CN220821575U - Battery structure and photovoltaic module - Google Patents

Abstract

The present invention relates to a battery structure and a photovoltaic module. The battery structure comprises: a silicon substrate, which comprises a front side and a back side; a tunneling layer, which covers the back side of the silicon substrate; a first semiconductor doping layer, which covers the bottom side of the tunneling layer; a first passivation layer, which covers the bottom side of the first semiconductor doping layer, and comprises a silicon oxide layer; a first anti-reflection layer, which covers the bottom side of the first passivation layer, and comprises at least one silicon nitride layer. In this way, the requirements of the battery structure for light transmittance can be met, and the passivation effect of the back side of the battery structure can be further improved.

Description

Battery structure and photovoltaic modules

Technical Field

The present application relates to the technical field of solar cells, and in particular to a cell structure and a photovoltaic module.

Background technique

At present, in order to improve the performance of solar cells, coatings with different structures are formed on the front and back of the solar cell. For example, a passivation layer is formed on the front and back of the cell to reduce the recombination rate and increase the carrier lifetime.

In order to ensure the photoelectric conversion efficiency of solar cells, silicon nitride is usually used as the back passivation layer of solar cells. However, the surface passivation effect, film quality and high-temperature stability of silicon nitride are relatively poor. How to improve the passivation effect of the back passivation layer of solar cells has become an urgent problem to be solved.

Summary of the invention

Based on this, it is necessary to provide a cell structure and a photovoltaic module to address the problems of relatively poor surface passivation effect, film forming quality and high temperature stability of the back passivation layer of solar cells in the prior art.

In order to achieve the above objectives, in a first aspect, the present invention provides a battery structure, comprising:

A silicon substrate, wherein the silicon substrate comprises a front side and a back side;

A tunneling layer, wherein the tunneling layer covers the back side of the silicon substrate;

A first semiconductor doping layer, wherein the first semiconductor doping layer covers a bottom surface of the tunneling layer;

a first passivation layer, the first passivation layer covering a bottom surface of the first semiconductor doping layer, the first passivation layer comprising a silicon oxide layer;

A first anti-reflection layer covers a bottom surface of the first passivation layer, and the first anti-reflection layer includes at least one silicon nitride layer.

In one embodiment, the refractive index of the first anti-reflection layer is greater than the refractive index of the first passivation layer.

In one embodiment, the refractive index of at least one silicon nitride layer gradually decreases in a direction away from the first passivation layer.

In one of the embodiments, at least one layer of the silicon nitride layer is doped with hydrogen ions, and the doping concentration of the hydrogen ions in the at least one layer of the silicon nitride layer gradually decreases in a direction away from the first passivation layer.

In one embodiment, the first anti-reflection layer includes a first silicon nitride layer, a second silicon nitride layer, and a third silicon nitride layer stacked on the bottom surface of the first passivation layer.

In one embodiment, the thickness of the first passivation layer is 3nm-4nm.

In one embodiment, the battery structure further comprises:

An emitter, the emitter being located on the front side of the silicon substrate;

A second passivation layer, wherein the second passivation layer covers a top surface of the emitter, and an ohmic contact is formed between the second passivation layer and a contact surface of the emitter.

In one of the embodiments, the second passivation layer at least includes an aluminum oxide layer disposed on and connected to the top surface of the emitter.

In one embodiment, the first semiconductor doping layer has an N-type conductivity type, and the emitter has a P-type conductivity type.

In a second aspect, the present invention provides a photovoltaic module, comprising the battery structure as described in the first aspect of the present invention.

In the novel battery structure and photovoltaic module, the first passivation layer and the first anti-reflection layer are stacked on the back of the silicon substrate. The first passivation layer has good surface passivation effect, film-forming quality and high-temperature stability. The first anti-reflection layer has good passivation effect and light transmission effect. In this way, the requirements of the battery structure for light transmission can be met, and the passivation effect on the back of the battery structure can be further improved.

BRIEF DESCRIPTION OF THE DRAWINGS

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

FIG. 1 is a schematic diagram of a battery structure provided in an embodiment.

FIG. 2 is a schematic diagram of a battery structure provided in an embodiment.

FIG. 3 is a schematic diagram of a battery structure provided in an embodiment.

Description of reference numerals:

1. Silicon substrate; 1a. Front side; 1b. Back side; 2. Tunneling layer; 3. First semiconductor doping layer; 4. First passivation layer; 5. First anti-reflection layer; 51. First silicon nitride layer; 52. Second silicon nitride layer; 53. Third silicon nitride layer; 6. Emitter; 7. Second passivation layer; 71. Aluminum oxide layer; 72. Silicon nitride passivation layer; 73. Silicon oxynitride passivation layer; 74. Silicon oxide passivation 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.

In the related art, in order to ensure the photoelectric conversion efficiency of solar cells, silicon nitride is usually selected as the back passivation layer of solar cells. However, the surface passivation effect, film quality and high-temperature stability of silicon nitride are relatively poor. How to improve the passivation effect of the back passivation layer of solar cells has become an urgent problem to be solved.

In order to solve the above technical problems, the present application provides a battery structure, which includes a silicon substrate, a tunneling layer, a first semiconductor doping layer, a first passivation layer and a first anti-reflection layer; the silicon substrate includes a front side and a back side, and the tunneling layer, the first semiconductor doping layer, the first passivation layer and the first anti-reflection layer are sequentially arranged on the back side of the silicon substrate, wherein the first passivation layer includes a silicon oxide layer, and the first anti-reflection layer includes at least one silicon nitride layer. In the battery structure of this embodiment, the first passivation layer arranged on the back side of the silicon substrate includes a silicon oxide layer, and the first anti-reflection layer arranged on the bottom surface of the first passivation layer includes at least one silicon nitride layer, and the silicon oxide has the characteristics of good surface passivation effect, film forming quality and high temperature stability, and the silicon nitride has good passivation effect and light transmission effect. In this way, the first passivation layer and the first anti-reflection layer are stacked on the back side of the silicon substrate, which can not only meet the requirements of the battery structure for light transmission, but also further improve the passivation effect of the back side of the battery structure.

According to an exemplary embodiment, this embodiment provides a battery structure, and the battery structure of this embodiment is applied to photovoltaic cells, such as PERC (Passivated Emitter Rear Cell), TOPCON (Tunnel Oxide Passivated Contact) or IBC (Interdigitated Back Contact) and other batteries. As shown in FIG1 , the battery structure of this embodiment includes a silicon substrate 1, a tunneling layer 2, a first semiconductor doping layer 3, a first passivation layer 4 and a first anti-reflection layer 5. The silicon substrate 1 can be an N-type substrate or a P-type substrate. The silicon substrate 1 includes a front side 1a and a back side 1b. The front side 1a and the back side 1b of the silicon substrate 1 are arranged opposite to each other. The tunneling layer 2 covers the back side 1b of the silicon substrate 1. The material of the tunneling layer 2 may include at least one of silicon oxide, silicon nitride, silicon oxynitride, silicon carbide or magnesium fluoride. The first semiconductor doping layer 3 covers the bottom surface of the tunneling layer 2. The first semiconductor doping layer 3 is a conductive layer. The first semiconductor doping layer 3 has an N-type conductivity type or a P-type conductivity type. The first semiconductor doping layer 3 and the silicon substrate 1 have the same conductivity type. The material of the first semiconductor doping layer 3 may include at least one of amorphous silicon, polycrystalline silicon or silicon carbide. The first passivation layer 4 covers the bottom surface of the first semiconductor doping layer 3. The first passivation layer 4 includes a silicon oxide layer. The first anti-reflection layer 5 covers the bottom surface of the first passivation layer 4. The first anti-reflection layer 5 The invention comprises at least one silicon nitride layer, the silicon oxide layer of the first passivation layer 4 has good surface passivation effect, film-forming quality and high-temperature stability, the silicon nitride layer of the first anti-reflection layer 5 has good passivation effect, the first passivation layer 4 and the first anti-reflection layer 5 are stacked on the back side 1b of the silicon substrate 1, and have good passivation effect on the back side 1b of the silicon substrate 1, reduce the defect state density of the back side 1b of the silicon substrate 1, and better inhibit the carrier recombination of the back side 1b of the silicon substrate 1, and at the same time, the silicon nitride layer of the first anti-reflection layer 5 has good light transmittance, the first anti-reflection layer 5 has good anti-reflection effect, reduces the reflection of the back side 1b of the silicon substrate 1 on the incident light, and improves the utilization rate of the battery structure on the incident light.

In some embodiments, the first anti-reflection layer 5 may be a single-layer structure, and the first anti-reflection layer 5 only includes a silicon nitride layer.

In some embodiments, the first anti-reflection layer 5 may also include a multilayer structure stacked in sequence on the bottom surface of the first passivation layer 4, at least one layer in the multilayer structure is a silicon nitride layer, and the materials of other layers in the multilayer structure may include at least one of silicon nitride, silicon oxynitride or aluminum oxide; the materials of each layer in the multilayer structure may be different from each other, or the materials of a part of the number of layers may be different from each other, and the materials of the remaining part of the number may be the same. For example, the first anti-reflection layer 5 may be a multilayer structure of a silicon nitride layer and an aluminum oxide layer.

The manufacturing process of the battery structure needs to undergo several high-temperature sinterings, or the working environment of the battery structure may also be in a high-temperature environment. The silicon oxide layer has good high-temperature stability and can improve the passivation effect on the back of the battery structure in a high-temperature environment. The silicon oxide layer and the first semiconductor doping layer 3 have good lattice matching, and the film density of the silicon oxide layer is high, and the surface passivation effect, film quality and high-temperature stability performance are good. The first passivation layer 4 is set on the back side 1b of the silicon substrate 1 to form a good protection for the back side 1b of the silicon substrate 1. The silicon nitride layer of the first anti-reflection layer 5 has good light transmittance and passivation effect.

In this embodiment, a first passivation layer 4 is arranged between the first anti-reflection layer 5 and the first semiconductor doping layer 3. The first anti-reflection layer 5 is combined with the first semiconductor doping layer 3 through the first passivation layer 4, which can improve the bonding force between the first anti-reflection layer 5 and the first semiconductor doping layer 3, so that the first anti-reflection layer 5 and the first semiconductor doping layer 3 are firmly combined together, which can prevent the film layer on the back side of the battery structure from falling off. At the same time, the first passivation layer 4 and the first anti-reflection layer 5 form protection for the back side of the battery structure, strengthen the passivation effect of the back side of the battery structure, and prevent the back side of the battery structure from being corroded and damaged.

In some embodiments, as shown in FIG. 1 , the refractive index of the first anti-reflection layer 5 is greater than the refractive index of the first passivation layer 4 , and the first anti-reflection layer 5 has good light transmittance to ensure the transmittance of light through the first anti-reflection layer 5 , so as to increase the light receiving rate of the battery structure, and the battery structure generates a voltaic effect to form an electromotive force.

This embodiment does not limit the thickness of the first passivation layer 4. Properly increasing the thickness of the first passivation layer 4 can enhance the protection effect on the back of the battery structure and further enhance the bonding force between the first anti-reflection layer 5 and the first semiconductor doping layer 3. However, the refractive index of the first passivation layer 4 is relatively small, and the light transmittance is relatively poor. Increasing the thickness of the first passivation layer 4 may affect the light receiving rate of the battery structure.

In some embodiments, as shown in FIG1 , the thickness of the first passivation layer 4 is 3 nm to 4 nm, so that the first passivation layer 4 and the first anti-reflection layer 5 can enhance the protective effect of the back of the battery structure while avoiding the first passivation layer 4 from affecting the light receiving rate of the battery structure. For example, the thickness of the first passivation layer 4 can be 3 nm, 3.1 nm, 3.2 nm, 3.3 nm, 3.4 nm, 3.5 nm, 3.6 nm, 3.7 nm, 3.8 nm, 3.9 nm or 4 nm.

The present embodiment does not limit the thickness of the first anti-reflection layer 5. Based on the stability of the film layer of the battery structure and the passivation effect of the back of the battery structure, the thickness of the first anti-reflection layer 5 can be 75nm-90nm. For example, the thickness of the first anti-reflection layer 5 can be 75nm, 77nm, 79nm, 81nm, 93nm, 85nm, 87nm, 99nm or 90nm.

The present embodiment does not limit the number of layers of the first anti-reflection layer 5, and the first anti-reflection layer 5 may be a single-layer or multi-layer structure. For example, the first anti-reflection layer 5 may include only one silicon nitride layer, or the first anti-reflection layer 5 may include two or more silicon nitride layers stacked in sequence under the bottom surface of the first passivation layer 4.

In some embodiments, as shown in FIG1 , the refractive index of at least one silicon nitride layer gradually decreases in a direction away from the first passivation layer 4. The first anti-reflection layer 5 may include only one silicon nitride layer, and the refractive index of the silicon nitride layer gradually decreases in a direction away from the first passivation layer 4, that is, the refractive index of the incident surface of the light in the first anti-reflection layer 5 is the smallest; or the first anti-reflection layer 5 may include multiple silicon nitride layers, and the refractive index of the multiple silicon nitride layers decreases in a step-like manner in a direction away from the first passivation layer 4, that is, the refractive index of the incident layer of the light in the first anti-reflection layer 5 is the smallest. In this way, the amount of reflection of the light incident to the first anti-reflection layer 5 can be reduced, and more light can be transferred to the silicon substrate 1 for photoelectric conversion.

At the same time, when the battery structure of this embodiment performs photoelectric conversion, along the incident path of the light from the first anti-reflection layer 5 to the back side 1b of the silicon substrate 1, the refractive index of the light gradually increases after passing through the first anti-reflection layer 5. In this way, after the transfer of the first anti-reflection layer 5, the direction of the light incident on the back side 1b of the silicon substrate 1 can be adjusted so that the light is vertically incident on the back side 1b of the silicon substrate 1, further increasing the photoelectric conversion efficiency of the battery structure.

It is understandable that, in the process of forming the first anti-reflection layer 5, the refractive index of the formed silicon nitride layer can be adjusted by adjusting the process parameters for forming the silicon nitride layer, so that the silicon nitride layers at different layers have different refractive indices. For example, when forming the first anti-reflection layer 5, silane (SiH ₄ ) and ammonia (NH ₃ ) are used as gas sources, and at least one silicon nitride layer is formed by a plasma enhanced chemical vapor deposition process, and the refractive index of the silicon nitride layer is increased by increasing the proportion of silane, and the refractive index of the silicon nitride layer is reduced by reducing the proportion of silane, so that the refractive index of the silicon nitride layer gradually decreases along the direction away from the first passivation layer 4.

In some embodiments, as shown in FIG1 , at least one silicon nitride layer is doped with hydrogen ions, and the doping concentration of hydrogen ions in at least one silicon nitride layer gradually decreases in a direction away from the first passivation layer 4. The doping concentration of hydrogen ions may gradually decrease in a direction away from the first passivation layer 4; or, the doping concentration of hydrogen ions in multiple silicon nitride layers may decrease in a stepwise manner in a direction away from the first passivation layer 4.

The surface of the silicon substrate 1 may have defects, such as pits or scratches, and silicon dangling bonds gather at the defects on the surface of the silicon substrate 1. In this example, the hydrogen ion concentration of the silicon nitride layer close to the first passivation layer 4 in the first anti-reflection layer 5 is the highest, and the hydrogen ions in the silicon nitride layer can neutralize the silicon dangling bonds gathered on the back side 1b of the silicon substrate 1, thereby preventing the free silicon dangling bonds from affecting the passivation effect of the back side 1b of the silicon substrate 1.

In the process of forming the first anti-reflection layer 5, the content of hydrogen ions in the formed silicon nitride layer can be adjusted by adjusting the process parameters for forming the silicon nitride layer. For example, the content of hydrogen ions in the silicon nitride layer can be increased by increasing the proportion of silane, and the content of hydrogen ions in the silicon nitride layer can be reduced by reducing the proportion of silane. This can achieve a gradual decrease in the doping concentration of hydrogen ions in at least one silicon nitride layer away from the first passivation layer 4.

According to an exemplary embodiment, as shown in FIG. 2 , this embodiment provides a battery structure, which includes a silicon substrate 1, a tunneling layer 2, a first semiconductor doping layer 3, a first passivation layer 4 and a first anti-reflection layer 5; the silicon substrate 1 includes a front side 1a and a back side 1b that are arranged opposite to each other, and the tunneling layer 2, the first semiconductor doping layer 3, the first passivation layer 4 and the first anti-reflection layer 5 are sequentially arranged on the back side 1b of the silicon substrate 1, wherein the first passivation layer 4 includes a silicon oxide layer, and the thickness of the first passivation layer 4 is 3nm-4nm, and the first anti-reflection layer 5 includes a first silicon nitride layer 51, a second silicon nitride layer 52 and a third silicon nitride layer 53 that are stacked on the bottom surface of the first passivation layer 4.

The refractive index of the first silicon nitride layer 51 is n1, the refractive index of the second silicon nitride layer 52 is n2, and the refractive index of the third silicon nitride layer 53 is n3, and n1>n2 is greater than n3.

The content of hydrogen ions in the first silicon nitride layer 51 is greater than the content of hydrogen ions in the second silicon nitride layer 52 and greater than the content of hydrogen ions in the third silicon nitride layer 53 .

In some examples, the refractive index n1 of the first silicon nitride layer 51 is 2.2-2.3, the refractive index n2 of the second silicon nitride layer 52 is 2.1-2.2, and the refractive index n3 of the third silicon nitride layer 53 is 2.0-2.1. It is understandable that although the numerical ranges of the first silicon nitride layer 51, the second silicon nitride layer 52, and the third silicon nitride layer 53 have overlapping areas, it is sufficient to ensure that n1>n2 is greater than n3 in the selection of the implementation method.

In some embodiments, the thicknesses of the first silicon nitride layer 51 , the second silicon nitride layer 52 , and the third silicon nitride layer 53 may be the same.

In some embodiments, the thickness of the first silicon nitride layer 51 is less than the thickness of the second silicon nitride layer 52, and the thickness of the second silicon nitride layer 52 is less than the thickness of the third silicon nitride layer 53. For example, the thickness of the first silicon nitride layer 51 ranges from 15nm to 20nm, the thickness of the second silicon nitride layer 52 ranges from 25nm to 30nm, and the thickness of the third silicon nitride layer 53 ranges from 30nm to 40nm.

In the process of photoelectric conversion of the cell structure of this embodiment, light is incident on the back side 1b of the silicon substrate 1 along the direction of the third silicon nitride layer 53, the second silicon nitride layer 52, and the first silicon nitride layer 51. The reflectivity of the third nitride layer is the smallest. In this way, the light reflected by the first anti-reflection layer 5 increases the amount of light incident on the silicon substrate 1, thereby increasing the photoelectric conversion efficiency of the cell structure. The light passes through the third silicon nitride layer 53, the second silicon nitride layer 52, and the first silicon nitride layer 51, and the refractive index increases in sequence, converting more light obliquely incident on the back side 1b of the silicon substrate 1 into vertical incident light, thereby increasing the amount of light vertically incident on the silicon substrate 1, further increasing the photoelectric conversion efficiency of the cell structure.

In the battery structure of this embodiment, the first passivation layer 4 is arranged between the first anti-reflection layer 5 and the first semiconductor doping layer 3, so as to improve the passivation effect of the back side 1b of the silicon substrate 1. At the same time, the first passivation layer 4 enhances the bonding strength between the first anti-reflection layer 5 and the first semiconductor doping layer 3, so as to prevent the first anti-reflection layer 5 from falling off. At the same time, when the battery structure is in a heated state or in a high-temperature environment, the hydrogen ions in the first anti-reflection layer 5 diffuse outward and may generate bubbles, especially the hydrogen ions in the first silicon nitride layer 51 diffuse in the direction of the first semiconductor doping layer 3 and generate bubbles. The first passivation layer 4 has good high-temperature stability, and can isolate the bubbles generated by the first silicon nitride layer 51, so as to prevent the bubbles from squeezing the first semiconductor doping layer 3 and causing the first semiconductor doping layer 3 to fall off, thereby improving the structural stability and working stability of the film layer on the back side 1b of the silicon substrate 1.

In some embodiments, as shown in Figures 1, 2 or 3, as shown in Figure 3, the battery structure also includes an emitter 6 and a second passivation layer 7, the emitter 6 is located on the front side 1a of the silicon substrate 1, the emitter 6 has a P-type conductivity type, the emitter 6 and the substrate 1 form a PN junction, the second passivation layer 7 covers the top surface of the emitter 6, and the contact surface of the second passivation layer 7 and the emitter 6 forms an ohmic contact.

In some embodiments, as shown in FIG3 , the second passivation layer 7 at least includes an aluminum oxide layer 71 disposed on the top surface of the emitter 6 and connected to the top surface of the emitter 6. The second passivation layer 7 may also include a silicon nitride passivation layer 72, a silicon oxynitride passivation layer 73, and a silicon oxide passivation layer 74 stacked on the aluminum oxide layer 71. The front and back sides of the battery structure of this embodiment have good passivation effect and light transmittance, the first passivation layer 4 and the first anti-reflection layer 5 form good protection for the back side of the battery structure, and the second passivation layer 7 forms good protection for the front side of the battery structure, thereby improving the surface passivation effect of the battery structure.

In some embodiments, as shown in FIG. 1, FIG. 2 or FIG. 3, the battery structure further includes a plurality of front gate electrodes 101 located on the side of the second passivation layer 7 away from the substrate 1, and the front gate electrodes 101 are in contact with the emitter 6 through the second passivation layer 7. The material of the front gate electrodes 101 may include silver or aluminum.

In some embodiments, as shown in FIG. 1, FIG. 2 or FIG. 3, the cell structure further includes a plurality of back gate electrodes 201 located on the side of the first anti-reflection layer 5 away from the substrate 1, the back gate electrodes 201 penetrate the first anti-reflection layer 5 and the first passivation layer 4 and extend into the first semiconductor doping layer 3, and the back gate electrodes 201 contact the first semiconductor doping layer 3 through the first anti-reflection layer 5, the first passivation layer 4 and the first semiconductor doping layer 3. The material of the back gate electrodes 201 may include silver or aluminum.

According to an exemplary embodiment, a photovoltaic module is provided. The photovoltaic module includes the cell structure in the above embodiment. The photovoltaic module of this embodiment has good passivation effect and photoelectric conversion efficiency.

The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features of the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims (10)

1. A battery structure, characterized by comprising:

A silicon substrate comprising a front side and a back side;

a tunneling layer covering the back surface of the silicon substrate;

The first semiconductor doping layer covers the bottom surface of the tunneling layer;

a first passivation layer covering a bottom surface of the first semiconductor doped layer, the first passivation layer including a silicon oxide layer;

And the first antireflection layer covers the bottom surface of the first passivation layer and comprises at least one silicon nitride layer.

2. The cell structure of claim 1, wherein the refractive index of the first anti-reflective layer is greater than the refractive index of the first passivation layer.

3. The cell structure of claim 1, wherein the refractive index of at least one of the silicon nitride layers decreases gradually in a direction away from the first passivation layer.

4. The cell structure of claim 1 wherein at least one of said silicon nitride layers is doped with hydrogen ions, the doping concentration of hydrogen ions in at least one of said silicon nitride layers decreasing in a direction away from said first passivation layer.

5. The cell structure of claim 3 or 4, wherein the first anti-reflection layer comprises a first silicon nitride layer, a second silicon nitride layer, and a third silicon nitride layer stacked on a bottom surface of the first passivation layer.

6. The cell structure of claim 3 or 4, wherein the first passivation layer has a thickness of 3nm-4nm.

7. The battery structure of claim 1, wherein the battery structure further comprises:

the emitter is positioned on the front surface of the silicon substrate;

And the second passivation layer covers the top surface of the emitter, and the contact surface of the second passivation layer and the emitter forms ohmic contact.

8. The cell structure of claim 7, wherein the second passivation layer comprises at least an aluminum oxide layer disposed on and coupled to the top surface of the emitter.

9. The battery structure of claim 7, wherein the first semiconductor doped layer has an N-type conductivity and the emitter has a P-type conductivity.

10. A photovoltaic module comprising the cell structure of any one of claims 1-9.