Thin-film solar cell structure and preparation method thereof

文档序号：345144 发布日期：2021-12-03 浏览：15次中文

阅读说明：本技术 一种薄膜太阳能电池结构及其制备方法 (Thin-film solar cell structure and preparation method thereof ) 是由董超赵志国秦校军李新连李梦洁赵东明熊继光张赟黄斌李芳富冯笑丹于 2021-10-11 设计创作，主要内容包括：本申请公开了一种薄膜太阳能电池结构及其制备方法,相对于现有薄膜太阳能电池结构,通过子电池两侧沿第一方向依次排布的P1、P2、P3三个刻线槽实现相邻子电池的串联连接,该薄膜太阳能电池结构,将相邻子电池的串联连接部分转移到子电池沿第二方向的一端或两端,第二方向与第一方向垂直,使得相邻子电池之间的死区部分只有一种刻线槽,相当于现有技术中相邻子电池之间沿第二方向延伸的P1、P2、P3三个刻线槽重合,即去除了现有技术中相邻子电池之间的两种刻线槽以及相邻刻线槽之间的间距,从而大大减小薄膜太阳能电池的死区面积,增加薄膜太阳能电池的受光面积,提高薄膜太阳能电池的转换效率。(The application discloses a thin-film solar cell structure and a preparation method thereof, and compared with the existing thin-film solar cell structure, the series connection of adjacent sub-cells is realized through three scribing grooves of P1, P2 and P3 which are sequentially arranged along a first direction on two sides of the sub-cells, the thin-film solar cell structure transfers the series connection part of the adjacent sub-cells to one end or two ends of the sub-cells along a second direction, the second direction is vertical to the first direction, so that the dead zone part between the adjacent sub-cells is only provided with one scribing groove, which is equivalent to the superposition of three scribing grooves of P1, P2 and P3 which extend along the second direction between the adjacent sub-cells in the prior art, namely two scribing grooves between the adjacent sub-cells and the distance between the adjacent scribing grooves in the prior art are removed, thereby greatly reducing the dead zone area of the thin-film solar cell and increasing the light receiving area of the thin-film solar cell, the conversion efficiency of the thin film solar cell is improved.)

1. A thin film solar cell structure, comprising:

a substrate;

at least one battery assembly located on the surface of the substrate, wherein the battery assembly comprises M sub-batteries arranged at intervals in sequence along a first direction, and the first direction is parallel to the surface of the substrate;

each sub-cell comprises a lower electrode, an active layer and an upper electrode which are sequentially arranged along a direction departing from the substrate, the lower electrode of each sub-cell is provided with a first end and a second end which are opposite along a second direction, the upper electrode is provided with a third end and a fourth end which are opposite along the second direction, and the second direction is parallel to the surface of the substrate and is vertical to the first direction;

the first end of the lower electrode of the ith sub-battery is connected with the third end of the upper electrode of the (i-1) th sub-battery, the third end of the upper electrode of the ith sub-battery is connected with the first end of the lower electrode of the (i + 1) th sub-battery, and i is more than or equal to 2 and less than or equal to M-1.

2. The thin-film solar cell structure of claim 1, wherein the lower electrodes of the ith and Mth sub-cells comprise a first lower electrode extending along the second direction, and a second lower electrode extending from one end of the first lower electrode to a third direction, the second lower electrode being a first end of the lower electrode, one end of the first lower electrode facing away from the second lower electrode being a second end of the lower electrode, and the third direction being parallel to the substrate surface and intersecting the second direction;

the upper electrodes of the ith sub-battery and the 1 st sub-battery comprise a first upper electrode extending along the second direction and a second upper electrode extending from one end of the first upper electrode to a fourth direction, the second upper electrode is the third end of the upper electrode, one end of the first upper electrode departing from the second upper electrode is the fourth end of the upper electrode, and the fourth direction is parallel to the surface of the substrate and intersects with the second direction;

and the second lower electrode of the ith sub-battery is at least partially contacted with the second upper electrode of the (i-1) th sub-battery, and the second upper electrode of the ith sub-battery is at least partially contacted with the second lower electrode of the (i + 1) th sub-battery.

3. The thin-film solar cell structure of claim 2, wherein the third direction and the fourth direction are both perpendicular to the second direction, and the third direction and the fourth direction are anti-parallel.

4. The thin-film solar cell structure of claim 3, wherein the first end of the lower electrode of each sub-cell and the third end of the upper electrode thereof are located on opposite sides of the cell assembly in the second direction, and the first end of the lower electrode of the i-th sub-cell and the second end of the lower electrode of the i-1 th sub-cell, and the second ends of the lower electrodes of the i +1 th sub-cells are located on the same side of the cell assembly in the second direction;

in the second direction, the projection of the first lower electrode of the ith sub-cell is at least partially located in the projection range of the second lower electrode of the (i + 1) th sub-cell, and the projection of the first upper electrode of the ith sub-cell is at least partially located in the projection range of the second upper electrode of the (i-1) th sub-cell.

5. The thin-film solar cell structure according to claim 4, wherein the lower electrode of the 1 st sub-cell extends along the second direction, and a projection of the lower electrode of the 1 st sub-cell in the second direction is at least partially within a projection range of the second lower electrode of the 2 nd sub-cell;

the upper electrode of the Mth sub-cell extends along the second direction, and in the second direction, the upper electrode of the Mth sub-cell is at least partially located within the projection range of the second upper electrode of the M-1 th sub-cell.

6. The thin film solar cell structure of claim 1, wherein the at least one cell module comprises a plurality of cell modules, the cell modules further comprising: the battery pack comprises a lower connecting electrode and an upper connecting electrode, wherein the lower connecting electrode and the upper connecting electrode are used for connecting the battery pack to which the battery pack belongs in series with an adjacent battery pack or are used as output electrodes of the battery pack to which the battery pack belongs.

7. The thin-film solar cell structure of claim 6, wherein the lower connection electrode is located at the second end of the lower electrode of the Mth sub-cell and at least partially contacts the third end of the upper electrode of the Mth sub-cell;

the upper connecting electrode is positioned at the fourth end of the upper electrode of the 1 st sub-cell and is at least partially contacted with the first end of the lower electrode of the 1 st sub-cell.

8. The thin film solar cell structure of any of claims 1-7, wherein the active layer of each subcell comprises a first charge transport layer, a perovskite light absorbing layer, and a second charge transport layer arranged in sequence in a direction away from the substrate, each subcell further comprising: and the isolation layer is positioned at two opposite ends of the active layer along the second direction and is used for isolating the active layer from contacting with the upper electrode at the two opposite ends of the active layer along the second direction.

9. The thin-film solar cell structure of claim 8, wherein the isolation layer is a metallic bismuth layer or a silicon nitride layer.

10. A method for preparing a thin film solar cell structure is characterized by comprising the following steps:

providing a substrate;

forming at least one battery assembly on the surface of the substrate, wherein the battery assembly comprises M sub-batteries which are sequentially arranged at intervals along a first direction, each sub-battery comprises a lower electrode, an active layer and an upper electrode which are sequentially arranged along a direction departing from the substrate, and the first direction is parallel to the surface of the substrate;

the formation process of the battery assembly includes:

forming a lower electrode layer on the surface of the substrate;

carrying out first laser scribing on the lower electrode layer, wherein the first laser scribing at least comprises a laser scribing along a second direction, so that the lower electrode layer is divided into lower electrodes of sub-cells, the lower electrode of each sub-cell is provided with a first end and a second end which are opposite along the second direction, and the second direction is parallel to the surface of the substrate and is vertical to the first direction;

forming an active layer on the lower electrode of each sub-cell;

performing second laser scribing on the active layer, wherein the second laser scribing is overlapped with the laser scribing along the second direction in the first laser scribing, so that the active layer is divided into active layers of the sub-batteries;

forming an upper electrode layer on the active layer of each sub-cell;

carrying out third laser scribing on the upper electrode layer, so that the upper electrode layer is divided into upper electrodes of the sub-cells, and the upper electrode of each sub-cell is provided with a third end and a fourth end which are opposite to each other along the second direction;

11. The method of claim 10, wherein the first laser scribe further comprises a laser scribe along a third direction, the third direction being parallel to the substrate surface and intersecting the second direction, such that the lower electrodes of the ith and mth subcells comprise a first lower electrode extending along the second direction and a second lower electrode extending from one end of the first lower electrode to the third direction, the second lower electrode being a first end of the lower electrode, the end of the first lower electrode facing away from the second lower electrode being a second end of the lower electrode;

the third laser scribing line comprises a laser scribing line along a fourth direction, the fourth direction is parallel to the substrate surface and intersects with the second direction, so that the upper electrodes of the ith sub-cell and the 1 st sub-cell comprise a first upper electrode extending along the second direction and a second upper electrode extending from one end of the first upper electrode to the fourth direction, the second upper electrode is a third end of the upper electrode, and one end of the first upper electrode, which is far away from the second upper electrode, is a fourth end of the upper electrode;

12. The method of claim 10, wherein the at least one cell assembly comprises a plurality of cell assemblies, and wherein, when the lower electrode layer is first laser scribed to divide the lower electrode layer into the lower electrodes of the sub-cells, the method further comprises:

dividing a lower connecting electrode in the lower electrode layer by utilizing the first laser scribing line;

when the third laser scribing is performed on the upper electrode layer, so that the upper electrode layer is divided into the upper electrodes of the sub-cells, the method further comprises the following steps:

dividing an upper connecting electrode in the upper electrode layer by using the third laser scribing line;

the lower connecting electrode and the upper connecting electrode are used for connecting the battery component to which the lower connecting electrode and the upper connecting electrode belong in series with the adjacent battery component or are used as output electrodes of the battery components to which the lower connecting electrode and the upper connecting electrode belong.

13. The method according to any one of claims 10 to 12, wherein the active layer comprises a first charge transport layer, a perovskite light absorbing layer and a second charge transport layer arranged in that order in a direction away from the substrate, and the process of forming the active layer on the lower electrode of each sub-cell comprises:

shielding the first end and the second end of the lower electrode of each sub-battery;

forming the first charge transmission layer on the other parts of the lower electrode of each sub-battery except the shielded part, and removing shielding of the first end and the second end of the lower electrode of each sub-battery;

forming the perovskite light absorption layer on the first charge transport layer;

laser edge cleaning is carried out on the parts, corresponding to the first end and the second end of the lower electrode of each sub-cell, of the perovskite light absorption layer;

shielding the first end and the second end of the lower electrode of each sub-battery again;

and forming the second charge transport layer on the perovskite light absorption layer, and removing the shielding of the first end and the second end of the lower electrode of each sub-cell.

14. The method of claim 13, further comprising, prior to forming the upper electrode layer on the active layer of each sub-cell:

forming isolation layers at two opposite ends of the active layer of each sub-battery along the second direction; for any of the subcells, the isolation layer is for isolating the active layer from contact with the upper electrode at its two ends opposite along the second direction.

15. The method of claim 10, wherein forming an upper electrode layer on the active layer of each sub-cell comprises:

Technical Field

The application relates to the technical field of photovoltaic power generation, in particular to a thin-film solar cell structure and a preparation method thereof.

Background

The thin-film solar cell is thin as the name suggests, so that the cost is easier to reduce, and meanwhile, the thin-film solar cell is a high-efficiency energy product, is a novel building material, and is easier to perfectly combine with a building, so that the thin-film solar cell becomes a new trend and a new hot spot for the development of a photovoltaic market.

In the existing thin-film solar cell, laser scribes of P1, P2 and P3 are usually performed on both sides of each sub-cell in sequence to realize the series connection of adjacent sub-cells, however, such laser scribes inevitably generate dead zones between adjacent sub-cells, the dead zone part between adjacent sub-cells includes the regions from the P1 scribe groove to the P3 scribe groove, i.e., the three scribe grooves of P1, P2 and P3, the spacing between the P1 scribe groove and the P2 scribe groove, and the spacing between the P2 scribe groove and the P3 scribe groove, and since no active layer is in the dead zone or the positive and negative electrodes of the active layer in the dead zone are shorted, the dead zone part cannot output power, thereby affecting the conversion efficiency of the solar thin-film cell. How to reduce the dead zone area of the thin film solar cell becomes a technical problem to be solved urgently by the technical personnel in the field.

Disclosure of Invention

In order to solve the technical problem, embodiments of the present application provide a thin film solar cell structure and a manufacturing method thereof, so as to reduce a dead zone area of the thin film solar cell and improve conversion efficiency of the thin film solar cell.

In order to achieve the above object, the embodiments of the present application provide the following technical solutions:

a thin film solar cell structure comprising:

a substrate;

Optionally, the lower electrodes of the ith and mth sub-cells include a first lower electrode extending along the second direction, and a second lower electrode extending from one end of the first lower electrode to a third direction, where the second lower electrode is a first end of the lower electrode, one end of the first lower electrode facing away from the second lower electrode is a second end of the lower electrode, and the third direction is parallel to the substrate surface and intersects with the second direction;

Optionally, the third direction and the fourth direction are both perpendicular to the second direction, and the third direction and the fourth direction are antiparallel.

Optionally, the first end of the lower electrode of each sub-cell and the third end of the upper electrode of each sub-cell are located on opposite sides of the cell assembly in the second direction, and the first end of the lower electrode of the ith sub-cell and the second end of the lower electrode of the (i-1) th sub-cell, and the second end of the lower electrode of the (i + 1) th sub-cell are located on the same side of the cell assembly in the second direction;

Optionally, the lower electrode of the 1 st sub-cell extends along the second direction, and in the second direction, a projection of the lower electrode of the 1 st sub-cell is at least partially located within a projection range of the second lower electrode of the 2 nd sub-cell;

Optionally, the at least one battery assembly includes a plurality of battery assemblies, and the battery assembly further includes: the battery pack comprises a lower connecting electrode and an upper connecting electrode, wherein the lower connecting electrode and the upper connecting electrode are used for connecting the battery pack to which the battery pack belongs in series with an adjacent battery pack or are used as output electrodes of the battery pack to which the battery pack belongs.

Optionally, the lower connection electrode is located at the second end of the lower electrode of the mth sub-cell and at least partially contacts the third end of the upper electrode of the mth sub-cell;

Optionally, the active layer of each sub-cell includes a first charge transport layer, a perovskite light absorption layer, and a second charge transport layer sequentially arranged along a direction away from the substrate, and each sub-cell further includes: and the isolation layer is positioned at two opposite ends of the active layer along the second direction and is used for isolating the active layer from contacting with the upper electrode at the two opposite ends of the active layer along the second direction.

Optionally, the isolation layer is a metal bismuth layer or a silicon nitride layer.

A method for preparing a thin film solar cell structure comprises the following steps:

providing a substrate;

the formation process of the battery assembly includes:

forming a lower electrode layer on the surface of the substrate;

forming an active layer on the lower electrode of each sub-cell;

forming an upper electrode layer on the active layer of each sub-cell;

Optionally, the first laser scribe further includes a laser scribe along a third direction, where the third direction is parallel to the substrate surface and intersects with the second direction, so that the lower electrodes of the ith and mth sub-cells include a first lower electrode extending along the second direction and a second lower electrode extending from one end of the first lower electrode to the third direction, where the second lower electrode is a first end of the lower electrode, and one end of the first lower electrode facing away from the second lower electrode is a second end of the lower electrode;

Optionally, the at least one battery assembly includes a plurality of battery assemblies, and when the lower electrode layer is subjected to the first laser scribing, so as to divide the lower electrode layer into the lower electrodes of the sub-cells, the method further includes:

dividing a lower connecting electrode in the lower electrode layer by utilizing the first laser scribing line;

dividing an upper connecting electrode in the upper electrode layer by using the third laser scribing line;

Optionally, the active layer includes a first charge transport layer, a perovskite light absorption layer, and a second charge transport layer sequentially arranged in a direction away from the substrate, and the process of forming the active layer on the lower electrode of each sub-cell includes:

shielding the first end and the second end of the lower electrode of each sub-battery;

forming the perovskite light absorption layer on the first charge transport layer;

laser edge cleaning is carried out on the parts, corresponding to the first end and the second end of the lower electrode of each sub-cell, of the perovskite light absorption layer;

shielding the first end and the second end of the lower electrode of each sub-battery again;

and forming the second charge transport layer on the perovskite light absorption layer, and removing the shielding of the first end and the second end of the lower electrode of each sub-cell.

Optionally, before forming the upper electrode layer on the active layer of each sub-cell, the method further includes:

Optionally, the process of forming the upper electrode layer on the active layer of each sub-cell includes:

Compared with the prior art, the technical scheme has the following advantages:

the thin-film solar cell structure that this application embodiment provided includes: a substrate; at least one battery assembly located on the surface of the substrate, wherein the battery assembly comprises M sub-batteries arranged at intervals in sequence along a first direction, and the first direction is parallel to the surface of the substrate; each sub-cell comprises a lower electrode, an active layer and an upper electrode which are sequentially arranged along a direction departing from the substrate, the lower electrode of each sub-cell is provided with a first end and a second end which are opposite along a second direction, the upper electrode is provided with a third end and a fourth end which are opposite along the second direction, and the second direction is parallel to the surface of the substrate and is vertical to the first direction; the first end of the lower electrode of the ith sub-battery is connected with the third end of the upper electrode of the (i-1) th sub-battery, the third end of the upper electrode of the ith sub-battery is connected with the first end of the lower electrode of the (i + 1) th sub-battery, and i is more than or equal to 2 and less than or equal to M-1. It can be seen that, compared to the existing thin film solar cell structure, the series connection of the adjacent sub-cells is realized by three scribe lines P1, P2, and P3 arranged in sequence along the first direction on both sides of the sub-cells, and the thin film solar cell structure connects the series connection parts of the adjacent sub-cells, i.e., the upper electrode and lower electrode connecting portions of the adjacent sub-cells, to one or both ends of the sub-cells in the second direction, so that the dead zone part between the adjacent sub-cells only has one scribing groove, which is equivalent to the superposition of three scribing grooves P1, P2 and P3 extending along the second direction between the adjacent sub-cells in the prior art, namely two types of scribing grooves between adjacent sub-batteries and the space between the adjacent scribing grooves in the prior art are removed, therefore, the dead zone area of the thin-film solar cell is greatly reduced, the light receiving area of the thin-film solar cell is increased, and the conversion efficiency of the thin-film solar cell is improved.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic structural diagram of a conventional thin film solar cell;

fig. 2 is a schematic structural diagram of a cell module in a thin film solar cell structure according to an embodiment of the present disclosure;

FIG. 3 is a schematic diagram showing the arrangement of the lower electrode and the upper electrode of each sub-cell in the cell module shown in FIG. 2;

FIG. 4 is a schematic view of the arrangement of the lower electrodes of the sub-cells in the cell module shown in FIG. 2;

FIG. 5 is a schematic view of the arrangement of the upper electrodes of the sub-cells in the cell module shown in FIG. 2;

FIG. 6 is a schematic diagram showing the arrangement of the lower electrode and the active layer of each sub-cell in the cell module shown in FIG. 2;

FIG. 7 is a schematic longitudinal cross-sectional view of a subcell along direction AA' in the cell assembly of FIG. 2;

FIG. 8 is a schematic view of the arrangement of the separators of the sub-cells in the cell assembly shown in FIG. 2;

fig. 9 is a schematic view of a mask of the upper electrode layer, and a schematic view of an arrangement of the upper electrodes of the sub-cells formed after the third laser scribing is performed on the upper electrode layer formed by using the mask;

fig. 10 is a schematic view of a mask for an isolation layer and an arrangement of isolation layers formed using the mask.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application, but the present application may be practiced in other ways than those described herein, and it will be apparent to those of ordinary skill in the art that the present application is not limited to the specific embodiments disclosed below.

Next, the present application will be described in detail with reference to the drawings, and in the detailed description of the embodiments of the present application, the cross-sectional views illustrating the structure of the device are not enlarged partially according to the general scale for convenience of illustration, and the drawings are only examples, which should not limit the scope of the protection of the present application. In addition, the three-dimensional dimensions of length, width and depth should be included in the actual fabrication.

Fig. 1 shows a schematic structural diagram of a conventional thin-film solar cell, as shown in fig. 1, the conventional thin-film solar cell generally includes a laminated structure composed of a glass substrate 01, a conductive layer 02, a hole transport layer 03, a light absorption layer 04, an electron transport layer 05, and a metal electrode layer 06, which are sequentially arranged from bottom to top, and at present, the laminated structure is generally divided into a plurality of sub-cells by using P1, P2, and P3 laser scribes, as shown in fig. 1, the sub-cell n +1, the sub-cell n +2, and the like, and the series connection of adjacent sub-cells is realized. Specifically, the P1 scribe line grooves penetrate through the hole transport layer 03 and the conductive layer 02 to divide the conductive layer 02 into the lower electrodes of the sub-cells; the P2 scribe line groove penetrates through the active layer consisting of the electron transport layer 05, the light absorbing layer 04 and the hole transport layer 03 to divide the active layer into the active layers of the sub-cells; the P3 scribing grooves penetrate through the lamination layer consisting of the metal electrode layer 06, the electron transport layer 05, the light absorption layer 04 and the hole transport layer 03 to the conductive layer 02 so as to divide the metal electrode layer 06 into the upper electrodes of the sub-cells; the metal electrode layer 06 fills the P2 scribe line, i.e. the metal electrode layer 06 is deposited on the conductive layer 02 through the P2 scribe line, as can be seen from the current flow direction through the P2 scribe line shown in fig. 1, thereby realizing the connection of the upper and lower electrodes of the adjacent sub-cells, i.e. the series connection of the adjacent sub-cells.

As described in the background section, such a laser scribing method inevitably generates dead zones between adjacent sub-cells, and as shown in fig. 1, the dead zone between adjacent sub-cells includes the regions from the P1 scribing groove to the P3 scribing groove, i.e., the three scribing grooves of P1, P2 and P3, the spacing between the P1 scribing groove and the P2 scribing groove, and the spacing between the P2 scribing groove and the P3 scribing groove, and since there is no active layer in the dead zone or the positive and negative electrodes of the active layer in the dead zone are shorted, the dead zone cannot output power, thereby affecting the conversion efficiency of the thin film solar cell. How to reduce the dead zone area of the thin film solar cell becomes a technical problem to be solved urgently by the technical personnel in the field.

In view of this, the present application provides a thin film solar cell structure, including:

a substrate; optionally, the substrate is a glass substrate;

at least one battery assembly 100 on the substrate surface, fig. 2 shows a schematic structural diagram of the battery assembly 100, and as shown in fig. 2, the battery assembly 100 includes M sub-batteries 10 sequentially arranged at intervals along a first direction, where the first direction is parallel to the substrate surface; reference numerals 1, 2, 3, 4, 5 … i-1, i +1 … M-1, M in fig. 2 denote the sequence of the sub-batteries 10 in the battery assembly 100 along the first direction, it should be noted that the present application does not limit the number of the sub-batteries 10 included in the battery assembly 100, and fig. 2 only illustrates a case where the battery assembly 100 includes more than 5 sub-batteries 10;

as shown in fig. 2, each sub-cell 10 includes a lower electrode 11, an active layer 12, and an upper electrode 13 sequentially arranged in a direction (as shown in a Z direction in fig. 2) away from the substrate, and the lower electrode 11 of each sub-cell has a first end and a second end opposite to each other along a second direction, and the upper electrode 13 has a third end and a fourth end opposite to each other along the second direction, and the second direction is parallel to the substrate surface and perpendicular to the first direction; optionally, the lower electrode 11 of each sub-cell 10 is a transparent electrode, and the upper electrode 13 is a metal electrode.

In order to more clearly show the arrangement of the lower electrode 11 and the upper electrode 13 of each sub-cell 10, fig. 3 shows a schematic diagram of the arrangement of the lower electrode 11 and the upper electrode 13 of each sub-cell 10 in the cell assembly shown in fig. 2, as shown in fig. 3, for any sub-cell, the lower electrode 11 has a first end and a second end opposite to each other along the second direction, as shown in the ends (i) and (ii) opposite to each other along the second direction of the lower electrode 11 of any sub-cell in fig. 3, the upper electrode 13 has a third end and a fourth end opposite to each other along the second direction, as shown in the ends (iii) and (iv) opposite to each other along the second direction of the upper electrode 13 of any sub-cell in fig. 3;

wherein, the first end of the lower electrode 11 of the ith sub-battery (shown as the (r) end of the lower electrode 11 of the ith sub-battery in fig. 3) is connected with the third end of the upper electrode 13 of the (i-1) th sub-battery (shown as the (r) end of the upper electrode 13 of the (i-1) th sub-battery in fig. 3), the third end of the upper electrode 13 of the ith sub-battery (shown as the (r) end of the upper electrode 13 of the ith sub-battery in fig. 3) is connected with the first end of the lower electrode 11 of the (i + 1) th sub-battery (shown as the (r) end of the lower electrode 11 of the (i + 1) th sub-battery in fig. 3), and i is more than or equal to 2 and less than or equal to M-1. It should be noted that i can be any integer between 2 and M-1.

Specifically, a series connection mode of three sub-cells randomly and continuously arranged in the first direction in the thin-film solar cell structure provided in the embodiment of the present application will be described by taking the 1 st sub-cell, the 2 nd sub-cell, and the 3 rd sub-cell in fig. 2 and 3 as examples.

As shown in fig. 2 and 3, the lower electrodes 11 of the 1 st sub-cell, the 2 nd sub-cell and the 3 rd sub-cell all extend along the second direction, and have a first end (shown as the end (r) in fig. 3) and a second end (shown as the end (r) in fig. 3) opposite to each other in the second direction; the upper electrodes 13 of the 1 st, 2 nd and 3 rd sub-cells all extend along the second direction, and have a third end (shown as the third end in fig. 3) and a fourth end (shown as the fourth end in fig. 3) opposite to each other in the second direction, wherein the first end (shown as the first end in fig. 3) of the lower electrode of the 2 nd sub-cell is connected to the third end (shown as the third end in fig. 3) of the upper electrode of the 1 st sub-cell, and the third end (shown as the third end in fig. 3) of the upper electrode of the 2 nd sub-cell is connected to the first end (shown as the first end in fig. 3) of the lower electrode of the 3 rd sub-cell.

By analogy, for three sub-batteries randomly and continuously arranged in the first direction, the three sub-batteries are sequentially set as a first sub-battery, a second sub-battery and a third sub-battery, a first end (shown as end r in fig. 3) of the lower electrode of the second sub-battery is connected with a third end (shown as end r in fig. 3) of the upper electrode of the first sub-battery, and a third end (shown as end r in fig. 3) of the upper electrode of the second sub-battery is connected with a first end (shown as end r in fig. 3) of the lower electrode of the third sub-battery, so that the three sub-batteries randomly and continuously arranged in the first direction are connected in series.

It should be noted that, in the present application, the manner of connecting the first end of the lower electrode of the ith sub-battery to the third end of the upper electrode of the (i-1) th sub-battery and connecting the third end of the upper electrode of the ith sub-battery to the first end of the lower electrode of the (i + 1) th sub-battery is not limited, and the connection may be direct contact as shown in fig. 2 and 3, that is, the lower electrode of the ith sub-battery is connected to the portion of the upper electrode of the (i-1) th sub-battery extending toward the ith sub-battery through the portion thereof extending toward the (i + 1) th sub-battery, and the connection may be direct contact or indirect contact through another conductor, as long as the upper and lower electrodes of adjacent sub-cells are connected by one or both ends thereof in the second direction.

Since the connection manner of the upper electrode and the lower electrode of the adjacent sub-batteries is not limited in the present application, and may be direct contact or indirect contact, the present application does not limit the specific shape of the upper electrode and the lower electrode of each sub-battery, and may be as shown in fig. 2 and fig. 3, that is, except that the lower electrode of the 1 st sub-battery and the upper electrode of the M-th sub-battery are strip-shaped, the upper electrode and the lower electrode of each sub-battery are both L-shaped, or the upper electrode and the lower electrode of each sub-battery are both strip-shaped or L-shaped, or even other shapes, as long as the upper electrode and the lower electrode of the adjacent sub-battery are connected through one or both ends thereof along the second direction.

It should be noted that, for any sub-cell, the first end of the lower electrode and the third end of the upper electrode thereof may be located on opposite sides of the cell assembly in the second direction, that is, the first end of the lower electrode and the fourth end of the upper electrode thereof are located on the same side of the cell assembly in the second direction, as shown in fig. 3, in this case, the connection of the first end of the lower electrode of the i-th sub-cell and the connection of the third end of the upper electrode of the i-th sub-cell and the first end of the lower electrode of the i + 1-th sub-cell are located on opposite sides of the cell assembly in the second direction, that is, the end of the i-th sub-cell in the second direction, and the lower electrode thereof is connected to the upper electrode of the i-1-th sub-cell, and at the other end thereof in the second direction, the upper electrode of the first sub-battery is connected with the lower electrode of the (i + 1) th sub-battery;

for any sub-battery, the first end of the lower electrode and the third end of the upper electrode of the sub-battery may also be located on the same side of the battery assembly in the second direction, and at this time, the first end of the lower electrode of the ith sub-battery is connected to the third end of the upper electrode of the i-th sub-battery, and the third end of the upper electrode of the ith sub-battery is connected to the first end of the lower electrode of the i +1 th sub-battery, which are located on the same side of the battery assembly in the second direction, that is, the end of the ith sub-battery along the second direction, and the lower electrode of the ith sub-battery is connected to the upper electrode of the i-1 th sub-battery, and the upper electrode of the ith sub-battery is connected to the lower electrode of the i +1 th sub-battery; however, the present application is not limited thereto, as the case may be.

It should be further noted that, for two adjacent sub-batteries, taking the ith sub-battery and the (i + 1) th sub-battery as examples, the first end of the lower electrode of the ith sub-battery and the second end of the lower electrode of the (i + 1) th sub-battery may be located on the same side of the battery assembly in the second direction, as shown in fig. 3, the first end of the lower electrode of the ith sub-battery and the second end of the lower electrode of the (i + 1) th sub-battery may also be located on opposite sides of the battery assembly in the second direction, which is not limited in this application, as the case may be.

As can be seen from the above description, fig. 2 only illustrates a schematic structural diagram of the cell module 100, and in the thin film solar cell structure provided in the embodiment of the present application, the structure of the cell module 100 is not limited thereto, as long as in the cell module, the sub-cells are sequentially arranged at intervals along the first direction, and each sub-cell is connected in series with the adjacent sub-cell through one or both ends of the upper electrode and the lower electrode along the second direction.

It can be seen that, compared to the existing thin film solar cell structure, the series connection of the adjacent sub-cells is realized by three scribe lines P1, P2, and P3 arranged in sequence along the first direction on both sides of the sub-cells, and the thin film solar cell structure connects the series connection parts of the adjacent sub-cells, i.e., the upper electrode and lower electrode connecting portions of the adjacent sub-cells, to one or both ends of the sub-cells in the second direction, so that the dead zone part between the adjacent sub-cells only has one scribing groove, which is equivalent to the superposition of three scribing grooves P1, P2 and P3 extending along the second direction between the adjacent sub-cells in the prior art, namely two types of scribing grooves between adjacent sub-batteries and the space between the adjacent scribing grooves in the prior art are removed, therefore, the dead zone area of the thin-film solar cell is greatly reduced, the light receiving area of the thin-film solar cell is increased, and the conversion efficiency of the thin-film solar cell is improved.

On the basis of the above embodiments, as shown in fig. 4, in an embodiment of the present application, fig. 4 shows a schematic layout of the lower electrodes 11 of the sub-cells 10 in the cell assembly shown in fig. 2, and it can be seen that the lower electrodes 11 of the i-th sub-cell (i is 2 ≦ i ≦ M-1) and the M-th sub-cell include a first lower electrode 111 extending along the second direction and a second lower electrode 112 extending from one end of the first lower electrode 111 to a third direction, where the second lower electrode 112 is a first end of the lower electrode 11, one end of the first lower electrode 111 facing away from the second lower electrode 112 is a second end of the lower electrode 11, and the third direction is parallel to the substrate surface and intersects with the second direction;

as shown in fig. 5, fig. 5 shows a schematic layout of the upper electrodes 13 of the sub-cells 10 in the cell module shown in fig. 2, and it can be seen that the upper electrodes 13 of the ith sub-cell (i is 2 ≦ i ≦ M-1) and the 1 st sub-cell include a first upper electrode 131 extending along the second direction, and a second upper electrode 132 extending from one end of the first upper electrode 131 to a fourth direction, where the second upper electrode 132 is a third end of the upper electrode 13, one end of the first upper electrode 131 facing away from the second upper electrode 132 is a fourth end of the upper electrode 13, and the fourth direction is parallel to the substrate surface and intersects with the second direction;

wherein the second lower electrode 112 of the ith sub-cell is at least partially in contact with the second upper electrode 132 of the (i-1) th sub-cell, and the second upper electrode 132 of the ith sub-cell is at least partially in contact with the second lower electrode 112 of the (i + 1) th sub-cell.

As can be seen, in this embodiment, as shown in fig. 2 to 5, for the ith sub-cell, the first lower electrode 111, the active layer 12 and the first upper electrode 131 are sequentially arranged in a direction away from the substrate surface, and are used as the main part of the sub-cell for generating electricity; the second lower electrode 112 of the sub-cell is at least partially contacted with the second upper electrode 132 of the (i-1) th sub-cell, so that the (i) th sub-cell is connected with the (i-1) th sub-cell in series, and the second upper electrode 132 of the sub-cell is at least partially contacted with the second lower electrode 112 of the (i + 1) th sub-cell, so that the (i) th sub-cell is connected with the (i + 1) th sub-cell in series, namely, the second lower electrode 112 and the second upper electrode 132 of the sub-cell are used as the series part of the sub-cell and the adjacent sub-cell.

In addition, in this embodiment, the part of the ith sub-cell extending toward the third direction through the lower electrode 11 (the second lower electrode 112) contacts the part of the ith-1 st sub-cell extending toward the fourth direction (the second upper electrode 132), and the part of the ith sub-cell extending toward the fourth direction through the upper electrode 13 (the second upper electrode 132) contacts the part of the ith +1 st sub-cell extending toward the third direction (the second lower electrode 112), that is, the part of the ith sub-cell extending toward the adjacent sub-cell through the lower electrode 11 or the upper electrode 13 is connected in series with the adjacent sub-cell.

On the basis of the above embodiment, optionally, in an embodiment of the present application, as shown in fig. 4 and 5, the third direction and the fourth direction are both perpendicular to the second direction, and the third direction and the fourth direction are antiparallel. Since the second lower electrode 112 of the ith sub-cell is at least partially in contact with the second upper electrode 132 of the (i-1) th sub-cell, the second upper electrode 132 of the ith sub-cell is at least partially in contact with the second lower electrode 112 of the (i + 1) th sub-cell, and the sub-cells are arranged along the first direction, the third direction is anti-parallel to the first direction, and the fourth direction is parallel to the first direction, that is, for the ith sub-cell, the second lower electrode 112 extends from one end of the first lower electrode 111 to the position close to the (i-1) th sub-cell, and the second upper electrode 132 extends from one end of the first upper electrode 131 to the position close to the (i + 1) th sub-cell.

It should be noted that, in the above embodiment, as shown in fig. 2 to fig. 5, the projection of the second lower electrode 112 of the ith sub-cell and the projection of the second upper electrode 132 of the ith-1 sub-cell on the substrate surface overlap, so that the second lower electrode 112 of the ith sub-cell and the second upper electrode 132 of the ith-1 sub-cell are at least partially in contact; the projection of the second upper electrode 132 of the ith sub-cell and the second lower electrode 112 of the (i + 1) th sub-cell on the surface of the substrate overlap, so that the second upper electrode 132 of the ith sub-cell is at least partially in contact with the second lower electrode 112 of the (i + 1) th sub-cell.

On the basis of the above-mentioned embodiments, optionally, in an embodiment of the present application, with continued reference to fig. 2 to 5, the first end of the lower electrode 11 and the third end of the upper electrode 13 of each sub-cell are located on opposite sides of the battery assembly in the second direction, and the first end of the lower electrode 11 of the i-th sub-cell is located on the second end of the lower electrode 11 of the i-th sub-cell and the second end of the lower electrode 11 of the i + 1-th sub-cell are located on the same side of the battery assembly in the second direction, that is, in this embodiment, the first end of the lower electrode 11 of the i-th sub-cell (the second lower electrode 112) and the fourth end of the upper electrode 13 thereof, the second end of the lower electrode 11 of the i-1-th sub-cell and the third end of the upper electrode 13 thereof (the second upper electrode 132), and the second ends of the lower electrode 11 of the i + 1-th sub-cell and the third end of the upper electrode 13 thereof are located on the same side of the battery assembly in the second direction The same side, such that the second lower electrode 112 of the ith sub-cell is in contact with the second upper electrode 132 of the (i-1) th sub-cell; the second end of the lower electrode 11 and the third end of the upper electrode 13 of the ith sub-cell (the second upper electrode 132), the first end of the lower electrode 11 and the fourth end of the upper electrode 11 of the (i-1) th sub-cell, and the first end of the lower electrode 11 (the second lower electrode 112) and the fourth end of the upper electrode 13 of the (i + 1) th sub-cell are all located on the same side of the battery assembly in the second direction, so that the second upper electrode 132 of the ith sub-cell is in contact with the second lower electrode 112 of the (i + 1) th sub-cell.

In order to make the lower electrodes 11 and the upper electrodes 13 of the sub-cells in the cell assembly arranged more closely and save the occupied area, in an embodiment of the present application, as shown in fig. 2 to 5, in the second direction, the projection of the first lower electrode 111 of the ith sub-cell is at least partially located within the projection range of the second lower electrode 112 of the (i + 1) th sub-cell, and the projection of the first upper electrode 131 of the ith sub-cell is at least partially located within the projection range of the second upper electrode 132 of the (i-1) th sub-cell.

On the basis of the above embodiment, in an embodiment of the present application, as shown in fig. 4, the lower electrode 11 of the 1 st sub-cell extends along the second direction, and in the second direction, the projection of the lower electrode 11 of the 1 st sub-cell is at least partially located within the projection range of the second lower electrode 112 of the 2 nd sub-cell;

as shown in fig. 5, the upper electrode 13 of the mth sub-cell extends along the second direction, and in the second direction, the upper electrode 13 of the mth sub-cell is at least partially located within the projection range of the second upper electrode 132 of the M-1 th sub-cell.

In practical applications, there is usually more than one battery assembly on the surface of the substrate, and each battery assembly is also connected in series to increase the output power, so that, on the basis of the above embodiments, in one embodiment of the present application, the at least one battery assembly includes a plurality of battery assemblies, as shown in fig. 3 to 5, the battery assembly 100 further includes: the battery pack comprises a lower connecting electrode 14 and an upper connecting electrode 15, wherein the lower connecting electrode 14 and the upper connecting electrode 15 are used for connecting the battery pack to which the battery pack belongs in series with an adjacent battery pack or are used as output electrodes of the battery pack to which the battery pack belongs. Specifically, electrode lead wires (positive and negative electrode lead wires) are formed on the lower connection electrode 14 and the upper connection electrode 15 by means of welding or the like so as to connect the associated cell assembly in series with an adjacent cell assembly or to serve as an output electrode of the associated cell assembly.

Specifically, in one embodiment of the present application, as shown in fig. 3 and 4, the lower connection electrode 14 is located at a second end (shown as end c in fig. 3) of the lower electrode 11 of the mth sub-cell, and at least partially contacts a third end (shown as end c in fig. 3) of the upper electrode of the mth sub-cell;

as shown in fig. 3 and 5, the upper connection electrode 15 is located at the fourth end (shown as the end (r) in fig. 3) of the upper electrode 13 of the 1 st sub-cell, and at least partially contacts the first end (shown as the end (r) in fig. 3) of the lower electrode 11 of the 1 st sub-cell.

As shown in fig. 3 to 5, in the present embodiment, the upper connection electrode 15 is connected to the first end of the lower electrode 11 of the 1 st sub-cell, so as to realize the series connection of the 1 st sub-cell and the sub-cell in the adjacent cell assembly, or serve as an output electrode of the cell assembly; the 1 st sub-cell is connected with the second lower electrode 132 of the 2 nd sub-cell through the second upper electrode 112 thereof, thereby realizing the series connection of the 1 st sub-cell and the 2 nd sub-cell; the second upper electrode 132 of the 2 nd sub-cell is connected to the second lower electrode 112 of the 3 rd sub-cell, thereby implementing the series connection of the 2 nd sub-cell and the 3 rd sub-cell; by analogy, the second upper electrode 132 of the M-1 th sub-cell is connected with the second lower electrode 112 of the Mth sub-cell, so that the M-1 th sub-cell and the Mth sub-cell are connected in series; the upper electrode 13 of the mth sub-cell is connected to the lower connection electrode 14, thereby realizing the series connection of the mth sub-cell to the sub-cell in the adjacent cell assembly, or as another output electrode of the cell assembly. Therefore, in the thin-film solar cell structure provided by the embodiment of the application, the sub-cells are closely arranged, so that the maximum power output of the thin-film solar cell is realized in a limited space.

In the above embodiments, as shown in fig. 3 to fig. 5, the active layer 12 of the ith sub-cell at least covers the first lower electrode 111 and the gap between the first lower electrode 111 and the second lower electrode 112 of the (i + 1) th sub-cell, so as to prevent the second upper electrode 132 of the ith sub-cell from contacting the first lower electrode 111 of the ith sub-cell to form a short circuit when contacting the second lower electrode 112 of the (i + 1) th sub-cell;

the active layer 12 of the 1 st sub-cell covers at least the lower electrode 11 thereof and the gap between the lower electrode 11 thereof and the second lower electrode 112 of the 2 nd sub-cell to prevent the second upper electrode 132 of the 1 st sub-cell from contacting the lower electrode 11 of the 1 st sub-cell to form a short circuit when contacting the second lower electrode 112 of the 2 nd sub-cell;

the active layer 12 of the mth sub-cell covers at least the first lower electrode 111 thereof and the gap between the first lower electrode 112 thereof and the lower connection electrode 14 to prevent the upper electrode 13 of the mth sub-cell from contacting the first lower electrode 111 of the mth sub-cell to form a short circuit when contacting the lower connection electrode 14.

Alternatively, fig. 6 shows a schematic layout of the lower electrode 11 and the active layer 12 of each sub-cell 10 in the cell assembly shown in fig. 2, and it can be seen from the figure that the active layer 12 of each sub-cell 10 extends along the second direction, and the length of the active layer 12 along the second direction is not less than the sum of the length of the first lower electrode 111 of the ith sub-cell along the second direction and the gap between the first lower electrode 111 of the ith sub-cell and the second lower electrode 112 of the (i + 1) th sub-cell, and the length of the active layer 12 along the second direction of each sub-cell in fig. 6 is exactly equal to the sum of the length of the first lower electrode 111 of the ith sub-cell along the second direction and the gap between the first lower electrode 111 of the ith sub-cell and the second lower electrode 112 of the (i + 1) th sub-cell.

On the basis of any of the above embodiments, as shown in fig. 7, in an embodiment of the present application, fig. 7 is a schematic longitudinal cross-sectional view of the sub-cells along the AA' direction in the cell module shown in fig. 2, and it can be seen that the active layer 12 of each sub-cell comprises a first charge transport layer 121, a perovskite light absorbing layer 122 and a second charge transport layer 123 arranged in sequence along a direction away from the substrate, i.e. the thin-film solar cell is a perovskite solar cell; at this time, when the second lower electrode 112 of the ith sub-cell is at least partially in contact with the second upper electrode 132 of the (i-1) th sub-cell, and the second upper electrode 132 of the ith sub-cell is at least partially in contact with the second lower electrode 112 of the (i + 1) th sub-cell, the upper electrodes 13 of the ith sub-cell and the (i-1) th sub-cell are directly contacted with the perovskite light-absorbing layer 122 in the active layer 12 thereof from the side, so that the corrosion of the upper electrodes 13 of the ith sub-cell and the (i-1) th sub-cell, and the degradation of the performance of the battery assembly, seriously affect the stability of the perovskite solar cell.

In view of the above, on the basis of the above embodiments, in an embodiment of the present application, as shown in fig. 7, each sub-battery further includes: and the isolation layers 16 are positioned at two opposite ends of the active layer 12 along the second direction and used for isolating the active layer 12 from being in contact with the upper electrode 13 at two opposite ends of the active layer 12 along the second direction. As can be seen from fig. 7, since the two opposite ends of the active layer 12 of the sub-cell along the second direction are provided with the isolation layers 16, when the second upper electrode 132 of the sub-cell is deposited on the second lower electrode 112 of the adjacent sub-cell, the second upper electrode 132 of the sub-cell is not in direct contact with the side surface of the active layer 12, that is, the upper electrode 13 of the sub-cell is not in direct contact with the perovskite light-absorbing layer 122, so that the perovskite light-absorbing layer of the sub-cell is prevented from corroding the upper electrode thereof, and the stability of the perovskite solar cell is improved.

Fig. 8 further shows a schematic layout of the isolating layers 16 of the sub-cells in the cell module shown in fig. 2, and it can be seen from the figure that the isolating layers 16 are located at two opposite ends of the active layer 12 of each sub-cell along the second direction, and the isolating layers 16 are located on the second lower electrodes 112 of the ith and mth sub-cells, the first ends of the lower electrodes 11 of the 1 st sub-cell, and the lower connecting electrode 14.

Fig. 8 is a schematic plan view of the active layer 12 and the separators 16 located at the two ends of the active layer 12 opposite to each other in the second direction on the lower electrode 11 of the 3 rd sub-cell, and so on, and a schematic plan view of the active layer 12 and the separators 16 located at the two ends of the active layer 12 opposite to each other in the second direction on the lower electrode 11 of each sub-cell can be obtained. Also, as can be seen from fig. 8, a projection of the isolation layer 12 in the second direction may be equal to a projection of the lower electrode 11 of each sub-cell in the second direction, which is not limited in this application, as the case may be.

Optionally, the first charge transport layer is a hole transport layer, and the second charge transport layer is an electron transport layer, but this is not limited in this application, and is specifically determined as the case may be.

Alternatively, the isolation layer 16 may be a metal bismuth layer or a silicon nitride layer, which is not limited in this application, as long as the isolation layer 16 can perform an isolation function between the active layer 12 and the upper electrode 13.

Therefore, the perovskite solar cell structure provided by the embodiment of the application further avoids direct contact between the perovskite light absorption layer of each sub-cell and the upper electrode of each sub-cell on the basis of reducing the dead zone area between adjacent sub-cells, and achieves the purposes of further avoiding corrosion of metal electrodes and improving the stability of the cell on the premise of improving the conversion efficiency of the cell.

In addition, the embodiment of the application also provides a preparation method of the thin-film solar cell structure, which comprises the following steps:

s1: providing a substrate; optionally, the substrate is a glass substrate;

s2: forming at least one battery assembly 100 on the surface of the substrate, and as shown in fig. 2, providing a schematic structural diagram of the battery assembly 100, as shown in fig. 2, the battery assembly 100 includes M sub-batteries 10 sequentially arranged at intervals along a first direction, each sub-battery 10 includes a lower electrode 11, an active layer 12 and an upper electrode 13 sequentially arranged along a direction (shown as a Z direction in fig. 2) away from the substrate, where the first direction is parallel to the surface of the substrate; reference numerals 1, 2, 3, 4, 5 … i-1, i +1 … M-1, M in fig. 2 denote the sequence of the sub-batteries 10 in the battery assembly 100 along the first direction, it should be noted that the present application does not limit the number of the sub-batteries 10 included in the battery assembly 100, and fig. 2 only illustrates a case where the battery assembly 100 includes more than 5 sub-batteries 10;

specifically, the forming process of the battery assembly 100 includes:

s21: forming a lower electrode layer on the surface of the substrate; optionally, the lower electrode layer is a transparent electrode layer;

s22: and carrying out first laser scribing on the lower electrode layer, wherein the first laser scribing at least comprises a laser scribing along a second direction, so that the lower electrode layer is divided into the lower electrodes 11 of the sub-cells, the lower electrode 11 of each sub-cell is provided with a first end and a second end which are opposite along the second direction, and the second direction is parallel to the surface of the substrate and is perpendicular to the first direction.

Specifically, the first laser scribing may be a P1 laser scribing, as shown in fig. 3 and 4, the P1 laser scribing 101 is performed on the lower electrode layer, and the P1 laser scribing 101 at least includes laser scribing along the second direction, and the etching depth reaches the substrate surface, so as to divide the lower electrode layer into the lower electrodes 11 of the sub-cells, so that the lower electrode 11 of each sub-cell has a first end and a second end opposite to each other along the second direction, as shown in fig. 4, where the first end and the second end opposite to each other along the second direction of the lower electrode 11 of any sub-cell are opposite. Optionally, the width of the P1 laser scribe line may be 70 μm.

On the basis of the foregoing embodiment, optionally, in an embodiment of the present application, as shown in fig. 4, the first laser scribe further includes a laser scribe along a third direction, where the third direction is parallel to the substrate surface and intersects with the second direction, so that the lower electrodes 11 of the ith sub-cell (i is greater than or equal to 2 and less than or equal to i and less than or equal to M-1) and the mth sub-cell include a first lower electrode 111 extending along the second direction and a second lower electrode 112 extending from one end of the first lower electrode 111 to the third direction, the second lower electrode 112 is a first end of the lower electrode 11, and one end of the first lower electrode 111 facing away from the second lower electrode 112 is a second end of the lower electrode 11.

Specifically, as shown in fig. 4, when the P1 laser scribe line 101 is performed on the lower electrode layer, the P1 laser scribe line 101 includes not only the laser scribe line along the second direction, but also the laser scribe line along the third direction, and the etching depth reaches the substrate surface, so that the lower electrodes 11 of the ith sub-cell (i is greater than or equal to 2 and is less than or equal to M-1) and the mth sub-cell include a first lower electrode 111 extending along the second direction, and a second lower electrode 112 extending from one end of the first lower electrode 111 to the third direction, the second lower electrode 112 is a first end of the lower electrode 11, and one end of the first lower electrode 111 facing away from the second lower electrode 112 is a second end of the lower electrode 11.

On the basis of the above embodiment, optionally, in an embodiment of the present application, as shown in fig. 4, the third direction is perpendicular to the second direction.

S23: an active layer 12 is formed on the lower electrode 11 of each sub-cell.

Alternatively, on the lower electrode 11 of each cell shown in fig. 4, an active layer 12 is formed.

On the basis of the above embodiment, in an embodiment of the present application, as shown in fig. 7, the active layer 12 includes a first charge transport layer 121, a perovskite light absorption layer 122 and a second charge transport layer 123 sequentially arranged in a direction away from the substrate, that is, the thin film solar cell is a perovskite solar cell, and in this case, the process of forming the active layer 12 on the lower electrode 11 of each sub-cell includes:

s231: shielding the first end and the second end of the lower electrode 11 of each sub-battery;

specifically, the first end and the second end of the lower electrode 11 of each sub-battery may be shielded by adhering a high temperature resistant adhesive tape (such as a polyimide high temperature resistant adhesive tape) or by preparing a metal mask, wherein the portions shielding the first end and the second end of the lower electrode 11 of each sub-battery are shown as the portions circled by the dashed line in fig. 4.

S232: forming the first charge transport layer 121 on the other part of the lower electrode 11 of each sub-cell except the shielded part thereof, and removing the shielding of the first end and the second end of the lower electrode 11 of each sub-cell;

s233: forming the perovskite light absorbing layer 122 on the first charge transport layer 121;

s234: laser trimming is carried out on the perovskite light absorption layer 122 corresponding to the first end and the second end of the lower electrode 11 of each sub-cell;

it should be noted that, since the perovskite light-absorbing layer 122 is usually prepared by coating, if the first end and the second end of the lower electrode 11 of each sub-cell are still shielded, the coating process of the perovskite light-absorbing layer 122 is affected, in this embodiment, after the perovskite light-absorbing layer 122 is formed on the first charge transport layer 121, laser trimming is performed on the portions of the perovskite light-absorbing layer 122 corresponding to the first end and the second end of the lower electrode 11 of each sub-cell.

S235: shielding the first end and the second end of the lower electrode 11 of each sub-cell again;

s236: the second charge transport layer 123 is formed on the perovskite light absorption layer 122, and the shielding of the first and second ends of the lower electrode 11 of each sub-cell is removed.

It should be noted that, in the above embodiment, the first charge transport layer 121 and the second charge transport layer 123 are generally prepared by thermal evaporation or magnetron sputtering, so that the first end and the second end of the lower electrode 11 of each sub-battery are shielded without affecting the preparation of the first charge transport layer 121 and the second charge transport layer 123.

S24: and carrying out secondary laser scribing on the active layer, wherein the secondary laser scribing is overlapped with the laser scribing along the second direction in the first laser scribing, so that the active layer is divided into the active layers 12 of the sub-batteries.

Specifically, the second laser scribing may be P2 laser scribing, and as shown in fig. 6, the active layer is subjected to P2 laser scribing 102, and the P2 laser scribing 102 is overlapped with the laser scribing in the second direction in the P1 laser scribing 101, so as to divide the active layer into the active layers 12 of the sub-cells.

S25: forming an upper electrode layer on the active layer 12 of each sub-cell; optionally, the upper electrode layer is a metal electrode layer.

S26: and performing third laser scribing on the upper electrode layer, so as to divide the upper electrode layer into the upper electrodes 13 of the sub-cells, so that the upper electrode 13 of each sub-cell has a third end and a fourth end opposite to each other along the second direction, as shown by a third end and a fourth end opposite to each other along the second direction of the upper electrode 13 of any sub-cell in fig. 5.

Optionally, in an embodiment of the present application, the process of forming the upper electrode layer on the active layer of each sub-cell includes:

and forming the upper electrode layer on the active layer of each sub-cell by using a mask mode, wherein the mask of the upper electrode layer is provided with a shielding part corresponding to the position of the laser scribing line along the second direction in the first laser scribing line. Specifically, as shown in fig. 9, fig. 9 shows a schematic diagram of a mask of the upper electrode layer, and a schematic diagram of an arrangement of the upper electrode of each sub-cell formed after performing a third laser scribing on the upper electrode layer formed by using the mask, as can be seen from the diagram, since the mask of the upper electrode layer has a shielding toothed portion corresponding to the laser scribing position along the second direction in the first laser scribing, optionally, the width of the shielding toothed portion may be 70 μm, the upper electrode layer is not present at the laser scribing position along the second direction in the first laser scribing, and the upper electrode layer is formed at other positions (i.e., a white area of the mask of the upper electrode layer in fig. 9).

On this basis, the upper electrode layer is subjected to a third laser scribing 103, specifically, the third laser scribing may be a P3 laser scribing, in this case, as shown in fig. 5, the third laser scribing includes a laser scribing along a fourth direction, the fourth direction is parallel to the substrate surface and intersects with the second direction, so that the upper electrodes 13 of the ith sub-cell and the 1 st sub-cell include a first upper electrode 131 extending along the second direction and a second upper electrode 132 extending from one end of the first upper electrode 131 to the fourth direction, the second upper electrode 132 is a third end of the upper electrode, and one end of the first upper electrode 131 facing away from the second upper electrode 132 is a fourth end of the upper electrode.

On the basis of the above embodiment, optionally, in an embodiment of the present application, as shown in fig. 5, the fourth direction is perpendicular to the second direction.

Of course, in other embodiments of the present application, like the first laser scribing, the upper electrode layer may be formed on the entire surface of the active layer 12 of each sub-cell, and then the upper electrode layer may be subjected to a third laser scribing, where the third laser scribing includes not only the laser scribing along the second direction, but also the laser scribing along the fourth direction, which is overlapped with the laser scribing along the second direction in the first laser scribing. The present application is not limited thereto, as the case may be.

In the thin-film solar cell structure prepared and formed by the method provided by the embodiment of the application, the first end of the lower electrode 11 of the ith sub-cell (shown as the phi end of the lower electrode 11 of the ith sub-cell in fig. 3) is connected with the third end of the upper electrode 13 of the (i-1) th sub-cell (shown as the phi end of the upper electrode 13 of the (i-1) th sub-cell in fig. 3), the third end of the upper electrode 13 of the ith sub-cell (shown as the phi end of the upper electrode 13 of the ith sub-cell in fig. 3) is connected with the first end of the lower electrode 11 of the (i + 1) th sub-cell in fig. 3), and i is more than or equal to 2 and less than or equal to M-1. It should be noted that i can be any integer between 2 and M-1.

With reference to fig. 2-5, in comparison with the conventional thin film solar cell structure, the series connection of the adjacent sub-cells is realized through three scribe grooves P1, P2 and P3, which are sequentially arranged along the first direction at two sides of the sub-cells, and the thin film solar cell structure transfers the series connection part of the adjacent sub-cells, i.e. the upper electrode and the lower electrode connection part of the adjacent sub-cells, to one end or two ends of the sub-cells along the second direction, so that the dead zone part between the adjacent sub-cells only has one scribe groove, which is equivalent to the superposition of the three scribe grooves P1, P2 and P3 extending along the second direction between the adjacent sub-cells in the prior art, i.e. two scribe grooves between the adjacent sub-cells and the distance between the adjacent scribe grooves in the prior art are removed, thereby greatly reducing the dead zone area of the thin film solar cell and increasing the light receiving area of the thin film solar cell, the conversion efficiency of the thin film solar cell is improved.

It should be noted that, in the present application, the manner of connecting the first end of the lower electrode of the ith sub-battery to the third end of the upper electrode of the (i-1) th sub-battery and connecting the third end of the upper electrode of the ith sub-battery to the first end of the lower electrode of the (i + 1) th sub-battery is not limited, and the connection may be direct contact as shown in fig. 2-5, that is, the lower electrode of the ith sub-battery is connected to the portion of the upper electrode of the (i-1) th sub-battery extending toward the ith sub-battery through the portion thereof extending toward the (i + 1) th sub-battery, and the connection may be direct contact or indirect contact through another conductor, as long as the upper and lower electrodes of adjacent sub-cells are connected by one or both ends thereof in the second direction.

As can be seen from the above description, fig. 2 only illustrates a schematic structural diagram of the cell module 100, and in the thin film solar cell structure manufactured by the method provided in the embodiments of the present application, the structure of the cell module 100 is not limited thereto, as long as in the cell module, the sub-cells are sequentially arranged at intervals along the first direction, and each sub-cell is connected in series with the adjacent sub-cell through one or both ends of the upper electrode and the lower electrode thereof along the second direction.

On the basis of the above embodiments, in one embodiment of the present application, as shown in fig. 2 to 5, for the ith sub-cell, the first lower electrode 111, the active layer 12 and the first upper electrode 131 are sequentially arranged in a direction away from the substrate surface, and are used as a main part of power generation of the sub-cell; the second lower electrode 112 of the sub-cell is at least partially contacted with the second upper electrode 132 of the (i-1) th sub-cell, so that the (i) th sub-cell is connected with the (i-1) th sub-cell in series, and the second upper electrode 132 of the sub-cell is at least partially contacted with the second lower electrode 112 of the (i + 1) th sub-cell, so that the (i) th sub-cell is connected with the (i + 1) th sub-cell in series, namely, the second lower electrode 112 and the second upper electrode 132 of the sub-cell are used as the series part of the sub-cell and the adjacent sub-cell.

When both the third direction and the fourth direction are perpendicular to the second direction, since the second lower electrode 112 of the ith sub-cell is at least partially in contact with the second upper electrode 132 of the (i-1) th sub-cell, the second upper electrode 132 of the ith sub-cell is at least partially in contact with the second lower electrode 112 of the (i + 1) th sub-cell, and the sub-cells are arranged along the first direction, the third direction is anti-parallel to the first direction, and the fourth direction is parallel to the first direction, that is, for the ith sub-cell, the second lower electrode 112 extends from one end of the first lower electrode 111 to the position close to the (i-1) th sub-cell, and the second upper electrode 132 extends from one end of the first upper electrode 131 to the position close to the (i + 1) th sub-cell.

In practical applications, there is usually more than one cell assembly on the surface of the substrate, and each cell assembly is also connected in series to increase the output power, so on the basis of any of the above embodiments, in an embodiment of the present application, the at least one cell assembly includes a plurality of cell assemblies, and when the lower electrode layer is subjected to the first laser scribing process to divide the lower electrode layer into the lower electrodes of the sub-cells, the method further includes:

s3: dividing a lower connecting electrode 14 in the lower electrode layer by using the first laser scribing line;

when the upper electrode layer is subjected to third laser scribing, so that the upper electrode layer is divided into the upper electrodes of the sub-cells, the method comprises the following steps:

s4: dividing an upper connecting electrode 15 in the upper electrode layer by the third laser scribing;

the lower connecting electrode 14 and the upper connecting electrode 15 are used for connecting the battery module to which the lower connecting electrode belongs in series with an adjacent battery module, or are used as output electrodes of the battery module to which the lower connecting electrode belongs. Specifically, electrode lead wires (positive and negative electrode lead wires) are formed on the lower connection electrode 14 and the upper connection electrode 15 by means of welding or the like so as to connect the associated cell assembly in series with an adjacent cell assembly or to serve as an output electrode of the associated cell assembly.

As is known from the foregoing, when the active layer 12 of each sub-cell includes the first charge transport layer 121, the perovskite light absorption layer 122 and the second charge transport layer 123 arranged in sequence in the direction away from the substrate, that is, when the thin-film solar cell is a perovskite solar cell, if the upper electrode 13 of each sub-cell is in direct contact with the perovskite light absorption layer 122, corrosion of the upper electrode 13 of each sub-cell and degradation of the performance of the cell assembly may be caused, which seriously affect the stability of the perovskite solar cell, and therefore, on the basis of the above-mentioned embodiments, in one embodiment of the present application, the method further includes, before forming the upper electrode layer on the active layer of each sub-cell:

s5: forming a separator 16 at both ends of the active layer 12 of each sub-cell opposite in the second direction; for any sub-cell, the separator 16 serves to separate the active layer 12 from the upper electrode 13 at its opposite ends in the second direction.

Specifically, the isolation layer 16 may be vacuum-deposited on two opposite ends of the active layer 12 of each sub-cell along the second direction by using a mask, fig. 10 shows a schematic diagram of the mask of the isolation layer 16 and a schematic diagram of the arrangement of the isolation layer formed by using the mask, and it can be seen from the diagram that the isolation layer 16 is deposited on two opposite ends of the active layer 12 of each sub-cell along the second direction.

As can be seen from fig. 7, since the two opposite ends of the active layer 12 of the sub-cell along the second direction are provided with the isolation layers 16, when the second upper electrode 132 of the sub-cell is deposited on the second lower electrode 112 of the adjacent sub-cell, the second upper electrode 132 of the sub-cell is not in direct contact with the side surface of the active layer 12, that is, the upper electrode 13 of the sub-cell is not in direct contact with the perovskite light-absorbing layer 122, so that the perovskite light-absorbing layer of the sub-cell is prevented from corroding the upper electrode thereof, and the stability of the perovskite solar cell is improved.

Therefore, the perovskite solar cell structure prepared by the method provided by the embodiment of the application further avoids the direct contact between the perovskite light absorption layer of each sub-cell and the upper electrode thereof on the basis of reducing the dead zone area between the adjacent sub-cells, and achieves the purposes of further avoiding the corrosion of the metal electrode and improving the stability of the cell on the premise of improving the conversion efficiency of the cell.

In summary, the embodiment of the present application discloses a thin film solar cell structure and a method for manufacturing the same, wherein, compared with the existing thin film solar cell structure, the series connection of adjacent sub-cells is realized through three scribe lines P1, P2, and P3 sequentially arranged along a first direction at two sides of the sub-cells, the thin film solar cell structure transfers the series connection part of the adjacent sub-cells, i.e. the upper electrode and the lower electrode connection part of the adjacent sub-cells, to one end or two ends of the adjacent sub-cells along a second direction, the second direction is perpendicular to the first direction, so that the dead zone part between the adjacent sub-cells is only provided with one scribe line, which is equivalent to the superposition of three scribe lines P1, P2, and P3 extending along the second direction between the adjacent sub-cells in the prior art, i.e. two scribe lines between the adjacent sub-cells and the distance between the adjacent scribe lines in the prior art are removed, thereby greatly reducing the dead zone area of the thin film solar cell, the light receiving area of the thin film solar cell is increased, and the conversion efficiency of the thin film solar cell is improved.

All parts in the specification are described in a mode of combining parallel and progressive, each part is mainly described to be different from other parts, and the same and similar parts among all parts can be referred to each other.

In the above description of the disclosed embodiments, features described in various embodiments in this specification can be substituted for or combined with each other to enable those skilled in the art to make or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

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Thin-film solar cell structure and preparation method thereof

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