CN118139489A - Perovskite heterojunction solar cell and preparation method thereof - Google Patents

Abstract

In the embodiment of the present disclosure, a perovskite heterojunction solar cell and a preparation method thereof are provided, the preparation method comprising providing a substrate; forming an electron collection region and a hole collection region on the back of the substrate respectively; forming a back conductive layer on the back of the electron collection region and the back of the hole collection region; forming an electrode layer on the back of the back conductive layer; and forming a perovskite half-cell structure on the upper surface of the substrate. Through the scheme of the present disclosure, a new type of solar cell structure is formed by combining a back contact heterojunction half-cell and a perovskite half-cell. Since there is no metal electrode and PN junction region on the front side, the shading loss is effectively reduced, and the sunlight is fully utilized. It has both the performance advantages of the perovskite cell structure and the performance advantages of the back contact heterojunction cell.

Description

Perovskite heterojunction solar cell and preparation method thereof

Technical Field

The present invention relates to the technical field of solar photovoltaic industry battery manufacturing, and in particular to a perovskite heterojunction solar cell and a preparation method thereof.

Background technique

Perovskite cells are new compound thin-film solar cells that use perovskite materials as light-absorbing layers and belong to the third generation of solar cells. Perovskite solar cells can be stacked with crystalline silicon solar cells, and the theoretical maximum number of stacking layers is 4. The main advantage of perovskite stacked cells is the full utilization of the solar spectrum. However, the front of traditional stacked cells is blocked by grid lines, and the shading loss causes the cell efficiency to be reduced. The optimization of grid line width has always been an important direction to improve the light utilization rate of solar cells and the overall efficiency of the cells. The back contact technology can completely avoid the cell efficiency loss caused by grid line blocking.

Heterojunction solar cells have the characteristics of simple process and high theoretical efficiency. Compared with existing PERC, TOPcon and other cell structures, the obvious feature of heterojunction cell structure is that it has an intrinsic amorphous silicon passivation layer. In addition, the process route of heterojunction solar cells is relatively simple and has good compatibility with the back contact cell technology route. However, the back contact silicon-based cell technology route does not involve heterojunction solar cell technology.

Summary of the invention

In view of this, the embodiments of the present disclosure provide a perovskite heterojunction solar cell and a method for preparing the same, which at least partially solve the problems existing in the prior art, combine the perovskite cell and the back-contact heterojunction cell to form a new solar cell structure, and obtain optimized cell performance while effectively obtaining solar energy.

In a first aspect, an embodiment of the present disclosure provides a method for preparing a perovskite heterojunction solar cell, comprising:

providing a substrate;

forming an electron collection region and a hole collection region on the back side of the substrate;

forming a back conductive layer on the back of the electron collection region and the back of the hole collection region;

forming an electrode layer on the back side of the back conductive layer;

A perovskite half-cell structure is formed on the upper surface of the substrate.

According to a specific implementation of the embodiment of the present disclosure, providing a substrate includes:

providing a substrate;

A front passivation layer and a back passivation layer are formed on the front side of the substrate and the back side of the substrate respectively.

According to a specific implementation of the embodiment of the present disclosure, the forming of a perovskite half-cell structure on the upper surface of the substrate includes:

forming a front conductive layer on the upper surface of the front passivation layer;

A perovskite absorption layer is formed on the upper surface of the front conductive layer.

According to a specific implementation of the embodiment of the present disclosure, the forming of a perovskite half-cell structure on the upper surface of the substrate further includes:

forming an anti-reflection layer on the upper surface of the perovskite absorption layer;

The front conductive layer, the perovskite absorption layer and the anti-reflection layer together constitute the perovskite half-cell structure.

According to a specific implementation of the embodiment of the present disclosure, the electron collection regions and the hole collection regions are arranged alternately and spaced apart, and the width of the electrode layer is smaller than the width of the back conductive layer.

According to a specific implementation of the embodiment of the present disclosure, the front passivation layer, the substrate, the back passivation layer, the electron collection region, the hole collection region, the back conductive layer and the electrode layer together constitute a back contact heterojunction half-cell structure.

In a second aspect, the embodiments of the present disclosure provide a perovskite heterojunction solar cell, comprising:

substrate;

a perovskite half-cell structure covering the upper surface of the substrate;

The electron collection region and the hole collection region are both located on the back side of the substrate;

A back conductive layer, located on the back of the electron collection area and the back of the hole collection area;

The electrode layer is located on the back side of the back conductive layer.

According to a specific implementation of the embodiment of the present disclosure, the substrate includes:

substrate;

A front passivation layer covering the front side of the substrate;

A back passivation layer covers the back side of the substrate.

According to a specific implementation of the embodiment of the present disclosure, the perovskite half-cell structure includes a front conductive layer, a perovskite absorption layer, and an anti-reflection layer stacked in sequence from bottom to top;

The front passivation layer, the substrate, the back passivation layer, the electron collection region, the hole collection region, the back conductive layer and the electrode layer together constitute a back contact heterojunction half-cell structure.

According to a specific implementation of the embodiment of the present disclosure, the electron collection regions and the hole collection regions are arranged alternately and spaced apart, and the width of the electrode layer is smaller than the width of the back conductive layer.

The perovskite heterojunction solar cell and its preparation method in the embodiment of the present disclosure, the preparation method comprises providing a substrate; forming an electron collection area and a hole collection area on the back of the substrate respectively; forming a back conductive layer on the back of the electron collection area and the back of the hole collection area; forming an electrode layer on the back of the back conductive layer; forming a perovskite half-cell structure on the upper surface of the substrate. Through the scheme of the present disclosure, a new type of solar cell structure is formed by combining a back contact heterojunction half-cell and a perovskite half-cell. Since there is no metal electrode and PN junction area on the front side, the shading loss is effectively reduced, the sunlight is fully utilized, and the performance of the battery is greatly improved. It has both the performance advantages of the perovskite battery structure and the performance advantages of the back contact heterojunction battery.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

FIG1 is a flow chart of a method for preparing a perovskite heterojunction solar cell provided in an embodiment of the present disclosure;

FIG2 is a schematic diagram of the structure of a perovskite heterojunction solar cell provided in an embodiment of the present disclosure.

Description of reference numerals: 10, perovskite half-cell structure; 11, front conductive layer; 12, perovskite absorption layer; 13, anti-reflection layer;

20. Back contact heterojunction half-cell structure; 21. Base; 211. Substrate; 212. Front passivation layer; 213. Back passivation layer; 22. Electron collection region; 23. Hole collection region; 24. Back conductive layer; 25. Electrode layer.

Detailed ways

In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present application are given in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and/or" used herein includes any and all combinations of one or more of the related listed items.

It should be understood that when an element or layer is referred to as "on ...", "adjacent to ...", "connected to" or "coupled to" other elements or layers, it can be directly on, adjacent to, connected to or coupled to other elements or layers, or there can be intervening elements or layers. On the contrary, when an element is referred to as "directly on ...", "directly adjacent to ...", "directly connected to" or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc. can be used to describe various elements, components, regions, layers and/or parts, these elements, components, regions, layers and/or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present application, the first element, component, region, layer or part discussed below can be represented as the second element, component, region, layer or part.

Spatially relative terms such as "under," "beneath," "below," "under," "above," "above," and the like may be used herein for ease of description to describe the relationship of an element or feature shown in the figures to other elements or features. It should be understood that the spatially relative terms are intended to include different orientations of the device in use and operation in addition to the orientations shown in the figures. For example, if the device in the accompanying drawings is flipped, then the elements or features described as "under other elements" or "under" or "under" will be oriented as "on" the other elements or features. Thus, the exemplary terms "under" and "under" may include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or other orientations) and the spatial descriptors used herein are interpreted accordingly.

The purpose of the terms used herein is only to describe specific embodiments and is not intended to be limiting of the present application. When used herein, the singular forms "one", "an" and "said/the" are also intended to include plural forms, unless the context clearly indicates another way. It should also be understood that the terms "consisting of" and/or "comprising", when used in this specification, determine the presence of the features, integers, steps, operations, elements and/or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and/or groups. When used herein, the term "and/or" includes any and all combinations of the relevant listed items.

Embodiments of the application are described herein with reference to cross-sectional views that are schematic diagrams of ideal embodiments (and intermediate structures) of the application. Thus, variations from the shapes shown due to, for example, manufacturing techniques and/or tolerances can be expected. Therefore, embodiments of the application should not be limited to the specific shapes of the zones shown herein, but include shape deviations due to, for example, manufacturing, and the zones shown in the figures are schematic in nature, and their shapes are not intended to display the actual shapes of the zones of the device and are not intended to limit the scope of the application.

In one embodiment of the present application, as shown in FIG1 , a novel heterojunction battery preparation method is provided, comprising the following steps:

Step S10: providing a substrate 21;

Step S20: forming an electron collection region 22 and a hole collection region 23 on the back side of the substrate 21;

Step S30: forming a back conductive layer 24 on the back side of the electron collection region 22 and the back side of the hole collection region 23;

Step S40: forming an electrode layer 25 on the back side of the back conductive layer 24;

Step S50 : forming a perovskite half-cell structure 10 on the upper surface of the substrate 21 .

The back-contact heterojunction solar cell structure is a new type of cell structure developed on the basis of heterojunction solar cells. The main feature of the back-contact heterojunction solar cell structure is that there is no grid line and pn junction area on the front side, thereby reducing shading loss and making full use of solar energy.

The perovskite heterojunction solar cell and its preparation method in the embodiment of the present disclosure, the preparation method includes providing a substrate; forming an electron collection area and a hole collection area on the back of the substrate respectively; forming a back conductive layer on the back of the electron collection area and the back of the hole collection area; forming an electrode layer on the back of the back conductive layer; forming a perovskite half-cell structure on the upper surface of the substrate. Through the scheme of the present disclosure, the back contact heterojunction half-cell and the perovskite half-cell are combined to form a new solar cell structure. The perovskite half-cell converts the absorbed sunlight into electrons and holes, and the electrons and holes are transported to the electron collection area and the hole collection area respectively by the lower substrate, and finally the electrons and holes are transferred to the electrode layer by the back conductive layer. Since there is no metal electrode and PN junction area on the front side, the shading loss is effectively reduced, the sunlight is fully utilized, and the performance of the battery is greatly improved. It has both the performance advantages of the perovskite battery structure and the performance advantages of the back contact heterojunction battery.

In one embodiment, as shown in FIG. 2 , the substrate 21 provided in step S10 includes the following steps:

Step S11: providing a substrate 211;

Step S12: forming a front passivation layer 212 and a back passivation layer 213 on the front surface of the substrate 211 and the back surface of the substrate 211 respectively.

Specifically, the substrate 211 includes but is not limited to N-type silicon wafer n-c-Si, etc. If an N-type silicon wafer is used as the substrate 211, a texturing and cleaning process is required to improve the cleanliness of the silicon wafer surface and reduce the appearance of impurities. Here, the entire texturing and cleaning process is well known to those skilled in the art and will not be described in detail here.

Specifically, both the front passivation layer 212 and the back passivation layer 213 can be prepared by PECVD, and the thickness of the front passivation layer 212 and the back passivation layer 213 are both 5nm-10nm. For example, the thickness of the front passivation layer 212 is 5nm, 6nm, 7nm, 8nm, 9nm or 10nm; the thickness of the back passivation layer 213 is 5nm, 6nm, 7nm, 8nm, 9nm or 10nm; the front passivation layer 212 and the back passivation layer 213 include but are not limited to i-Si:H layer; the front passivation layer 212 and the back passivation layer 213 are used to reduce the probability of carrier interface recombination, that is, to reduce the probability of electron and hole recombination.

As an example, the materials of the front passivation layer 212 and the back passivation layer 213 may be the same or different, and may be prepared at the same time to save preparation process.

In one embodiment, please continue to refer to FIG. 2. The electron collection region 22 and the hole collection region 23 are formed in step S20, which can be prepared by using a graphical technology combined with a PEVCD method. The electron collection region 22 and the hole collection region 23 are arranged alternately and spaced apart, with a gap between them. Electrons have better migration ability than holes, and the width of the electron collection region 22 is greater than the width of the hole collection region 23. The area of the electron collection region 22 is greater than the area of the hole collection region 23, that is, the area of the positive projection of the electron collection region 22 on the substrate 21 is greater than the area of the positive projection of the hole collection region 23 on the substrate, so as to make up for the defect of performance degradation caused by low hole migration ability.

Specifically, the electron collection region 22 includes but is not limited to an N-type hydrogenated amorphous silicon layer (n-Si:H) and the like, and the hole collection region 23 includes but is not limited to a P-type hydrogenated amorphous silicon layer (p-Si:H) and the like.

The width of the electrode layer 25 is smaller than the width of the back conductive layer 24. The back conductive layer 24 completely covers the back side of the electron collection area 22 and the back side of the hole collection area 23 to transfer all generated electrons and holes into the electrode layer 25, thereby reducing the transmission loss of electrons and holes.

In one embodiment, the back conductive layer prepared in step S30 includes but is not limited to a TCO layer, which can be aligned using a patterning technique and prepared by evaporation using a PVD technique.

In one embodiment, please continue to refer to Figure 2, the front passivation layer 212, the substrate 211, the back passivation layer 213, the electron collection region 22, the hole collection region 23, the back conductive layer 24 and the electrode layer 25 together constitute a back contact heterojunction half-cell structure 20.

In one embodiment, please continue to refer to FIG. 2 , in step S50: forming a perovskite half-cell structure 10 on the upper surface of the substrate 21 specifically includes the following steps:

Step S51: forming a front conductive layer 11 on the upper surface of the front passivation layer 212;

Step S52 : forming a perovskite absorption layer 12 on the upper surface of the front conductive layer 11 .

Specifically, the front conductive layer 11 includes but is not limited to a TCO transparent conductive layer; the transparent conductive layer TCO may be evaporated using PVD technology.

The front conductive layer 11 and the back conductive layer 24 may be prepared simultaneously, or, if necessary, may be prepared separately.

In one embodiment, the perovskite absorption layer 12 can be prepared by using a solution method, a coating method, a PVD method, or the like; the material of the perovskite absorption layer 12 includes but is not limited to an organic material, an inorganic material, or an organic-inorganic hybrid material, and the like.

In one embodiment, please continue to refer to FIG. 2 , in step S20: forming a perovskite half-cell structure 10 on the upper surface of the substrate 21 specifically includes the following steps:

Step S53: forming an anti-reflection layer 13 on the upper surface of the perovskite absorption layer 12;

Specifically, the anti-reflection layer 13 is used to reduce the reflection of sunlight, so that the perovskite absorption layer 12 absorbs as much sunlight as possible and reduces the loss of sunlight. The material of the anti-reflection layer 13 is not limited, and any material that meets the above functions can be used as the anti-reflection layer 13 of the present application.

The front conductive layer 11 , the perovskite absorption layer 12 and the anti-reflection layer 13 together constitute the perovskite half-cell structure 10 .

It should be noted that if the architecture of the perovskite half-cell structure 10 and the back contact heterojunction half-cell structure 20 used is the same as that of the present application, or is an extension of the architecture of the present application, it can fall within the scope of protection of the present application.

In another embodiment of the present application, a perovskite heterojunction solar cell is provided, characterized in that it includes: a substrate 21; a perovskite half-cell structure 10, covering the upper surface of the substrate 21; an electron collection region 22 and a hole collection region 23, both located on the back side of the substrate 21; a back conductive layer 24, located on the back side of the electron collection region 22 and the back side of the hole collection region 23; and an electrode layer 25, located on the back side of the back conductive layer 24.

In one embodiment, the base 21 includes: a substrate 211 ; a front passivation layer 212 covering the front side of the substrate 211 ; and a back passivation layer 213 covering the back side of the substrate 211 .

In one embodiment, the electron collecting regions 22 and the hole collecting regions 23 are arranged alternately and spaced apart, and the width of the electrode layer 25 is smaller than the width of the back conductive layer 24 .

In one embodiment, the perovskite half-cell structure 10 includes a front conductive layer 11, a perovskite absorption layer 12, and an anti-reflection layer 13 stacked in sequence from bottom to top; the front passivation layer 212, the substrate 211, the back passivation layer 213, the electron collection region 22, the hole collection region 23, the back conductive layer 24 and the electrode layer 25 together constitute a back contact heterojunction half-cell structure 20.

The above is only a specific implementation of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present disclosure should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims (10)

1. A method for fabricating a perovskite heterojunction solar cell, comprising:

Providing a substrate;

forming an electron collecting region and a hole collecting region on the back surface of the substrate respectively;

forming a back conductive layer on the back of the electron collecting region and the back of the hole collecting region;

forming an electrode layer on the back surface of the back surface conductive layer;

and forming a perovskite half-cell structure on the upper surface of the substrate.

2. The method of claim 1, wherein providing a substrate comprises:

Providing a substrate;

And forming a front passivation layer and a back passivation layer on the front surface of the substrate and the back surface of the substrate respectively.

3. The method of fabricating a perovskite heterojunction solar cell according to claim 2, wherein the forming a perovskite half-cell structure on the upper surface of the substrate comprises:

Forming a front conductive layer on the upper surface of the front passivation layer;

and forming a perovskite absorption layer on the upper surface of the front conductive layer.

4. A method of fabricating a perovskite heterojunction solar cell as claimed in claim 3 wherein said forming a perovskite half cell structure on an upper surface of said substrate further comprises:

forming an anti-reflection layer on the upper surface of the perovskite absorption layer;

Wherein the front side conductive layer, the perovskite absorption layer and the anti-reflection layer together form the perovskite half-cell structure.

5. The method for manufacturing a perovskite heterojunction solar cell according to claim 1, wherein the electron collecting regions and the hole collecting regions are alternately arranged at intervals, and the width of the electrode layer is smaller than the width of the back conductive layer.

6. The method of claim 2, wherein the front side passivation layer, the substrate, the back side passivation layer, the electron collection region, the hole collection region, the back side conductive layer, and the electrode layer together comprise a back contact heterojunction half-cell structure.

7. A perovskite heterojunction solar cell, comprising:

a substrate;

A perovskite half cell structure covering the upper surface of the substrate;

The electron collecting region and the hole collecting region are positioned on the back surface of the substrate;

a back conductive layer located on the back of the electron collecting region and the back of the hole collecting region;

and the electrode layer is positioned on the back surface of the back surface conductive layer.

8. The perovskite heterojunction solar cell of claim 7, wherein the substrate comprises:

A substrate;

a front passivation layer covering the front surface of the substrate;

and the back passivation layer covers the back surface of the substrate.

9. The perovskite heterojunction solar cell of claim 8, wherein the perovskite half cell structure comprises a front side conductive layer, a perovskite absorption layer, and an anti-reflection layer laminated in sequence from bottom to top;

the front passivation layer, the substrate, the back passivation layer, the electron collection region, the hole collection region, the back conductive layer, and the electrode layer together form a back contact heterojunction half-cell structure.

10. The perovskite heterojunction solar cell of claim 7, wherein the electron collection regions and the hole collection regions are alternately arranged at intervals, and the width of the electrode layer is smaller than the width of the back conductive layer.