive layer (the conductive material constituting the layer) and the first conductive layer beyond the boundary with the first conductive layer through the through hole. The area increases.
As a result, stable conduction between the first conductive layer and the second conductive layer can be ensured.

Here, when the through hole reaches a position beyond the boundary between the power generation layer and the first conductive layer, it means that at least a part of the through hole has penetrated to the first conductive layer.

(2) In the solar cell according to (1) above, one end of the through hole may be formed inside the first conductive layer.

According to the solar cell according to the above aspect, one end of the through hole is formed inside the first conductive layer that advances along the thickness direction of the first conductive layer. That is, since one end of the through hole is formed inside the first conductive layer, the contact area between the second conductive layer (the conductive material constituting the second conductive layer) and the first conductive layer is further increased. Reliable continuity can be ensured.

Here, one end of the through hole means not the top of the through hole on the tip side but the surface of the tip, for example, when the end of the through hole is flat, the entire flat portion is the first conductor. It means that it is invading (biting) into the layer. Further, when the through hole becomes thinner toward the tip side, it means that at least a part of the through hole is in surface contact with the first conductive layer.

(3) The solar cell according to (1) or (2) above may have a recessed recess in the first conductive layer at one end of the through hole.

According to the solar cell according to the above aspect, one end of the through hole is provided with a recessed recess in the first conductive layer. A part of the peripheral surface of this recess is exposed in the first conductive layer. As a result, conduction between the conductive material constituting the second conductive layer and at least the peripheral surface of the first conductive layer becomes possible, and stable conduction between the first conductive layer and the second conductive layer can be ensured.

(4) In the solar cell according to (3) above, the through holes may be formed at a pitch larger than 1 times the dimension along the arrangement direction of the recesses on the surface of the first conductive layer.

According to the solar cell according to the above aspect, since the through holes are formed at a pitch larger than 1 times the dimension along the arrangement direction of the recesses on the surface of the first conductive layer, the first conductive layer is divided. A peripheral surface that is conductive with the second electrode layer is formed over the entire inner peripheral surface of the recess.
As a result, more stable conduction between the first conductive layer and the second conductive layer can be ensured.

(5) In the solar cell according to (3) above, the through holes may be formed at a pitch of 1 times or less the dimension along the arrangement direction of the recesses on the surface of the first conductive layer.

According to the solar cell according to the above aspect, since the through holes are formed at a pitch of 1 times or less the dimension along the arrangement direction of the recesses on the surface of the first conductive layer, the inner peripheral surface of the recesses. Since the peripheral surface capable of conducting with the second electrode layer is continuously formed in the arrangement direction of the recesses, stable conduction between the first conductive layer and the second conductive layer can be ensured.

When forming the through hole, even if the purpose is to cut with laser pulse energy to the extent that the first conductive layer is barely perforated to avoid insufficient removal of the power generation layer (high connection resistance). When the laser intensity varies, recesses may be formed in the first conductive layer, but the recesses do not divide the first conductive layer, so that the recesses are spaced apart from each other. A through hole is formed as described above.

In this way, the recesses of the plurality of through holes are arranged at intervals along the surface direction of the first conductive layer, so that the conductive material constituting the second conductive layer is at least with the first conductive layer. Conduction is possible on the peripheral surface, and stable conduction between the first conductive layer and the second conductive layer is ensured.

Here, when the concave portion has a circular shape in a plan view, the dimension in the arrangement direction of the concave portion is the diameter of the concave portion. When the concave portion has another shape, it is the dimension in the arrangement direction of the concave portion on the surface of the first conductive layer.

(6) In the solar cell according to (4) above, the recess is formed in a circular shape on the surface of the first conductive layer in a plan view or an elliptical shape having a long axis or a short axis along the arrangement direction. The through holes may be formed at a pitch larger than twice the circular radius of the recess or the semi-major axis or semi-minor axis of the elliptical shape.

According to the solar cell according to the above aspect, the recess is formed in a circular shape on the surface of the first conductive layer in a plan view or an elliptical shape having a long axis or a short axis along the arrangement direction, and the through hole is formed. Since it is formed with a pitch larger than twice the circular radius of the recess or the semi-major axis or semi-minor axis of the elliptical shape, the pitch of the through holes can be easily and efficiently sized along the arrangement direction of the through holes. It can be set larger than 1 time.
It is preferable that the pitch of the through holes is formed to be 4 times or less the radius (or semimajor axis) of the recess.

(7) In the solar cell according to any one of (3) to (6) above, the depth of the recess is formed in a range of less than 80% with respect to the thickness of the first conductive layer. You may.

According to the solar cell according to the above aspect, the depth of the recess is formed in a range of less than 80% with respect to the thickness of the first conductive layer, so that damage to the first conductive layer is suppressed. can do.

(8) In the solar cell according to any one of (3) to (6) above, the depth of the recess may be 100% with respect to the thickness of the first conductive layer.

According to the solar cell according to the above aspect, since the depth of the recess is 100% with respect to the thickness of the first conductive layer, the first conductive layer is not divided and stable conduction can be ensured. ..

(9) In the solar cell according to any one of (1) to (8) above, the through holes have a pitch of one or more times the dimension along the arrangement direction of the through holes on the surface of the power generation layer. It may be formed by.

According to the solar cell according to the above aspect, the through holes are formed at a pitch of one or more times the dimension along the arrangement direction of the through holes on the surface of the power generation layer, and the plurality of through holes are formed in the power generation layer. Since the first conductive layer and the second conductive layer are arranged by the conductive material in the through hole, the first conductive layer and the second conductive layer are arranged so as to be arranged at intervals along the surface direction of Stable continuity can be ensured.

By forming the through holes at intervals on the surface of the power generation layer or circumscribing at the ends in the arrangement direction in this way, the margin when removing the power generation layer is increased, and the power generation layer is surely formed. The laser power can be increased to the extent that a through hole is formed in the. Further, even if there is a large variation when the laser power is increased, a through hole in which the connection portion is secured can be formed, and a through hole in which the first conductive layer is exposed can be efficiently formed in the power generation layer. Stable conduction can be ensured between the first conductive layer and the second conductive layer.

(10) In the solar cell according to any one of (1) to (8) above, the through holes are provided at a pitch smaller than 1 times the dimension along the arrangement direction of the through holes on the surface of the power generation layer. It may have been.

According to the solar cell according to the above aspect, since the through holes are provided at a pitch smaller than 1 times the dimension along the arrangement direction of the through holes on the surface of the power generation layer, the second through hole is provided on the inner peripheral surface of the recess. Since the peripheral surface that can conduct with the electrode layer is continuously formed in the arrangement direction of the recesses, stable conduction between the first conductive layer and the second conductive layer can be ensured.

In order to connect the first conductive layer and the second conductive layer, the power generation layer of the through hole forming portion is completely removed by a laser pulse to expose the first conductive layer, and the end face of the conductive material constituting the second conductive layer is exposed. Ideally, the first conductive layer is brought into contact with the surface and electrically connected.
However, when cutting the power generation layer with a laser pulse, if the laser pulse energy is too weak, the power generation layer remains, and the power generation layer is sandwiched between the first conductive layer and the second conductive layer, resulting in high connection resistance. The power generation performance will deteriorate.
On the other hand, if the laser pulse energy is made too strong, the entire power generation layer can be removed, but the first conductive layer is also removed by cutting, so that the connection resistance becomes high and the power generation performance deteriorates. It ends up.

Therefore, in order to reduce the connection resistance and form an ideal connection state between the first conductive layer and the second conductive layer, the laser pulse energy (output) should be stronger than the strength that the power generation layer can remove and penetrate. It is desirable that the energy is used to remove only a part of the first conductive layer in the hole portion. Therefore, by arranging the through holes at intervals on the surface of the power generation layer or forming them so as to circumscribe at the ends in the arrangement direction, the margin when the laser pulse energy (output) is increased becomes large, and the first 1 It is possible to prevent the conductive layer from being divided.
Further, in the removal of the film by the laser pulse, when the through hole is formed by irradiating the laser, it is removed from the central portion of the irradiated circle, so that the first conductive layer is removed only in the central portion of the through hole. It may be pulsed laser energy.

When the through holes are arranged and formed by a laser pulse, if the pitch between the through holes is narrow, the holes open only in the central portion of the through holes are continuously connected in the arrangement direction, and the first conductive layer is divided. Will be done. As a result, the portion where the second conductive layer is connected to the first conductive layer becomes smaller, and the power generation performance deteriorates.
As described above, the first conductive layer is cut in a line shape by arranging through holes penetrating the power generation layer at intervals on the surface of the power generation layer or forming them so as to circumscribe the ends in the arrangement direction. It is not divided and is cut into dots, and it is possible to take a large number of portions where the first conductive layer and the second conductive layer are connected, and the power generation performance is improved.

Here, when the through hole has a circular shape in a plan view, the dimension in the arrangement direction of the through hole is the diameter of the through hole. When the through hole has another shape, it is the dimension in the arrangement direction on the surface of the power generation layer of the through hole.

(11) In the solar cell according to any one of (1) to (10) above, the through hole has a circular shape on the surface of the power generation layer in a plan view or follows the arrangement direction of the through hole. It is formed in an elliptical shape having a major axis or a minor axis, and the through holes may be formed at a pitch equal to or more than twice the radius of the circular shape or the semimajor axis or the minor axis of the elliptical shape.

According to the solar cell according to the above aspect, the through hole is formed in a circular shape on the surface of the plan view power generation layer or an elliptical shape having a long axis or a short axis along the arrangement direction of the through holes, and penetrates. Since the holes are formed at a pitch that is at least twice the radius of the circle or the semi-major axis or the semi-minor axis of the ellipse, the pitch of the through holes can be easily and efficiently sized along the arrangement direction of the through holes. It can be set to 1 times or more.
It is preferable that the pitch of the through holes is formed to be 4 times or less the radius (or semi-major axis or short radius) of the through holes.

When the through hole is circular in a plan view, the through hole preferably has a diameter of about φ50 μm. The diameter of the surface of the first conductive layer of the through hole is preferably about φ1 μm to 45 μm, and more preferably φ5 μm to 10 μm.

(12) In the solar cell according to any one of (1) to (11) above, the through holes may be arranged in a plurality of rows.

According to the solar cell according to the above aspect, since the through-hole rows are arranged in a plurality of rows, the conductive area between the first conductive layer and the second conductive layer becomes large, and the first conductive layer and the second conductive layer The continuity between can be made more stable.

(13) A second aspect of the present invention is a method for manufacturing a solar cell, comprising a first conductive layer, a power generation layer including a photoelectric conversion layer, and a conductive material including a second conductive layer in this order. The first step of forming the first conductive layer and the power generation layer in this order on one surface of the base material and the pulse laser are used to arrange the first conductive layer and the power generation layer along the surface direction of the power generation layer to generate the power generation. A second step of forming a plurality of through holes formed by penetrating the layer in the thickness direction beyond the boundary between the power generation layer and the first conductive layer, and the conductive material on the power generation layer. This is a method for manufacturing a solar cell, comprising a third step of forming the second conductive layer.

According to the method for manufacturing a solar cell according to the above aspect, a first step of forming a first conductive layer and a power generation layer including a photoelectric conversion layer on one surface of a base material in this order, and a pulse laser are used. A second step of forming a plurality of through holes arranged along the plane direction of the power generation layer and penetrating the power generation layer in the thickness direction beyond the boundary between the power generation layer and the first conductive layer. The third step of forming the second conductive layer on the power generation layer with the conductive material is provided.
Therefore, the contact area between the second conductive layer (the conductive material constituting the second conductive material) and the first conductive layer beyond the boundary with the first conductive layer through the through hole increases.
As a result, stable conduction between the first conductive layer and the second conductive layer can be ensured.

(14) In the method for manufacturing a solar cell according to the above (13), in the second step, one end of the through hole may be formed in the first conductive layer.

According to the method for manufacturing a solar cell according to the above aspect, in the second step, one end of the through hole is formed in the first conductive layer, so that the second conductive layer (the conductive material constituting the second conductive layer) and the first one. The contact area with the conductive layer is further increased, and reliable conduction can be ensured.

(15) In the method for manufacturing a solar cell according to (14) above, in the second step, the through hole having a recessed recess in the first conductive layer may be formed at the end portion.

According to the method for manufacturing a solar cell according to the above aspect, since the end portion of the through hole is provided with a recessed recess in the first conductive layer, the conductive material constituting the second conductive layer and at least the first conductive layer It is possible to conduct conduction on the peripheral surface of the first conductive layer and the second conductive layer, and it is possible to secure stable conduction with the first conductive layer and the second conductive layer.

(16) The method for manufacturing a solar cell according to (15) above, in the second step, makes the through hole larger than 1 times the dimension along the arrangement direction of the recesses on the surface of the first conductive layer. It may be formed by pitch.
According to the method for manufacturing a solar cell according to the present invention, in the second step, the through holes are formed at a pitch larger than one times the dimension along the arrangement direction of the recesses on the surface of the first conductive layer. Therefore, since they are arranged at intervals along the surface direction of the first conductive layer, it is possible to prevent the first conductive layer from being divided.
In this way, the recesses of the plurality of through holes are arranged at intervals along the surface direction of the first conductive layer, so that the conductive material constituting the second conductive layer has a peripheral surface with the first conductive layer. Conduction is possible over the entire circumference of the above, and stable conduction between the first conductive layer and the second conductive layer is ensured.
Here, when the concave portion has a circular shape in a plan view, the dimension in the arrangement direction of the concave portion is the diameter of the concave portion. When the concave portion has another shape, it is the dimension in the arrangement direction of the concave portion on the surface of the first conductive layer.

(17) The method for manufacturing a solar cell according to (16) above has a circular shape on the surface of the first conductive layer in a plan view or a long axis or a short axis along the arrangement direction in the second step. The through hole having the concave portion formed in the elliptical shape may be formed at a pitch larger than twice the circular radius of the concave portion or the semi-major axis or short radius of the elliptical shape.
According to the method for manufacturing a solar cell according to the present invention, in the second step, the shape of the surface of the first conductive layer in a plan view is formed into a circular shape or an elliptical shape having a long axis or a short axis along the arrangement direction. Since the through holes having the recesses are formed at a pitch larger than twice the circular radius of the recesses or the semi-major axis or the semi-minor axis of the elliptical shape, the pitch of the through holes can be easily and efficiently set in the direction of the arrangement of the through holes. It can be set to be larger than 1 times the along dimension.
It is preferable that the pitch of the through holes is formed to be 4 times or less the radius (or semimajor axis) of the recess.

(18) In the method for manufacturing a solar cell according to any one of (15) to (17) above, the depth of the recess is set within a range of less than 80% with respect to the thickness of the first conductive layer. It may be formed.
According to the method for manufacturing a solar cell according to the above aspect, the depth of the recess is formed in a range of less than 80% with respect to the thickness of the first conductive layer, so that the first conductive layer is damaged. Can be suppressed.

(19) In the method for manufacturing a solar cell according to any one of (13) to (18) above, in the second step, the through holes are arranged in the arrangement direction of the through holes on the surface of the power generation layer. It may be formed at a pitch of 1 times or more the along dimension.
According to the method for manufacturing a solar cell according to the above aspect, in the second step, a plurality of through holes are formed at a pitch of one or more times the dimension along the arrangement direction of the through holes on the surface of the power generation layer. Since the through holes are arranged at intervals along the surface direction of the power generation layer or extrinsically at the ends in the arrangement direction, the conductive material in the through holes causes the first conductive layer and the second conductive layer to be arranged. Stable continuity can be ensured.

(20) The method for manufacturing a solar cell according to any one of (13) to (19) above, in the second step, has a circular shape on the surface of the power generation layer in a plan view or an arrangement of the through holes. The through hole formed in an elliptical shape having a long axis or a short axis along the direction may be formed at a pitch equal to or more than twice the radius of the circular shape or the long radius or the short radius of the elliptical shape.
According to the method for manufacturing a solar cell according to the above aspect, in the second step, an elliptical through hole having a circular shape on the surface of the power generation layer in a plan view or an elliptical shape having a long axis or a short axis along the arrangement direction is formed. , Since it is formed with a pitch that is at least twice the radius of the circle or the semi-major axis or the semi-minor axis of the ellipse, the pitch of the through holes can be easily and efficiently increased to at least one times the dimension along the arrangement direction of the through holes. Can be set.
It is preferable that the pitch of the through holes is formed to be 4 times or less the radius (or semi-major axis or short radius) of the through holes.

(21) In the method for manufacturing a solar cell according to any one of (13) to (20) above, the through holes may be formed in a plurality of rows in the second step.

According to the method for manufacturing a solar cell according to the above aspect, since the through holes are formed in a plurality of rows in the second step, the conduction between the first conductive layer and the second conductive layer can be more stabilized.

According to the solar cell and the method for manufacturing a solar cell according to the present invention, stable conduction between the first conductive layer and the second conductive layer can be ensured.

It is a top view explaining the schematic structure of the solar cell which concerns on 1st Embodiment of this invention. FIG. 1 is a vertical cross-sectional view shown by arrow II-II in FIG. 1 for explaining a schematic configuration of a solar cell according to a first embodiment. It is a figure explaining the schematic structure of the solar cell which concerns on 1st Embodiment, and is the perspective view which conceptually shows the through-hole row before the 2nd conductive layer of the arrow III part in FIG. 2 is formed. It is a figure explaining the schematic structure of the through-hole row in the solar cell which concerns on 1st Embodiment, (a) is the plan view which the arrangement of the through-hole row is seen from the upper surface (surface) side of the power generation layer, (b). ) Is a vertical sectional view shown by arrow IVB-IVB in (a). It is a vertical sectional view conceptually explaining the power generation layer in the solar cell which concerns on 1st Embodiment. It is a figure explaining the schematic structure at the time of the through hole circumscribing in the solar cell of 1st Embodiment, (a) is the plan view which the arrangement of the through hole row was seen from the upper surface (surface) side of the power generation layer. (B) is a vertical cross-sectional view shown by arrow VIB-VIB in (a). It is a vertical sectional view explaining the schematic structure of the solar cell which concerns on 2nd Embodiment of this invention. It is a figure explaining the schematic structure of the solar cell which concerns on 2nd Embodiment, and is the perspective view which conceptually shows the through-hole row before the 2nd conductive layer of the arrow VIII part in FIG. 7 is formed. It is a figure explaining the schematic structure of the solar cell which concerns on the 1st modification of 2nd Embodiment, (a) is the plan view which the arrangement of the through-hole row is seen from the upper surface (surface) side of the power generation layer, (a). b) is a vertical sectional view shown by arrow IXB-IXB in (a). It is a figure explaining the schematic structure of the solar cell which concerns on the 2nd modification of 2nd Embodiment, (a) is the plan view which the arrangement of the through-hole row is seen from the upper surface (surface) side of the power generation layer, (a). b) is a vertical sectional view shown by arrow XB-XB in (a). It is a figure explaining the schematic structure of the solar cell which concerns on the 3rd modification of 2nd Embodiment, (a) is the plan view which the arrangement of the through-hole row is seen from the upper surface (surface) side of the power generation layer, (a). b) is a vertical sectional view shown by arrow XIB-XIB in (a). It is a figure explaining the schematic structure of the solar cell which concerns on 4th modification of 2nd Embodiment, (a) is the plan view which the arrangement of the through-hole row is seen from the upper surface (surface) side of the power generation layer, (a). b) is a vertical sectional view shown by arrow XIIB-XIIB in (a). It is a perspective view which conceptually shows the group of through-hole rows before the formation of the 2nd conductive layer which explains the schematic structure of the solar cell which concerns on 3rd Embodiment of this invention. It is a top view which shows the inside part | part explaining the schematic structure of the conventional solar cell. FIG. 1 is a vertical cross-sectional view shown by arrow XV-XV in FIG. 1 for explaining a schematic configuration of a conventional solar cell.

[First Embodiment]
Hereinafter, the solar cell according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 5. 1 to 5 are views for explaining a schematic configuration of a solar cell according to a first embodiment of the present invention, FIG. 1 is a plan view, and FIG. 2 is a vertical section shown by arrow view II-II in FIG. It is a plan view. Further, FIG. 3 is a perspective view conceptually showing a row of through holes before the second conductive layer of the arrow III portion in FIG. 2 is formed. 4A and 4B are views for explaining the schematic configuration of the through-hole rows, and FIG. 4A is a plan view of the arrangement of the through-hole rows as viewed from the upper surface (surface) side of the power generation layer, and is a plan view of FIG. (B) is a vertical cross-sectional view shown by arrow IVB-IVB in (a) of FIG. Further, FIG. 5 is a vertical cross-sectional view for conceptually explaining the power generation layer. The figures shown in the present specification may be partially or wholly enlarged for the sake of explanation.

In the present specification, one end side is indicated by reference numeral F, the other end side is indicated by reference numeral R, and the upper surface (surface) side is indicated by reference numeral A.
Further, in the present specification, the lower limit value and the upper limit value are included in the numerical limitation range described with “～” in between. The numerical value indicated as "greater than or equal to" includes the value in the numerical range. The value indicated as "less than" does not include the value in the numerical range.

As shown in FIGS. 1 and 2, the solar cell 100 according to the first embodiment includes, for example, an insulating base material 10, a plurality of first conductive layers 20 formed on the upper surface of the insulating base material 10, and a plurality of first conductive layers 20. A power generation layer 30 arranged so as to cover the surfaces of the plurality of first conductive layers 20, a plurality of second conductive layers 40 formed on the surface side of the power generation layer 30, and a through-hole row 50 penetrating the power generation layer 30. And have.
Further, a leader wire (not shown) extending to the outside is connected to the first conductive layer 20F (20) on the one end side F and the first conductive layer 20R (20) on the other end side R.

The electrons generated in each power generation layer 30 move toward the first conductive layer 20 in each power generation layer 30. Then, the electrons that have moved to the first conductive layer 20 pass through the conductive portion 41 formed in the through-hole row 50 and formed of the conductive material forming the second conductive layer 40, and the first conductive layer on the other end side R. Move to 20. In this way, the electrons generated in each of the power generation layers 30 sequentially move to the first conductive layer 20 on the other end side R arranged adjacent to each other. The holes generated in the power generation layer 30 move to the second conductive layer 40 on the surface side A.
As a result, the solar cell 100 functions as an electric module having a plurality of power generation layers 30 arranged in series.

<Insulating base material>
As shown in FIGS. 1 and 2, the insulating base material 10 is formed, for example, in a rectangular shape in a plan view. The insulating base material 10 has an insulating property.
The material for forming the insulating base material 10 is not particularly limited, but a known insulator may be applied, and in addition to the insulating resin, for example, a metal oxide constituting the insulating layer of a conventional electronic device is used. May be good. Specifically, zirconium dioxide, silicon dioxide, aluminum oxide _{_{(AlO, Al 2 O 3)}} , magnesium oxide (MgO), nickel oxide (NiO) and the like. Of these, aluminum oxide (III) (Al ₂ O ₃ ) is particularly preferable.
The insulator forming the insulating base material 10 may be one kind or two or more kinds.

When the material of the insulating base material 10 is a synthetic resin, for example, a polyacrylic resin, a polycarbonate resin, a polyester resin, a polyimide resin, a polystyrene resin, a polyvinyl chloride resin, a polyamide resin or the like may be used as the synthetic resin. good. Among these, polyester resins, particularly polyethylene naphthalate (PEN) and polyethylene terephthalate (PET), are suitable for producing thin, light and flexible solar cells. The thickness of the insulating base material 1 is not particularly limited, and is preferably 0.01 mm to 3 mm, for example.

Further, a structure in which a metal oxide and a synthetic resin are laminated, or a structure in which the entire surface side of the metal foil is insulated (for example, oxidation treatment, alumite treatment, coating of an insulating material, etc.) may be used.

<First conductive layer>
As shown in FIGS. 1 and 2, the first conductive layer 20 is formed (laminated) on the surface side (upper surface) A of the insulating base material 10.
In this embodiment, for example, four (plurality) first conductive layers 20 formed in a rectangular shape in a plan view are arranged along the surface of the insulating base material 10 at a distance of 20 G from each other.

The material of the first conductive layer 20 is not particularly limited as long as it has conductivity, and for example, gold, silver, copper, aluminum, tungsten, nickel, titanium, niobium, molybdenum, cobalt, ruthenium, indium, tin and chromium. In addition to any one or more metals selected from the group consisting of these, alloys or oxides thereof, or a laminated film thereof is suitable.
The thickness of the first conductive layer 20 is not particularly limited, and is preferably 10 nm to 1000 nm, for example.

<Power generation layer>
As shown in FIGS. 1 and 2, for example, the power generation layer 30 is formed (laminated) on the surface side (upper surface) A of the first conductive layer 20 so as to cover the first conductive layer 20. Specifically, it is formed so as to cover the surface side (upper surface) A of the first conductive layer 20 and fill the interval 20G formed between the adjacent first conductive layers 20.

As shown in FIGS. 1 to 3, a through hole row 50 penetrating in the thickness direction is formed in the power generation layer 30. The through-hole row 50 is arranged in the overlapping portion 42 where the first conductive layer 20 and the second conductive layer 40 overlap when viewed in a plan view, and is formed along the interval 20G between the first conductive layers 20.
As shown in FIGS. 3 and 4, the through-hole rows 50 are arranged linearly (along the straight line) along the plane direction of the power generation layer 30 when viewed in a plan view, and are formed at intervals. It is provided with a plurality of through holes 51.
The through hole 51 is formed by, for example, irradiating a laser beam oscillated by a pulse laser processing apparatus. The through hole 51 shown in FIG. 3 is conceptually shown, and the vertical cross-sectional shape is not limited to this.

The through hole 51 is formed in a substantially circular shape in a plan view, and for example, the diameter D1 on the surface of the power generation layer 30 is set to φ50 μm. The diameter D1 of the through hole 51 can be arbitrarily set, but for example, it is preferably set to 10 μm or more and 100 μm or less.

The pitch P shown in FIG. 4A is the distance between the centers of the adjacent through holes 51. The pitch P of the through holes 51 in the through hole row 50 can be arbitrarily set. When the interval 30G of the through hole 51 is provided (interval 30G> 0 (μm)), for example, the pitch (cycle) P for irradiating the pulse laser is 1 times (radius) the diameter D1 (50 μm) of the through hole 51. Double) Set larger.
Further, it is preferable that the pitch P of the through hole 51 is set to, for example, 1 time or more and 2 times or less (2 times or more and 4 times or less with respect to the radius) with respect to the diameter D1 of the through hole 51.

That is, for example, when the diameter D1 of the through hole 51 is 10 μm or more and 100 μm or less, the pitch P of the through hole 51 is preferably 10 μm or more and 200 μm or less, and more preferably 10 μm or more and 100 μm or less. be.

Further, the through hole 51 reaches the surface (upper surface) of the first conductive layer 20 on the tip side, exposes the surface of the first conductive layer 20 to the surface side (opening side) A of the through hole 51, and the through hole 51. The end portion (the surface on the tip end side) of the above reaches a position beyond the boundary between the power generation layer 30 and the first conductive layer 20, and is formed so as to enter the first conductive layer 20.
The conductive material constituting the second conductive layer 40 is configured to be able to conduct surface contact with the first conductive layer 20 at the end of the through hole 51.

As shown in FIG. 5, the power generation layer 30 includes, for example, a hole transport layer 31, a photoelectric conversion layer 32, and an electron transport layer 33 in this embodiment. Further, for example, it is preferable that the electron transport layer 33, the photoelectric conversion layer 32, and the hole transport layer 31 are arranged in this order from the first conductive layer 20. Further, although the hole transport layer 31 and the electron transport layer 33 are not essential, it is preferable to include them.

In the solar cell 100, when the photoelectric conversion layer 32 absorbs light, electrons and holes are generated in the layer. The holes are received by the hole transport layer 31 and move to the working electrode (positive electrode) formed by the second conductive layer 40. On the other hand, the electrons move to the counter electrode (negative electrode) formed by the first conductive layer 20 via the electron transport layer 33.

(Hole transport layer)
The hole transport layer 31 functions as a layer for transporting the holes generated in the photoelectric conversion layer 32 to the second conductive layer 40.
The hole transport layer 31 is preferably arranged between the second conductive layer 40 and the photoelectric conversion layer 32.
A part of the hole transport layer 31 may be immersed in the photoelectric conversion layer 32 (may form a complicated structure with the photoelectric conversion layer 32), or may be formed into a thin film on the photoelectric conversion layer 32. It may be arranged. When the hole transport layer 31 is present in the form of a thin film, the preferable lower limit is 1 nm and the preferable upper limit is 2000 nm. That is, the thickness of the hole transport layer 31 when it exists in the form of a thin film is preferably 1 nm or more and the upper limit is 2000 nm or less. When the thickness of the hole transport layer 31 is 1 nm or more, electrons can be sufficiently blocked. If the thickness of the hole transport layer 31 is 2000 nm or less, resistance during hole transport is unlikely to occur, and the photoelectric conversion efficiency becomes high. The thickness of the hole transport layer 31 is more preferably in the range of 3 nm or more and 1000 nm or less, and further preferably 5 nm or more and 500 nm or less.

The material of the hole transport layer 31 is not particularly limited and may be an organic material or an inorganic material, for example, a P-type conductive polymer, a P-type low molecular weight organic semiconductor, and a P-type metal oxide. , P-type metal sulfide, surfactant and the like. Specific examples thereof include compounds having a thiophene skeleton such as poly (3-alkylthiophene). For example, a conductive polymer having a triphenylamine skeleton, a polyparaphenylene vinylene skeleton, a polyvinylcarbazole skeleton, a polyaniline skeleton, a polyacetylene skeleton and the like can also be mentioned. Further, for example, a compound having a porphyrin skeleton such as a phthalocyanine skeleton, a naphthalocyanine skeleton, a pentacene skeleton, a benzoporphyrin skeleton, a spirobifluorene skeleton and the like can be mentioned. Further, molybdenum oxide, vanadium oxide, tungsten oxide, nickel oxide, copper oxide, tin oxide, molybdenum sulfide, tungsten sulfide, copper sulfide, tin sulfide, etc., fluorogroup-containing phosphonic acid, carbonyl group-containing phosphonic acid, CuSCN, CuI, etc. Examples thereof include carbon-containing materials such as copper compounds, carbon nanotubes, and graphene.
The type of material constituting the hole transport layer 31 may be one type or two or more types.

(Photoelectric conversion layer)
The photoelectric conversion layer 32 is a layer that converts the received light into electrical energy and performs photoelectric conversion. The photoelectric conversion layer contains a perovskite compound, and electrons are generated by the perovskite compound by light irradiation.
The type of perovskite compound is not particularly limited, and a known perovskite compound used in a solar cell can be applied, has a crystal structure, and exhibits light absorption by bandgap excitation like a typical compound semiconductor. Is preferable. For example, it is known that CH ₃ NH ₃ PbI ₃ ^{, which is a known perovskite compound, has an extinction coefficient (cm -1} ) per unit thickness that is an order of magnitude higher than that of a sensitizing dye of a dye-sensitized solar cell. There is.

The thickness of the photoelectric conversion layer 32 is not particularly limited, and is preferably 10 nm to 10000 nm, more preferably 50 nm to 1000 nm, and even more preferably 100 nm to 500 nm.
When the thickness of the photoelectric conversion layer 32 is at least the lower limit of the above range, the light absorption efficiency of the photoelectric conversion layer 32 is increased, and more excellent photoelectric conversion efficiency can be obtained.
When the thickness of the photoelectric conversion layer 32 is not more than the upper limit of the above range, the efficiency of photoelectrons generated in the photoelectric conversion layer 32 reaching the first conductive layer 20 is improved, and more excellent photoelectric conversion efficiency is obtained. Be done.

(Electronic transport layer)
The electron transport layer 33 functions as a layer for transporting the electrons generated in the photoelectric conversion layer 32 to the first conductive layer 20.
The material of the electron transport layer 33 is not particularly limited, and may be an organic material or an inorganic material. For example, an N-type semiconductor of a known electron transport layer of a solar cell can be applied.
Examples of the inorganic material include copper compounds such as CuI, CuSCN, CuO and Cu2O, and nickel compounds such as NiO.

The electron transport layer 33 may be composed of only a thin-film electron transport layer (buffer layer), but preferably includes a porous electron transport layer 33. In particular, when the photoelectric conversion layer 32 is a composite film in which an organic semiconductor or an inorganic semiconductor moiety and an organic-inorganic perovskite compound moiety are composited, a more complicated composite film (more complicated structure) can be obtained, and photoelectric conversion can be obtained. Since the efficiency is high, it is preferable that the composite film is formed on the porous electron transport layer.

The preferred lower limit of the thickness of the electron transport layer 33 is 1 nm, and the preferred upper limit is 2000 nm. That is, the thickness of the electron transport layer 33 is preferably 1 nm or more and 2000 nm or less. When the thickness of the electron transport layer 33 is 1 nm or more, holes can be sufficiently blocked. When the thickness of the electron transport layer 33 is 2000 nm or less, it is unlikely to become a resistance during electron transport, and the photoelectric conversion efficiency becomes high. The thickness of the electron transport layer 33 is more preferably 3 nm or more and 1000 nm or less, and further preferably 5 nm or more and 500 nm or less.

The type of material constituting the electron transport layer 33 may be one type or two or more types.
The number of layers of the electron transport layer 33 may be one layer or two or more layers.
The total thickness of the electron transport layer 33 is not particularly limited, but is preferably about 5 nm to 500 nm, for example. When it is 5 nm or more, the effect of suppressing the above loss can be sufficiently obtained, and when it is 500 nm or less, the internal resistance can be suppressed low.

The thickness of the power generation layer 30 is not particularly limited, and for example, 10 nm to 10 μm is preferable, 50 nm to 1 μm is more preferable, and 100 nm to 1 μm is further preferable.
When the thickness of the power generation layer 30 is at least the lower limit of the above range, a high electromotive force can be obtained. When the thickness of the power generation layer 30 is not more than the upper limit value in the above range, the internal resistance can be further reduced.

<Second conductive layer>
As shown in FIGS. 1 and 2, the second conductive layer 40 is formed (laminated) on the front surface side (upper surface) A of the power generation layer 30.
The second conductive layer 40 is formed on the surface side (upper surface) A of the adjacent power generation layer 30 so as to face each of the plurality of first conductive layers at a distance of 40 G.
Each of the second conductive layers 40 is formed with an overlapping portion 42 with the first conductive layer 20 adjacent to the first conductive layer facing the first conductive layer when viewed from a direction (planar view) perpendicular to the surface of the power generation layer. There is.

The conductive material constituting the second conductive layer 40 fills, for example, the through-hole rows 50 formed between the four adjacent power generation layers 30 and covers the surface side (upper surface) A of the power generation layers 30. Is formed in.
In the second conductive layer 40 arranged on the other end side R of FIGS. 1 and 2, since the power generation layer 30 corresponding to the other end side R is not arranged, the second conductive layer 40 is passed through the other end side R of the power generation layer 30. It is formed so that the end faces are sequentially electrically connected to the first conductive layer 20 through the through holes 51 that reach the first conductive layer 20 facing each other and communicate with the first conductive layer 20. ..

The material for forming the second conductive layer 40 is not particularly limited as long as it is a conductive layer, and a material capable of forming a transparent layer is preferable. For example, metal oxides such as tin-doped tin oxide (ITO), fluorine-doped tin oxide (FTO), antimony-doped tin oxide (ATO), tin dioxide (SnO2), and zinc oxide (ZnO) are suitable. In addition, inorganic transparent conductive films such as gallium-added zinc oxide (GZO), aluminum-added zinc oxide (AZO), indium, gallium, zinc, and amorphous semiconductors (IGZO) composed of oxygen, and conductive carbon films such as graphene. An ultrathin metal film capable of transmitting light or a laminated film thereof may be used.
As the ultrathin metal film, any one or more metals selected from the group consisting of gold, silver, copper, aluminum, tungsten, nickel and chromium can be applied.
The type of material constituting the second conductive layer 40 may be one type or two or more types.
The thickness of the second conductive layer 40 may be arbitrarily set, and is preferably 10 nm to 500 nm, for example.

In the first embodiment, as shown in FIG. 6, the solar cell 100 may be formed so that, for example, the through holes 51 arranged adjacent to each other are circumscribed in the arrangement direction.
FIG. 6 is a diagram for explaining a schematic configuration when the through holes 51 are externally attached to the solar cell 100, and FIG. 6 (a) is a plane in which the arrangement of the through hole rows is viewed from the upper surface (surface) side of the power generation layer. FIG. 6B is a vertical cross-sectional view shown by arrow VIB-VIB in FIG. 6A.

At this time, the pitch P of the through holes 51 in the solar cell 100 is formed to be once (twice the radius) the diameter D1 of the through holes 51.
Therefore, the wall portion of the power generation layer 30 is not formed between the through holes 51, but the surface of the first conductive layer 20 is exposed substantially flat to form the second conductive layer 40. The conductive material is connected to the first conductive layer 20 at the end face, and the first conductive layer 20 and the second conductive layer 40 are stably conductive.

Next, the method for manufacturing the solar cell according to the first embodiment will be described.
The method for manufacturing the solar cell 100 according to the first embodiment is, for example, a first step of forming a first conductive layer 20 and a power generation layer 30 on the upper surface (one surface) of the insulating base material 10 in this order. A second step of forming a through-hole row 50 in the power generation layer 30 by forming a plurality of through holes 51 penetrating in the thickness direction along the surface direction of the power generation layer 30 at intervals using a pulse laser. And a third step of sticking a conductive material on the power generation layer 30 to form the second conductive layer 40. This manufacturing method is an example, and is not limited to the following manufacturing method.

(1) Preparation of Insulating Base Material The insulating base material 10 can use the above-mentioned insulating base material, and can be manufactured by a well-known manufacturing method.

(2) First Step In the first step, the first conductive layer 20 and the power generation layer 30 are formed in this order on the upper surface (surface, one surface) of the insulating base material 10.

(Formation of the first conductive layer 20)
The method of forming the first conductive layer 20 on the upper surface of the insulating base material 10 is not particularly limited, and for example, a well-known film forming method such as a sputtering method or a vapor deposition method can be applied.

The method of forming the power generation layer 30 on the first conductive layer 20 is not particularly limited, and examples thereof include known film forming methods such as a sputtering method, a coating method, and a vapor deposition method.
When obtaining a solar cell having a hole transport layer 31 and an electron transport layer 33 on both sides of the photoelectric conversion layer 32, for example, the following method can be mentioned.

The electron transport layer 33 is formed on the first conductive layer 20.
The method for forming the electron transport layer 33 is not particularly limited, and examples of a known method capable of forming a dense layer made of an N-type semiconductor with a desired thickness include a sputtering method, a vapor deposition method, and a dispersion including a precursor of the N-type semiconductor. Examples thereof include a sol-gel method in which a liquid is applied.

Examples of the precursor of the N-type semiconductor include titanium tetrachloride (TiCl ₄ ), peroxotitanic acid (PTA), titanium alkoxide such as titanium ethoxyoxide and titanium isopropoxide (TTIP), zinc alkoxide, alkoxysilane, and zirconium. Examples thereof include metal alkoxides such as alkoxides.

In the solar cell of this embodiment, a base layer (not shown) may be formed between the electron transport layer 33 and the photoelectric conversion layer 32.
When forming the base layer that supports the photoelectric conversion layer 32, the method is not particularly limited, and for example, a method for forming a porous semiconductor layer that supports a sensitizing dye of a conventional dye-sensitized solar cell can be applied.

As a specific example, for example, a paste containing fine particles and a binder made of an N-type semiconductor or an insulator is applied to the surface of the electron transport layer 33 by a doctor blade method, dried, and fired to obtain a porous surface made of fine particles. A formation can be formed.
Further, by spraying the fine particles onto the surface of the electron transport layer 33, a porous or non-porous base layer made of the fine particles can be formed.

A photoelectric conversion layer 32 made of a perovskite compound is formed on the surface of the base layer. The method for forming the photoelectric conversion layer 32 is not particularly limited, and examples thereof include the following methods. That is, a raw material solution in which a perovskite compound or a precursor of a perovskite compound is dissolved is applied to the surface of the base layer, impregnated inside the base layer, and a solution layer composed of a solution having a desired thickness is present on the surface. , A method of drying the solvent.

At least a part of the raw material solution applied to the base layer permeates into the porous membrane of the base layer, crystallization proceeds as the solvent dries, and the perovskite compound adheres and deposits in the porous membrane.
Further, by applying a sufficient amount of the raw material solution, the raw material solution that has not penetrated into the porous film is formed with an upper layer made of a perovskite compound on the surface of the base layer as the solvent dries. The perovskite compound constituting the upper layer and the perovskite compound inside the base layer are integrally formed, and integrally constitute the photoelectric conversion layer 32.

The perovskite compound used in the present embodiment is not particularly limited as long as it can generate an electromotive force by light absorption, and a known perovskite compound can be applied.

In the formation of the photoelectric conversion layer 32, examples of the precursor contained in the raw material solution include a halide of lead.
A single raw material solution containing a lead halide may be applied to the base layer, or a mixed raw material solution containing two types of halides individually may be applied to the base layer.

The solvent of the raw material solution is not particularly limited as long as it is a solvent that dissolves the raw material and does not damage the underlying layer, and is, for example, an ester, a ketone, an ether, an alcohol, a glycol ether, an amide, a nitrile, a carbonate, or a halogenated hydrocarbon. , Glyco, sulfone, sulfoxide, formamide and other compounds.

The concentration of the raw material in the raw material solution is not particularly limited, and is preferably a concentration that is sufficiently dissolved and has a viscosity that allows the raw material solution to permeate into the porous membrane.

The amount of the raw material solution to be applied to the base layer is not particularly limited, and for example, the upper that permeates all or at least a part of the porous film and has a thickness of about 1 nm to 1 μm on the surface of the porous film. The coating amount is preferably such that a layer is formed.

The method of applying the raw material solution to the base layer is not particularly limited, and known methods such as a gravure coating method, a bar coating method, a printing method, a spray method, a spin coating method, a dip method, and a die coating method can be applied.

The method of drying the raw material solution applied to the base layer is not particularly limited, and known methods such as natural drying, vacuum drying, and warm air drying can be applied.
The drying temperature of the raw material solution applied to the base layer may be a temperature at which crystallization of the perovskite compound proceeds sufficiently, and examples thereof include a range of 40 to 150 ° C.

The method for forming the hole transport layer 31 is not particularly limited. For example, a solution in which a P-type semiconductor is dissolved or dispersed in a solvent in which the perovskite compound constituting the photoelectric conversion layer 32 is difficult to dissolve is prepared, and this solution is photoelectrically converted. A method of obtaining the hole transport layer 31 by applying it to the surface of the layer 32 and drying it can be mentioned.
By the above steps, a layer including the electron transport layer 33, the photoelectric conversion layer 32, and the hole transport layer 31 can be formed in this order.

(3) Second Step In the second step, a pulsed laser is used to linearly view a plurality of through holes 51 arranged at intervals of penetrating in the thickness direction along the plane direction of the power generation layer 30. By forming, a through hole row 50 is formed.

Various laser irradiation devices can be used as the laser irradiation device for forming the through hole 51. For example, the laser irradiation device can use an ultraviolet laser, a green laser, or an infrared laser, and a green laser is desirable from the viewpoint of workability and cost.

The conditions for forming the through hole 51 are shown below. The following conditions show an example and are not limited to the following conditions.
[Pulse frequency]
The pulse frequency is preferably 10 kHz to 500 kHz. Further, in order to scan the laser pulse with high accuracy by the galvanometer mirror method, the pulse frequency is preferably 100 kHz to 300 kHz, for example.
〔output〕
The laser output is preferably about 0.5 μJ to 60 μJ per pulse.
[Scan speed]
The scanning speed when scanning with the galvanometer mirror is preferably, for example, 0.1 m / sec to 10 m / sec. Further, from the viewpoint of processing accuracy, the scanning speed is preferably, for example, 3 m / sec to 6 m / sec.

(4) Third Step In the third step, the second conductive layer 40 is formed on the power generation layer 30.
The method for forming the second conductive layer 40 is not particularly limited, and examples thereof include known film forming methods such as a sputtering method and a vapor deposition method.
The method for manufacturing the solar cell 100 is an example, and is not limited to the above method, and can be arbitrarily set as long as the gist of the invention is not changed.

According to the solar cell 100 according to the first embodiment, a through-hole row 50 penetrating the power generation layer 30 is formed in a region of the first conductive layer 20 and the second conductive layer 40 corresponding to the overlapping portion 42 in the plane direction. Then, the conductive material forming the second conductive layer 40 extends into the through-hole row 50 and reaches the first conductive layer 20, so that the conductive material forming the second conductive layer 40 is first on the end face. It is electrically connected to the conductive layer 20.
As a result, damage to the first conductive layer 20 is suppressed, and through holes 51 in which the first conductive layer 20 is exposed are efficiently formed in the power generation layer 30, and the first conductive layer 20 and the second conductive layer 40 are formed. Stable continuity can be ensured during the period.

According to the solar cell 100 according to the first embodiment, since the through hole 51 is formed beyond the boundary between the power generation layer 30 and the first conductive layer 20, it is connected to the first conductive layer 20 through the through hole 51. The contact area between the second conductive layer (conducting material) 40 and the first conductive layer 20 that crosses the boundary increases. As a result, stable conduction between the first conductive layer 20 and the second conductive layer 40 can be ensured.

According to the method for manufacturing the solar cell 100 according to the first embodiment, since a plurality of through holes 51 penetrating in the thickness direction along the surface direction of the power generation layer 30 are formed at intervals of 30 G, power generation is performed. The density of the laser power (output) in the layer 30 is relatively low as compared with the case where the continuous scribing groove is formed, and the margin when removing the power generation layer 30 can be increased.
As a result, the laser power can be increased to the extent that a through hole is surely formed in the power generation layer 30, and further, the density of the laser power becomes relatively low, so that the laser power is increased and a large variation occurs. Even if it does occur, it is possible to prevent damage to the first conductive layer 20.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS. 7 and 8.
7 and 8 are views for explaining the schematic configuration of the solar cell according to the second embodiment of the present invention, FIG. 7 is a vertical sectional view, and FIG. 8 is a second conductivity of the arrow VIII portion in FIG. It is a perspective view which conceptually shows the through hole row before a layer is formed.

As shown in FIGS. 7 and 8, the solar cell 200 according to the second embodiment includes, for example, an insulating base material 10, a first conductive layer 20, a power generation layer 30, a second conductive layer 40, and power generation. A through-hole row 250 penetrating the layer 30 is provided.

The electrons generated in each power generation layer 30 move toward the second conductive layer 40 in each power generation layer 30. Then, the electrons that have moved to the second conductive layer 40 pass through the conductive portion 241 formed in the through-hole row 250 and formed of the conductive material constituting the second conductive layer 40, and the first conductive layer on the other end side R. Move to 20 in sequence.
The second embodiment is different from the first embodiment in that the through hole row 250 and the through hole 251 are provided instead of the through hole row 50 and the through hole 51. Others are the same as those in the first embodiment, so the same reference numerals are given and the description thereof will be omitted.

As shown in FIG. 8, the through hole row 250 includes, for example, a plurality of through holes 251 formed at intervals. The through hole row 250 is formed in the overlapping portion 42.
The through hole 251 penetrates the power generation layer 30 and extends in the thickness direction of the first conductive layer 20, and the tip side (end portion) enters the first conductive layer 20 to form a digging recess (recess). It has 252.
The conductive material constituting the second conductive layer 40 is configured to make surface contact with the first conductive layer 20 in the recess (end) 252 of the through hole 251.
The depth t1 of the digging recess (recess) 252 is preferably formed in a range of 0% or more and less than 80% with respect to the thickness t0 of the first conductive layer 20, for example, 2% or more and 70% or less. It is more preferable that it is formed in the range of 5% or more and 50% or less. In the present embodiment, as shown by reference numeral 520X in FIGS. 14 and 15, the proportion of through holes in which the first conductive layer is removed and the insulating base material is exposed is 0%. preferable.

When forming the through hole 251 provided with the digging recess 252, the laser power is increased. For example, when the recess 252 is not formed, the laser output is preferably about 20 μJ, but when the recess 252 is formed, it is preferably 25 μJ.

The through hole 251 is formed in a substantially circular shape in a plan view, and for example, the diameter D1 on the surface of the power generation layer 30 is set to φ50 μm. The diameter D1 of the through hole 251 can be arbitrarily set, but it is preferably set to, for example, 10 μm or more and 100 μm or less.

The pitch P of the through holes 251 in the through hole row 250 can be arbitrarily set. When the interval 30G of the through hole 251 is provided (interval 30G> 0 (μm)), for example, the pitch (cycle) P for irradiating the pulse laser is once the diameter D1 (50 μm) of the through hole 251 (radius). Double) Set larger.
Further, it is preferable that the pitch P of the through hole 251 is set to, for example, 1 time or more and 2 times or less (2 times or more and 4 times or less with respect to the radius) with respect to the diameter D1 of the through hole 251.

According to the solar cell 200 according to the second embodiment, the through hole 251 is provided with a digging recess 252 formed in the first conductive layer 20, and conduction is possible on the peripheral surface of the digging recess 252, so that the conduction area is large. By increasing the number, the conduction between the first conductive layer 20 and the second conductive layer 40 can be stabilized.
Further, since the depth t1 of the dug recess 252 is formed in a range of less than 80% with respect to the thickness t0 of the first conductive layer 20, damage to the first conductive layer 20 is suppressed.

[First modification (second embodiment)]
Next, a first modification of the second embodiment of the present invention will be described with reference to FIG.
FIG. 9 is a diagram illustrating a schematic configuration of a solar cell according to a first modification of the second embodiment, and FIG. 9A is a view of the arrangement of through-hole rows as viewed from the upper surface (surface) side of the power generation layer. It is a plan view, and FIG. 9B is a vertical sectional view shown by arrow IXB-IXB in FIG. 9A. Note that FIG. 9 illustrates a multi-stage cylindrical through hole in the power generation layer 30 and the first conductive layer 20 for convenience. This is because the through hole 251 in the modified example (second embodiment) has a diameter D2 of the dug recess (recess) 252 on the surface of the first conductive layer 20 smaller than the diameter D1 on the surface of the power generation layer 30. This is a conceptual illustration of this. The same shall apply hereinafter.

The first modification differs from the second embodiment in that the diameter D2 on the surface of the first conductive layer 20 of the dug recess (recess) 252 in the through hole 251 is smaller than the diameter D1 on the surface of the power generation layer 30. It is a point that is said to be.
As shown in FIG. 9, the pitch P of the through hole 251 is formed to be larger than the diameter D1 on the surface of the power generation layer 30 of the through hole 251. As a result, the adjacent through holes 251 are arranged with an interval of 21G.

The depth t1 of the dug recess (recess) 252 of the through hole 251 is preferably formed in a range of 0% or more and less than 80% with respect to the thickness t0 of the first conductive layer 20, for example, 2%. It is more preferably formed in the range of 70% or more, and further preferably formed in the range of 5% or more and 50% or less. In addition, it may be formed larger than 80% with respect to the thickness t0 of the first conductive layer 20. Others are the same as those in the second embodiment, so the same reference numerals are given and the description thereof will be omitted.

The through hole 251 may have a diameter D2 of the dug recess (recess) 252 on the surface of the first conductive layer 20 smaller than the diameter D1 on the surface of the power generation layer 30, and the through hole 251 may have, for example, a mortar shape. It may be formed in a bowl shape or the like. The same applies hereinafter.

According to the first modification of the second embodiment, the pitch P of the through hole 251 is formed to be larger than the diameter D1 of the through hole 251 and the adjacent through holes 251 are arranged at intervals and dug. Since the diameter D2 of the recess (recess) 252 is smaller than the diameter D1 of the through hole 251, the first conductive layer 20 is not divided, and the conduction on the peripheral surface of the recess (recess) 252 is not divided. Can be secured.

[Second variant (second embodiment)]
Next, a second modification of the second embodiment of the present invention will be described with reference to FIG.
FIG. 10 is a diagram illustrating a schematic configuration of a solar cell according to a second modification of the second embodiment, and FIG. 10A is a view of the arrangement of through-hole rows as viewed from the upper surface (surface) side of the power generation layer. It is a plan view, and FIG. 10B is a vertical cross-sectional view shown by arrow XB-XB in FIG. 10A.

The second modification is different from the second embodiment in that the diameter D2 on the surface of the first conductive layer 20 of the dug recess (recess) 252 in the through hole 251 is smaller than the diameter D1 on the surface of the power generation layer 30. As shown in FIG. 10, the pitch P of the through hole 251 is formed to be 1 times the diameter D1 on the surface of the power generation layer 30 of the through hole 251 and the adjacent through hole 251 is the power generation layer 30. It is a point that is circumscribed on the surface of.

The pitch P of the through hole 251 is formed to be once (twice the radius) the diameter D1 on the surface of the power generation layer 30 of the through hole 251. That is, the pitch P of the through hole 251 is formed to be larger than the diameter D2 on the surface of the first conductive layer 20 of the digging recess (recess) 252. As a result, the adjacent digging recesses (recesses) 252 are arranged with an interval of 21G.

The pitch P of the through hole 251 is formed to be smaller than the diameter D1 on the surface of the power generation layer 30 of the through hole 251 and larger than the diameter D2 on the surface of the first conductive layer 20 of the dug recess (recess) 252 so as to be adjacent to each other. The through holes 251 may be formed so as to overlap on the surface of the power generation layer 30.

According to the second modification of the second embodiment, the pitch P of the through holes 251 is formed to be smaller than the diameter D1 on the surface of the power generation layer 30 of the through holes 251 and the adjacent through holes 251 are arranged so as to overlap each other. However, since the adjacent digging recesses (recesses) 252 are arranged at intervals, the first conductive layer 20 is not divided, and the peripheral surface of the digging recesses (recesses) 252. Conduction can be ensured.

[Third variant (second embodiment)]
Next, a third modification of the second embodiment of the present invention will be described with reference to FIG.
FIG. 11 is a diagram illustrating a schematic configuration of a solar cell according to a third modification of the second embodiment, and FIG. 11A is a view of the arrangement of through-hole rows from the upper surface (surface) side of the power generation layer. It is a plan view, and FIG. 11 (b) is a vertical cross-sectional view shown by arrow XIB-XIB in FIG. 11 (a).

The third modification is different from the second embodiment in that the diameter D2 on the surface of the first conductive layer 20 of the dug recess (recess) 252 is smaller than the diameter D1 on the surface of the power generation layer 30. Point and, as shown in FIG. 11, the pitch P of the through hole 251 is formed to be 1 times the diameter D1 on the surface of the power generation layer 30 of the through hole 251 and the adjacent through hole 251 is externally attached on the surface of the power generation layer 30. The point that the depth t1 of the digging recess (recess) 252 is formed to be 100% with respect to the thickness t0 of the first conductive layer 20 so that the surface of the insulating base material 10 is exposed. be. Others are the same as those in the second embodiment, so the same reference numerals are given and the description thereof will be omitted.

According to the third modification of the second embodiment, the pitch P of the through hole 251 is formed to be 1 times the diameter D1 of the through hole 251 and the adjacent through holes 251 are arranged circumscribed. Since the diameter D2 of the recess (recess) 252 is smaller than the diameter D1 of the through hole 251 so that the first conductive layer 20 is not divided and the surface of the insulating base material 10 is exposed, the through hole 251 Is formed, so that continuity can be ensured on the peripheral surface of the digging recess (recess) 252.

[Fourth Modified Example (Second Embodiment)]
Next, a fourth modification of the second embodiment of the present invention will be described with reference to FIG.
FIG. 12 is a diagram illustrating a schematic configuration of a solar cell according to a fourth modification of the second embodiment, and FIG. 12A is a view of the arrangement of through-hole rows from the upper surface (surface) side of the power generation layer. It is a plan view, and FIG. 12B is a vertical cross-sectional view shown by arrow XIIB-XIIB in FIG. 12A.

The fourth modification is different from the second embodiment in that the diameter D2 on the surface of the first conductive layer 20 of the digging recess (recess) 252 in the through hole 251 is smaller than the diameter D1 on the surface of the power generation layer 30. As shown in FIG. 12, the pitch P of the through hole 251 is formed to be smaller than the diameter D1 on the surface of the power generation layer 30 of the through hole 251 and the adjacent through hole 251 is the power generation layer 30. The points are arranged so as to overlap on the surface (that is, the through holes 251 are provided at a pitch smaller than 1 times the dimension along the arrangement direction of the through holes 251 on the surface of the power generation layer 30). The point is that the depth t1 of the digging recess (recess) 252 is formed to be 100% with respect to the thickness t0 of the first conductive layer 20, and the surface of the insulating base material 10 is exposed. Others are the same as those in the second embodiment, so the same reference numerals are given and the description thereof will be omitted.

As shown in FIG. 12, the pitch P of the through hole 251 is formed to be larger than the diameter D2 on the surface of the first conductive layer 20 of the digging recess (recess) 252.
That is, they are arranged with an interval of 21G between the adjacent digging recesses (recesses) 252.

According to the fourth modification of the second embodiment, the adjacent through holes 251 are arranged so as to overlap each other, and the digging recess (recess) 252 penetrates the first conductive layer 20 and reaches the insulating base material 10. However, since the adjacent digging recesses (recesses) 252 are arranged with an interval of 21G, the first conductive layer 20 is not divided, and the peripheral surface of the digging recesses (recesses) 252. Conduction can be ensured.

[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIG.
FIG. 13 is a perspective view conceptually showing a group of through-hole rows before the formation of the second conductive layer for explaining the schematic configuration of the solar cell according to the third embodiment of the present invention.

As shown in FIG. 13, the solar cell 300 according to the third embodiment includes, for example, an insulating base material 10, a first conductive layer 20, a power generation layer 30, a second conductive layer 40, and a power generation layer 30. It is provided with a through-hole row group 350 that penetrates.
The third embodiment is different from the second embodiment in that it includes a through-hole row group 350 composed of a plurality of rows of through-hole rows 250 having an interval of 30 G formed between adjacent through-holes 251.

The first modification to the fourth modification of the second embodiment may be applied to the third embodiment. Others are the same as those of the second embodiment and the first to fourth modifications thereof, so the same reference numerals are given and the description thereof will be omitted.

The through-hole row group 350 includes two rows (plurality of rows) of through-hole rows 250.
The through hole row group 350 is formed in the overlapping portion 42.
The distance 31G between the two through-hole rows 250 in the through-hole row group 350 can be arbitrarily set, but the distance 31G between the through-hole rows 250 is, for example, 50 μm (twice the radius, the width of the through-hole row). It is set to 1x). It is preferable that the interval 31G of the through-hole rows 250 is set to 1 times or more and 2 times (1 times the width of the through-hole rows) or less with respect to the diameter D1 of the through-holes 251 constituting the through-hole row 250.

The same configuration as the first modification to the fourth modification of the second embodiment may be applied to the arrangement of the through hole rows 250 in the third embodiment. That is, the through-hole rows 250 may be circumscribed on the surface of the power generation layer 30, or may be arranged so as to overlap.

The through-hole row group 350 can be formed by, for example, irradiating a laser beam emitted from a laser transmitting device (not shown) twice (multiple times). Further, the laser irradiation heads may be arranged in parallel as many as the number of through-hole rows to irradiate.

According to the solar cell 300 according to the third embodiment, since the through-hole rows 250 are provided with the through-hole row groups 350 arranged in a plurality of rows, the conduction area between the first conductive layer 20 and the second conductive layer 40 is increased. This makes it possible to make the conduction between the first conductive layer 20 and the second conductive layer 40 more stable.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the invention.

For example, in the above embodiment, the case where the solar cell (solid-state junction type photoelectric conversion element) includes a perovskite layer (light absorption layer) as the power generation layer 30 has been described, but the light absorption layer is limited to the perovskite layer. It may be set arbitrarily.

Further, in the above embodiment, the through holes 251 constituting the through hole row 250 are formed in a range in which the depth t1 of the digging recess 252 is less than 80% with respect to the thickness t0 of the first conductive layer 20. Although the case has been described, the depth t1 of the digging recess 252 with respect to the thickness t0 of the first conductive layer 20 can be arbitrarily set. For example, the digging recess 252 may be formed in a range larger than 80% with respect to the thickness t0 of the first conductive layer 20.

Further, in the above embodiment, when a plurality of through

holes

51 and 251 form through

hole rows

50 and 250 and the through

holes

51 and 251 are arranged linearly in a plan view in the plane direction of the power generation layer 30. As described above, the arrangement (plan view) of the plurality of through

holes

51 and 251 in the plane direction of the power generation layer 30 may be arbitrarily set. For example, the plurality of through

holes

51 and 251 may be set in the plane direction of the power generation layer 30. It may be arranged along the plan view curve.
Further, instead of the through-hole row 250 according to the third embodiment, the through-hole row 50 may be arranged, or the through-hole row 250 and the through-hole row 50 may be arranged in combination.
Further, the plurality of through

holes

51 and 251 may be arranged in a staggered shape or any other form, for example.

In the above embodiment, the case where the through

holes

51 and 251 are formed in a substantially circular shape in a plan view has been described. good. Further, in the case of an elliptical shape in a plan view, it is possible to arbitrarily set whether the through

holes

51 and 251 are arranged along the long axis, along the short axis, or along other directions. Can be done. When the through

holes

51 and 251 have an elliptical shape, the pitch of the through

holes

51 and 251 can be set based on the semi-major axis or the short radius of the elliptical shape of the recess.

In the above embodiment, the case where the through hole 251 is provided with the recessed recess 252 formed in a substantially circular shape in a plan view has been described. The digging recess 252 may be provided. Further, when the digging recess 252 has an elliptical shape in a plan view, whether the through holes 251 are arranged along the long axis, along the short axis, or along another direction. You can set it as you like.

Further, in the above embodiment, the case where the through

holes

51 and 251 are formed with a apparent diameter of φ50 μm and a pitch P of 50 μm has been described, but the diameter D1 and the pitch P of the through holes 51 can be arbitrarily set. ..

Further, in the above embodiment, the case where the through hole 51 is formed in a cylindrical shape and the through hole 251 is formed in a cylindrical shape or a multi-stage cylindrical shape has been described, but the shapes of the through

holes

51 and 251 are arbitrarily set. It is possible to do. For example, it may be formed in a mortar shape, a bowl shape, or another shape.

Further, in the third embodiment, the case where the through-hole row group 350 includes two rows (plurality of rows) of through-hole rows 250 has been described. For example, the through-hole row group 350 has three or more rows of through-hole rows 250. It may be a provided configuration.
Further, the through-hole row group may be configured to include a plurality of through-hole rows 50, or may be a configuration in which the through-hole row 50 and the through-hole row 250 are combined.

Further, in the third embodiment, the case where the through-hole row group 340 includes the through-hole rows 250 arranged in parallel with each other in the plane direction of the power generation layer 30 has been described, but a plurality of through-hole rows 250 (50). ) Is provided, the arrangement direction of the through holes 251 (51) may be arbitrarily set. For example, the arrangement of the through holes 251 (51) may be arranged so as to be close to or separated from each other in any one of the arrangement directions, or partially close to or separated from each other in any one (range) of the arrangement directions. ..

In addition, it is possible to replace the components in the above-described embodiment with well-known components as appropriate without departing from the spirit of the present invention, and the above-described embodiments may be appropriately combined and applied. For example, in addition to the through-hole row 50, a conductive path other than the through-hole row 50 may be provided.

According to the present invention, stable conduction between the first conductive layer and the second conductive layer can be ensured. Can be done. Therefore, it has high industrial applicability.

10 Insulating base material 20 First conductive layer 30 Power generation layer 40 Second

conductive layer

50, 250 Through

hole rows

51, 251 Through holes 252 Excavation recesses (recesses, ends)
350 through-

hole row group

100, 200, 300 Solar cells

Claims

A plurality of first conductive layers spaced apart from each other on one surface of the insulating substrate.
A power generation layer arranged so as to cover the surfaces of the plurality of first conductive layers and including a photoelectric conversion layer, and a power generation layer.
A plurality of second conductive layers provided on the surface side of the power generation layer at intervals facing each other of the first conductive layers, when viewed from a direction perpendicular to the surface of the power generation layer. A plurality of second conductive layers arranged with overlapping portions overlapping with the first conductive layer adjacent to the first conductive layer facing each other.
A plurality of through holes are provided in the overlapping portion so as to be arranged along the surface direction of the power generation layer and penetrate the power generation layer in the thickness direction.
The through hole reaches a position beyond the boundary between the power generation layer and the first conductive layer.
A solar cell in which a plurality of the second conductive layers are sequentially electrically connected through the through holes communicating with the first conductive layer adjacent to the first conductive layer facing each other.
The solar cell according to claim 1.
One end of the through hole is a solar cell arranged inside the first conductive layer.
The solar cell according to claim 1 or 2.
A solar cell having a recessed recess in the first conductive layer at one end of the through hole.
The solar cell according to claim 3.
A solar cell in which the through holes are formed at a pitch larger than 1 times the dimension along the arrangement direction of the recesses on the surface of the first conductive layer.
The solar cell according to claim 3.
A solar cell in which the through holes are formed at a pitch of 1 times or less the dimension along the arrangement direction of the recesses on the surface of the first conductive layer.
The solar cell according to claim 4.
The concave portion has a circular shape on the surface of the first conductive layer in a plan view, or an elliptical shape having a major axis or a minor axis along the arrangement direction.
A solar cell in which the through holes are provided at a pitch larger than twice the circular radius of the recess or the semi-major axis or semi-minor axis of the elliptical shape.
The solar cell according to any one of claims 3 to 6.
A solar cell in which the depth of the recess is in the range of less than 80% with respect to the thickness of the first conductive layer.
The solar cell according to any one of claims 3 to 6.
A solar cell in which the depth of the recess is 100% with respect to the thickness of the first conductive layer.
The solar cell according to any one of claims 1 to 8.
A solar cell in which the through holes are provided at a pitch of one or more times the dimension along the arrangement direction of the through holes on the surface of the power generation layer.
The solar cell according to any one of claims 1 to 8.
A solar cell in which the through holes are provided at a pitch smaller than 1 times the dimension along the arrangement direction of the through holes on the surface of the power generation layer.
The solar cell according to any one of claims 1 to 10.
The through hole has a circular shape on the surface of the power generation layer in a plan view or an elliptical shape having a major axis or a minor axis along the arrangement direction of the through hole, and the through hole has a radius of the circular shape or A solar cell provided at a pitch of twice or more the semi-major axis or the semi-minor axis of the elliptical shape.
The solar cell according to any one of claims 1 to 11.
The through holes are solar cells arranged in a plurality of rows.
The first conductive layer and
A power generation layer including a photoelectric conversion layer and
A method for manufacturing a solar cell, which comprises a conductive material including a second conductive layer in this order.
A first step of forming the first conductive layer and the power generation layer on one surface of the base material in this order.
A boundary between the power generation layer and the first conductive layer is formed through a plurality of through holes arranged along the surface direction of the power generation layer using a pulse laser and penetrating the power generation layer in the thickness direction. The second step of forming up to the position beyond
A third step of forming the second conductive layer on the power generation layer with the conductive material, and
A method of manufacturing a solar cell.
The method for manufacturing a solar cell according to claim 13.
In the second step,
A method for manufacturing a solar cell, in which one end of the through hole is formed inside the first conductive layer.
The method for manufacturing a solar cell according to claim 14.
In the second step,
A method for manufacturing a solar cell, in which the through hole having a recessed recess in the first conductive layer is formed at the end portion.
The method for manufacturing a solar cell according to claim 15.
In the second step,
A method for manufacturing a solar cell, in which the through holes are formed at a pitch larger than 1 times the dimension along the arrangement direction of the recesses on the surface of the first conductive layer.
The method for manufacturing a solar cell according to claim 16.
In the second step,
Plan view A through hole having the recess formed in an elliptical shape having a circular shape on the surface of the first conductive layer or an elliptical shape having a major axis or a minor axis along the arrangement direction is formed by forming a circular radius of the recess or the circular radius of the recess. A method for manufacturing a solar cell, which is formed with a pitch larger than twice the semi-major axis or the semi-minor axis of an elliptical shape.
The method for manufacturing a solar cell according to any one of claims 15 to 17.
A method for manufacturing a solar cell, wherein the depth of the recess is formed in a range of less than 80% with respect to the thickness of the first conductive layer.
The method for manufacturing a solar cell according to any one of claims 13 to 18.
What
In the second step,
A method for manufacturing a solar cell, in which the through holes are formed at a pitch of one or more times the dimension along the arrangement direction of the through holes on the surface of the power generation layer.
The method for manufacturing a solar cell according to any one of claims 13 to 19.
In the second step,
Plan view The through hole formed in an elliptical shape having a circular shape on the surface of the power generation layer or an elliptical shape having a major axis or a minor axis along the arrangement direction of the through hole is formed by the radius of the circular shape or the elliptical shape. A method for manufacturing a solar cell, which is formed at a pitch of twice or more a semi-major axis or a semi-minor axis.
The method for manufacturing a solar cell according to any one of claims 13 to 20.
In the second step,
A method for manufacturing a solar cell, in which the through holes are formed in a plurality of rows.