CN114122157B - Photovoltaic cell and its manufacturing method, photovoltaic module - Google Patents

Abstract

The embodiment of the application relates to the field of solar energy, and provides a photovoltaic cell, a manufacturing method thereof and a photovoltaic module, wherein the photovoltaic cell comprises: a substrate; a first anti-reflection layer positioned on one side of the substrate; the second antireflection layer is positioned on one side, far away from the substrate, of the first antireflection layer, the first antireflection layer comprises a first silicon oxynitride material, the second antireflection layer comprises a second silicon oxynitride material, and in the direction perpendicular to the direction of the first antireflection layer pointing to the second antireflection layer, the content ratio of oxygen elements and nitrogen elements of one of the first antireflection layer and the second antireflection layer tends to increase, and the content ratio of oxygen elements and nitrogen elements of the other one tends to decrease. The embodiment of the application is at least beneficial to improving the absorptivity of the photovoltaic cell to light incident on the photovoltaic cell.

Description

Photovoltaic cell and its manufacturing method, photovoltaic module

technical field

The embodiments of the present application relate to the field of solar energy, and in particular, to a photovoltaic cell, a method for manufacturing the same, and a photovoltaic assembly.

Background technique

The reflectivity or absorption rate of photovoltaic cells to sunlight is a key factor affecting the photoelectric conversion efficiency of photovoltaic cells. At present, single-layer silicon nitride, multi-layer silicon nitride, or a stacked structure of silicon nitride and other material films are often used as anti-reflection structures in photovoltaic cells in the industry.

However, the silicon nitride film has a large internal stress, and during the process of preparing the silicon nitride film, due to the existence of hydrogen, more defects will be generated in the silicon nitride film, which will reduce the nitrogen The light absorption rate of the silicon oxide film layer is reduced, thereby reducing the light absorption rate of the photovoltaic cell.

SUMMARY OF THE INVENTION

Embodiments of the present application provide a photovoltaic cell, a method for manufacturing the same, and a photovoltaic assembly, which are at least conducive to improving the light absorption rate of the photovoltaic cell.

According to some embodiments of the present application, one aspect of the embodiments of the present application provides a photovoltaic cell, comprising: a substrate; a first anti-reflection layer located on one side of the substrate; and a second anti-reflection layer located on the first anti-reflection layer The side of the layer away from the substrate, the first anti-reflection layer includes a first silicon oxynitride material, the second anti-reflection layer includes a second silicon oxynitride material, and the direction is perpendicular to the first anti-reflection layer. In the direction of the direction of the second anti-reflection layer, the content ratio of oxygen element and nitrogen element in one of the first anti-reflection layer and the second anti-reflection layer shows an increasing trend, and the oxygen element in the other The content ratio of nitrogen and nitrogen showed a decreasing trend.

In some embodiments, the content ratio of oxygen element and nitrogen element in the first anti-reflection layer is not greater than 0.9, and the content ratio of oxygen element and nitrogen element in the second anti-reflection layer is not greater than 0.9.

In some embodiments, the first silicon oxynitride material is a mixture of silicon oxide and silicon nitride, and the second silicon oxynitride material is a mixture of silicon oxide and silicon nitride. In the direction in which the reflective layer points to the direction of the second anti-reflection layer, the content ratio of silicon oxide and silicon nitride in one of the first anti-reflection layer and the second anti-reflection layer tends to increase, and the other The content ratio of silicon oxide and silicon nitride in the former showed a decreasing trend.

In some embodiments, the content ratio of silicon oxide and silicon nitride in the first anti-reflection layer ranges from 0 to 1, and the content ratio of silicon oxide and silicon nitride in the second anti-reflection layer ranges from 0 to 1. 0~1.

In some embodiments, in a direction perpendicular to the direction of the first anti-reflection layer pointing to the second anti-reflection layer, the oxygen element of one of the first anti-reflection layer and the second anti-reflection layer The content of the oxygen element shows an increasing trend, and the oxygen element content of the other one shows a decreasing trend, and the content ratio of the oxygen element to the silicon element in the first anti-reflection layer and the second anti-reflection layer is not greater than 0.5.

In some embodiments, in a direction perpendicular to the direction of the first anti-reflection layer pointing to the second anti-reflection layer, the nitrogen element of one of the first anti-reflection layer and the second anti-reflection layer The content is increasing, and the nitrogen content of the other is decreasing, and the content ratio of oxygen element and silicon element in the first anti-reflection layer and the second anti-reflection layer varies from 1.05 to 1.33.

In some embodiments, along the direction from the first anti-reflection layer to the second anti-reflection layer, the thickness of the first anti-reflection layer is 30 nm˜50 nm, and the thickness of the second anti-reflection layer is 30nm~50nm.

In some embodiments, the refraction of one of the first anti-reflection layer and the second anti-reflection layer is in a direction perpendicular to the direction of the first anti-reflection layer pointing to the second anti-reflection layer The refractive index of the first anti-reflection layer and the second anti-reflection layer shows a decreasing trend first and then an increasing trend.

In some embodiments, the maximum value of the refractive index of the first anti-reflection layer and the refractive index of the second anti-reflection layer is 1.9˜2.1, and the refractive index of the first anti-reflection layer and the second The minimum value of the refractive index of the antireflection layer is 1.4 to 1.6.

In some embodiments, the highest value of the refractive index of the first anti-reflection layer is the same as the highest value of the refractive index of the second anti-reflection layer, and the lowest value of the refractive index of the first anti-reflection layer is the same as the highest value of the refractive index of the second anti-reflection layer The minimum value of the refractive index of the antireflection layer is the same.

According to some embodiments of the present application, another embodiment of the present application further provides a method for manufacturing a photovoltaic cell, comprising: providing a substrate; forming a first anti-reflection layer on one side of the substrate; and forming a first anti-reflection layer on the first anti-reflection layer A second anti-reflection layer is formed on a side of the layer away from the substrate, the first anti-reflection layer includes a first silicon oxynitride material, and the second anti-reflection layer includes a second silicon oxynitride material, along the direction perpendicular to the The first anti-reflection layer points to the direction of the second anti-reflection layer, and the content ratio of oxygen and nitrogen in one of the first anti-reflection layer and the second anti-reflection layer tends to increase, On the other hand, the content ratio of oxygen and nitrogen showed a decreasing trend.

In some embodiments, the method for manufacturing a photovoltaic cell further includes: providing a cavity, and in a direction perpendicular to the direction of the first anti-reflection layer pointing to the second anti-reflection layer, the cavity is sequentially arranged on the cavity a first air inlet and a second air inlet, and the air intake directions of the first air inlet and the second air inlet are opposite, and the base is located at the first air inlet and the second air inlet between the air inlets; the step of forming the first anti-reflection layer in the chamber includes: depositing a silicon nitride material on one side of the substrate, and during the deposition process, opening the first air inlet and closing the second air inlet; the step of forming the second anti-reflection layer in the chamber includes: depositing a silicon nitride material on the side of the first anti-reflection layer away from the substrate, and During the deposition process, the first air inlet is closed and the second air inlet is opened; in the step of forming the first anti-reflection layer and the step of forming the second anti-reflection layer, the first The gas provided by the gas inlet and the second gas inlet is gas containing at least oxygen element.

In some embodiments, the gas containing at least elemental oxygen includes oxygen or nitrous oxide.

In some embodiments, the first gas inlet and the second gas inlet provide the same gas.

In some embodiments, the gas flow rate of the gas provided by the first air inlet is not higher than 150 mL/s, and the gas flow rate of the gas provided by the second air inlet is not higher than 150 mL/s.

According to some embodiments of the present application, another aspect of the embodiments of the present application further provides a photovoltaic module, comprising: a battery string formed by connecting the photovoltaic cells described in any one of the above, or by the manufacturing method described in any one of the above The manufactured photovoltaic cells are connected and formed; an encapsulating adhesive film is used to cover the surface of the battery string; a cover plate is used to cover the surface of the encapsulating adhesive film facing away from the battery string.

The technical solutions provided by the embodiments of the present application have at least the following advantages:

A first anti-reflection layer and a second anti-reflection layer are stacked on the substrate, and along the direction perpendicular to the direction of the first anti-reflection layer to the second anti-reflection layer, the first anti-reflection layer and the second anti-reflection layer are designed The content of oxygen element and nitrogen element changes gradually, so that the content ratio of oxygen element and nitrogen element in the first anti-reflection layer and the second anti-reflection layer gradually changes, then the direction perpendicular to the first anti-reflection layer is directed to the second anti-reflection layer In the direction of the direction, the size of the refractive index of the first anti-reflection layer and the second anti-reflection layer to light gradually changes, and the change trend of the size of the refractive index of the first anti-reflection layer and the second anti-reflection layer to light is different, Therefore, it is beneficial to increase the probability of total reflection of light in the first anti-reflection layer and the second anti-reflection layer, and reduce the incidence of light entering the first anti-reflection layer and the second anti-reflection layer through one or more refractions. The probability of being in the air, thereby greatly reducing the loss of light incident on the photovoltaic module, and improving the absorption rate of the photovoltaic module to the light incident on the photovoltaic module.

Description of drawings

One or more embodiments are exemplified by the pictures in the corresponding drawings, and these exemplifications do not constitute limitations of the embodiments, and elements with the same reference numerals in the drawings are denoted as similar elements, Unless otherwise stated, the figures in the accompanying drawings do not constitute a scale limitation.

FIG. 1 is a schematic structural diagram of a photovoltaic cell according to an embodiment of the present application;

2 to 5 are schematic diagrams of four propagation paths of light incident on the second anti-reflection layer provided by an embodiment of the present application;

6 is a graph showing the change of the refractive index of the first anti-reflection layer or the second anti-reflection layer as the material composition of the first anti-reflection layer or the second anti-reflection layer changes according to an embodiment of the present application;

7 to 8 are schematic structural diagrams corresponding to each step of a method for manufacturing a photovoltaic cell according to another embodiment of the present application;

FIG. 9 is a schematic structural diagram of a photovoltaic module provided by another embodiment of the present application.

Detailed ways

It can be known from the background art that the light absorption rate of photovoltaic cells needs to be improved.

An embodiment of the present application provides a photovoltaic cell, in a direction perpendicular to the direction from the first anti-reflection layer to the second anti-reflection layer, the content of oxygen and nitrogen in one of the first anti-reflection layer and the second anti-reflection layer The ratio shows an increasing trend, and the content ratio of the other oxygen element and nitrogen element shows a decreasing trend. In this way, along the direction perpendicular to the direction of the first anti-reflection layer to the second anti-reflection layer, it is beneficial to make the first anti-reflection layer. Both the reflective layer and the second anti-reflection layer will exhibit a gradual change in the refractive index of light, and the change trend of the refractive index of the first anti-reflection layer and the second anti-reflection layer to light is different, which is conducive to increasing the size of the refractive index of light. The probability of total reflection of light in the first anti-reflection layer and the second anti-reflection layer, and the probability of reducing the probability of light incident on the first anti-reflection layer and the second anti-reflection layer being refracted one or more times into the air , so as to greatly reduce the loss of light incident on the photovoltaic module, and improve the absorption rate of the photovoltaic module to the light incident on the photovoltaic module.

The embodiments of the present application will be described in detail below with reference to the accompanying drawings. However, those of ordinary skill in the art can understand that, in the embodiments of the present application, many technical details are provided for the reader to better understand the embodiments of the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in the embodiments of the present application can be implemented.

An embodiment of the present application provides a photovoltaic cell, and the photovoltaic cell provided by an embodiment of the present application will be described in detail below with reference to the accompanying drawings. 1 is a schematic structural diagram of a photovoltaic cell provided by an embodiment of the present application; FIGS. 2 to 5 are schematic diagrams of four propagation routes of light incident on the second anti-reflection layer provided by an embodiment of the present application; An embodiment of the present application provides a graph of the change in the refractive index of the first anti-reflection layer or the second anti-reflection layer with the change of the material composition of the first anti-reflection layer or the second anti-reflection layer. It should be noted that, for the convenience of illustration, the structures of the emitter, the tunneling film, the passivation film and the electrode in the photovoltaic cell are not shown in FIGS. 1 to 5 .

1 to 5 , the photovoltaic cell includes: a substrate 100 ; a first anti-reflection layer 101 located on one side of the substrate 100 ; Wherein, along the direction X perpendicular to the direction of the first anti-reflection layer 101 to the second anti-reflection layer 102, the refractive index of one of the first anti-reflection layer 101 and the second anti-reflection layer 102 increases, and the other The refractive index of one of them is decreasing, and the difference between the refractive indices of the first anti-reflection layer 101 and the second anti-reflection layer 102 is first decreasing and then increasing.

It can be understood that, in some embodiments, the increasing trend of a certain parameter means that the parameter gradually increases, that is, in the changing process, the parameter is always increasing gradually; a certain parameter has a decreasing trend. It means that the parameter gradually decreases, that is, in the process of change, the parameter has been gradually decreasing. In other embodiments, the increasing trend of a certain parameter means that in the process of change, the parameter increases as a whole, and in the process of local change, the parameter may gradually decrease; A decreasing trend of a parameter means that in the process of change, the parameter is in a state of decreasing as a whole, and in a local process of change, the parameter may be in a state of increasing gradually. In other embodiments, the increasing trend of a certain parameter may be that the parameter gradually increases, the decreasing trend of a certain parameter may be that the overall decreasing trend, and in the local change process, the parameter is gradually increasing Or, a parameter showing an increasing trend may be an overall increase, and in the local change process, the parameter is gradually decreasing, and a parameter showing a decreasing trend refers to the parameters gradually decrease.

For example, in some embodiments, the index of refraction of one of the first anti-reflection layer 101 and the second anti-reflection layer 102 tends to increase, which means: the first anti-reflection layer 101 and the second anti-reflection layer 102 The refractive index of one of them gradually increases; that is, during the change process, the refractive index of one of the first anti-reflection layer 101 and the second anti-reflection layer 102 is always in a state of increasing gradually; the first anti-reflection layer 101 The decreasing trend of the refractive index of one of the first anti-reflection layer 101 and the second anti-reflection layer 102 means that the refractive index of one of the first anti-reflection layer 101 and the second anti-reflection layer 102 gradually decreases, that is, during the change process Among them, the refractive index of one of the first anti-reflection layer 101 and the second anti-reflection layer 102 is always in a state of gradually decreasing. In some other embodiments, the fact that the refractive index of one of the first anti-reflection layer 101 and the second anti-reflection layer 102 has an increasing trend refers to that during the change process, the refractive index increases as a whole, During the local change process, the refractive index may be in a state of gradually decreasing; the decreasing trend of the refractive index of one of the first anti-reflection layer 101 and the second anti-reflection layer 102 means that: during the change process , the refractive index is in a state of decreasing as a whole, and in a local change process, the refractive index may be in a state of increasing gradually. In other embodiments, the increasing trend of the refractive index may be that the refractive index gradually increases, the decreasing trend of the refractive index may be that the refractive index is decreasing as a whole, and in the local change process, the refractive index is gradually increasing Or, the index of refraction shows an increasing trend, which can be an overall increase. In the process of local changes, the index of refraction is gradually reduced, and the decreasing trend of the index of rate gradually decreases.

It should be noted that if there are stacked first dielectric layers and second dielectric layers, and the refractive index of the first dielectric layer is lower than that of the second dielectric layer, the first dielectric layer has a critical value relative to the second dielectric layer. Angle, when light is incident from the second medium layer with higher refractive index to the first medium layer with lower refractive index, if the incident angle of the light traveling to the contact between the second medium layer and the first medium layer is greater than or equal to At this critical angle, the refracted rays will disappear, and all the incident rays will be reflected into the second dielectric layer without being refracted into the first dielectric layer, an optical phenomenon called total internal reflection (TIR). Among them, in the phenomenon of total reflection, the light is just totally reflected, that is, the incident angle of the light when the refraction angle of the light is 90 degrees is the critical angle. In some embodiments, the first dielectric layer may include an anti-reflection layer and/or a passivation layer, and the second dielectric layer may include an anti-reflection layer and/or a passivation layer.

In addition, the greater the difference between the refractive index of the first dielectric layer and the refractive index of the second dielectric layer, the smaller the critical angle of the first dielectric layer relative to the second dielectric layer, and the light propagates from the second dielectric layer to the second dielectric layer. In the process of one dielectric layer, the phenomenon of total reflection is more likely to occur, that is, the more easily the light is reflected in the second dielectric layer, and the less likely it is refracted into the first dielectric layer.

Wherein, along the direction X, the difference in refractive index between the first anti-reflection layer 101 and the second anti-reflection layer 102 firstly decreases and then increases, so along the direction X, the first anti-reflection layer 101 The critical angle at the interface in contact with the second anti-reflection layer 102 will first increase and then decrease. It can be understood that the critical angle at the interface between the first anti-reflection layer 101 and the second anti-reflection layer 102 is the critical angle of the first anti-reflection layer 101 relative to the second anti-reflection layer 102 at the interface. It should be noted that the foregoing has described in detail about the "increasing trend", "the specific situation included in the increasing trend", "the decreasing trend" and "the specific situation included in the decreasing trend". The related description that the difference in refractive index is increasing and the description that the difference in refractive index is decreasing will not be repeated here.

Under the above premise, the case where light is incident from the side of the second anti-reflection layer 102 away from the first anti-reflection layer 101 and propagates in the second anti-reflection layer 102 , the first anti-reflection layer 101 and the substrate 100 in sequence can be divided into The following four situations:

It should be noted that, in order to facilitate the subsequent description, in FIGS. 2 to 5 , along the direction X, the change trend of the refractive index of the first anti-reflection layer 101 is from low to high, and the refraction of the second anti-reflection layer 102 The change trend of the refractive index is from high to low as an example. In practical applications, along the direction X, the change trend of the refractive index of the first anti-reflection layer 101 can be from high to low. The changing trend of the size of the refractive index can be from low to high.

Case 1: Referring to FIG. 2 , the light is incident on the second anti-reflection layer 102 where the refractive index is higher, and the light is incident from the second anti-reflection layer 102 to the second anti-reflection layer 102 and the first anti-reflection layer 101 for the first time At the contact position A, the incident angle of the light at A is β, and the critical angle of the first anti-reflection layer 101 relative to the second anti-reflection layer 102 at A is less than or equal to the incident angle β.

Since the incident angle β is greater than or equal to the critical angle of the first anti-reflection layer 101 relative to the second anti-reflection layer 102 at A, the light will be totally reflected in the second anti-reflection layer 102 . Along the direction X, the refractive index of the first anti-reflection layer 101 shows an increasing trend, and the refractive index of the second anti-reflection layer 102 shows a decreasing trend, so the refractive index of the first anti-reflection layer 101 and the second anti-reflection layer 102 The difference between the refractive indices of the first anti-reflection layer 101 and the second anti-reflection layer 102 will tend to decrease, so that the critical angle at the contact point between the first anti-reflection layer 101 and the second anti-reflection layer 102 will tend to increase. After sub-total reflection, for example, when light is incident from the second anti-reflection layer 102 to the position B where the second anti-reflection layer 102 is in contact with the first anti-reflection layer 101, the incident angle β is smaller than that of the first anti-reflection layer 101 at B Relative to the critical angle of the second anti-reflection layer 102 , the light in the second anti-reflection layer 102 is refracted into the first anti-reflection layer 101 .

When the light is refracted at B, it enters the first anti-reflection layer 101 with a low refractive index from the second anti-reflection layer 102 with a high refractive index, and the refraction angle Ψ is greater than the incident angle β. The critical angle at the contact point between the reflection layer 101 and the second anti-reflection layer 102 first increases and then decreases, so in the subsequent propagation process of the light, it propagates from the first anti-reflection layer 101 to the first anti-reflection layer 101 again. When the anti-reflection layer 101 is in contact with the second anti-reflection layer 102, it is beneficial to make the incident angle Ψ here greater than the critical angle between the first anti-reflection layer 101 and the second anti-reflection layer 102, so the light Total reflection easily occurs in the first anti-reflection layer 101 , and it is not easy to be refracted into the second anti-reflection layer 102 . In addition, along the direction X, when the light in the second anti-reflection layer 102 is incident on the contact point between the first anti-reflection layer 101 and the second anti-reflection layer 102 after the point B, it is also beneficial to make the incident angle Ψ here. If the angle is greater than the critical angle between the first anti-reflection layer 101 and the second anti-reflection layer 102 , light is likely to be totally reflected in the first anti-reflection layer 101 and not easily refracted into the second anti-reflection layer 102 . It should be noted that the foregoing has described in detail about the “increasing trend” and the specific situations included in the “increasing trend”, and here the relevant description of the critical angle showing an increasing trend and the critical angle showing a decreasing trend The relevant descriptions are not repeated.

It can be seen from the above analysis that, in case 1, most of the light incident from the side of the second anti-reflection layer 102 away from the first anti-reflection layer 101 is totally reflected in the second anti-reflection layer 102 and the first anti-reflection layer 101 in turn. , and finally fully absorbed by the substrate 100 , reducing the probability that the light incident into the photovoltaic cell will eventually propagate to the outside of the photovoltaic cell, thereby helping to improve the light absorption rate of the photovoltaic cell.

Case 2: Referring to FIG. 3 , the light is incident on the second anti-reflection layer 102 where the refractive index is higher, and the light is incident from the second anti-reflection layer 102 to the second anti-reflection layer 102 and the first anti-reflection layer 101 for the first time At the contact position A, the incident angle of the light at A is β, and the critical angle of the first anti-reflection layer 101 relative to the second anti-reflection layer 102 at A is greater than the incident angle β.

Since the incident angle β is smaller than the critical angle of the first anti-reflection layer 101 relative to the second anti-reflection layer 102 at A, the light will be reflected and refracted in the second anti-reflection layer 102, that is, part of the light will be reflected from the second anti-reflection layer 102. The layer 102 is refracted into the first anti-reflection layer 101 . Part of the light refracted into the first anti-reflection layer 101 will be directly absorbed by the substrate 100 , and part of the light will be reflected to the contact point between the first anti-reflection layer 101 and the second anti-reflection layer 102 , for example, at C.

From the change trend of the refractive index of the first anti-reflection layer 101 and the change trend of the refractive index of the second anti-reflection layer 102, it can be known that the difference between the refractive indices between the first anti-reflection layer 101 and the second anti-reflection layer 102 at C is The difference is smaller than the difference in refractive index between the first anti-reflection layer 101 and the second anti-reflection layer 102 at A. As the light propagates from the first anti-reflection layer 101 to the second anti-reflection layer 102, the refractive index difference between the first anti-reflection layer 101 and the second anti-reflection layer 102 becomes smaller and smaller, and the refraction angle becomes smaller and smaller. The smaller, that is, the difference between the angle Ψ and the angle β is greater than the difference between the angle Ψ and the angle δ, the refraction angle δ at C is greater than the incident angle β at A, which is beneficial to increase the angle δ to be greater than the second anti-reflection The probability of the critical angle between the layer 102 and the air is beneficial to reduce the probability of light refracting from the second anti-reflection layer 102 into the air, so as to improve the incident light passing through the first anti-reflection layer 101 and the second anti-reflection layer 102 The probability of reflection and refraction entering into the substrate 100 is favorable to improve the light absorption rate of the photovoltaic cell.

Case 3: Referring to FIG. 4 , the light is incident on the lower refractive index of the second anti-reflection layer 102 , and the light is incident from the first anti-reflection layer 101 to D where the first anti-reflection layer 101 is in contact with the substrate 100 for the first time. When the angle of incidence of light at D is Ψ, the critical angle of the second anti-reflection layer 102 relative to the first anti-reflection layer 101 at E is less than or equal to the incident angle Ψ.

Case 4: Referring to FIG. 5 , the light is incident on the place where the refractive index of the second anti-reflection layer 102 is lower, and the light is incident from the first anti-reflection layer 101 to D where the first anti-reflection layer 101 is in contact with the substrate 100 for the first time. When the angle of incidence of light at D is Ψ, the critical angle of the second anti-reflection layer 102 relative to the first anti-reflection layer 101 at E is greater than the incident angle Ψ.

For cases 3 and 4, light is refracted from the air into the second anti-reflection layer 102. Since the refractive index of the second anti-reflection layer 102 is lower than the refractive index of the first anti-reflection layer 101, the light is bound to be refracted from the second anti-reflection layer 101. The reflection layer 102 is refracted into the first anti-reflection layer 101, no matter if the critical angle of the second anti-reflection layer 102 relative to the first anti-reflection layer 101 at E is less than or equal to the incident angle Ψ in the third case, the light will After a period of total reflection in the first anti-reflection layer 101, it will not be refracted into the second anti-reflection layer 102 and then absorbed by the substrate 100. As in the fourth case, the second anti-reflection layer 102 is at E relative to the first anti-reflection layer 102. The critical angle of the reflection layer 101 is greater than the incident angle Ψ, and at the contact point between the first anti-reflection layer 101 and the second anti-reflection layer 102, part of the light is reflected into the first anti-reflection layer 101, and then from the first anti-reflection layer 102. 101 into the substrate 100. It can be seen that in the third and fourth cases, most of the light will propagate into the substrate 100, and along the direction parallel to and opposite to the direction X, the difference in refractive index between the substrate 100 and the first anti-reflection layer 101 increases The general trend is that the critical angle between the substrate 100 and the first anti-reflection layer 101 tends to decrease, which is beneficial to increase the probability of total reflection of light in the substrate 100 and reduce the refraction of light from the substrate 100 and finally enter the air Therefore, the loss of light incident on the photovoltaic module is greatly reduced, and the absorption rate of the photovoltaic module to light is improved.

In addition, in case 3, when the light propagates into the substrate 100, the refractive index of the first anti-reflection layer 101 tends to decrease along the propagation direction of the light, that is, along the direction parallel to the direction X and opposite to the direction X , that is, the difference between the refractive index of the substrate 100 and the refractive index of the first anti-reflection layer 101 tends to increase, and the probability of light being refracted from the substrate 100 into the first anti-reflection layer 101 is getting smaller and smaller, which is beneficial to reduce the propagation The probability that light entering a photovoltaic cell will re-transmit into the air. In case 4, at the contact point between the first anti-reflection layer 101 and the second anti-reflection layer 102, although part of the light will be refracted from the first anti-reflection layer 101 into the second anti-reflection layer 102, due to the direction of In the direction parallel to X and opposite to the direction X, the refractive index of the second anti-reflection layer 102 tends to increase, and the probability of light being refracted into the air from the second anti-reflection layer 102 becomes smaller and smaller, which is beneficial to Reduces the probability of light propagating into the photovoltaic cell re-propagating into the air.

From the analysis of the above four cases, it can be seen that the design of one of the first anti-reflection layer 101 and the second anti-reflection layer 102 along the direction X perpendicular to the direction of the first anti-reflection layer 101 to the second anti-reflection layer 102 The refractive index is increasing, the refractive index of the other is decreasing, and the difference between the refractive indices of the first anti-reflection layer 101 and the second anti-reflection layer 102 is first decreasing and then increasing. The battery is beneficial to increase the probability of total reflection of light in the first anti-reflection layer 101 and/or the second anti-reflection layer 102 and/or the substrate 100, and reduce the light in the first anti-reflection layer 101 and/or the second anti-reflection layer 101. The probability of the anti-reflection layer 102 and/or the substrate 100 being refracted one or more times into the air greatly reduces the loss of light incident on the photovoltaic module and improves the light absorption rate of the photovoltaic module.

In some embodiments, the maximum value of the refractive index of the first anti-reflection layer 101 and the refractive index of the second anti-reflection layer 102 is 1.9˜2.1, and the refractive index of the first anti-reflection layer 101 and the second anti-reflection layer 102 The minimum value of the refractive index is 1.4˜1.6, that is, the variation range of the maximum value of the refractive index of the first anti-reflection layer 101 is the same as the variation range of the maximum value of the refractive index of the second anti-reflection layer 102 . The variation range of the minimum value of the refractive index of α is the same as the variation range of the minimum value of the refractive index of the second anti-reflection layer 102 . In this way, it is beneficial to avoid that the difference between the refractive indices of the first anti-reflection layer 101 and the second anti-reflection layer 102 is too large, and avoid excessive total reflection times of light in the first anti-reflection layer 101 or the second anti-reflection layer 102 , causing unnecessary light loss, which is beneficial to improve the probability of light propagating into the substrate 100 , so as to improve the light absorption rate of the substrate 100 .

In some embodiments, the highest value of the refractive index of the first anti-reflection layer 101 is the same as the highest value of the refractive index of the second anti-reflection layer 102 , and the lowest value of the refractive index of the first anti-reflection layer 101 is the same as the highest value of the refractive index of the second anti-reflection layer 102 The lowest values of refractive index are the same. In this way, along the direction X, it is beneficial to control the amplitude of the gradient of the refractive index of the first anti-reflection layer 101 from the lowest value to the highest value is consistent with the amplitude of the gradient of the refractive index of the second anti-reflection layer 102 from the highest value to the lowest value, thereby It is beneficial to make the change of the difference between the refractive indices of the first anti-reflection layer 101 and the second anti-reflection layer 102 more gradual. The difference between the refractive indices of the reflective layer 101 and the second anti-reflection layer 102 is almost zero. Along the direction X, the difference between the refractive indices of the first anti-reflection layer 101 and the second anti-reflection layer 102 decreases firstly and then decreases. When the difference between the refractive indices of the first anti-reflection layer 101 and the second anti-reflection layer 102 is zero, the difference between the refractive indices of the first anti-reflection layer 101 and the second anti-reflection layer 102 increases gradually. In addition, the change of the difference between the refractive indices of the first anti-reflection layer 101 and the second anti-reflection layer 102 is more gradual, which is beneficial to further reduce the probability of light being refracted from the photovoltaic cell into the air, thereby further improving the light efficiency of the photovoltaic cell. Absorption rate.

In some embodiments, the highest value of the refractive index of the first anti-reflection layer 101 and the refractive index of the second anti-reflection layer 102 may both be 2.1, and the refractive index of the first anti-reflection layer 101 and the second anti-reflection layer 102 The lowest value of the refractive index can be 1.5.

In some embodiments, along the direction X perpendicular to the direction of the first anti-reflection layer 101 to the second anti-reflection layer 102, the first anti-reflection layer 101 includes a first silicon oxynitride material, and the second anti-reflection layer 102 includes a first anti-reflection layer 102. In the silicon oxynitride material, the content ratio of oxygen and nitrogen in one of the first anti-reflection layer 101 and the second anti-reflection layer 102 is increasing, and the content ratio of oxygen and nitrogen in the other is decreasing. Small trend. Since the higher the content ratio of oxygen and nitrogen in the silicon oxynitride material, the lower the refractive index of the silicon oxynitride material, along the direction X, due to the change in the content ratio of oxygen and nitrogen in the silicon oxynitride material, The refractive index of one of the first anti-reflection layer 101 and the second anti-reflection layer 102 tends to increase, and the refractive index of the other tends to decrease. It should be noted that the foregoing has described in detail about the "increasing trend", "the specific situation included in the increasing trend", "the decreasing trend" and "the specific situation included in the decreasing trend". The related description that the content ratio of oxygen element and nitrogen element shows an increasing trend and the related description that the content ratio of oxygen element and nitrogen element shows a decreasing trend will not be repeated here. It should be noted that, in order to facilitate the subsequent description, along the direction X, the content ratio of oxygen element and nitrogen element in the first anti-reflection layer 101 tends to decrease, and the content ratio of oxygen element and nitrogen element in the second anti-reflection layer 102 It is an example that the content ratio shows an increasing trend, that is, along the direction X, the refractive index of the first anti-reflection layer 101 shows an increasing trend, and the refractive index of the second anti-reflection layer 102 shows a decreasing trend. In practical applications, along the direction On X, it may be that the content ratio of oxygen element and nitrogen element in the first anti-reflection layer 101 tends to increase, and the content ratio of oxygen element and nitrogen element in the second anti-reflection layer 102 tends to decrease.

In some embodiments, the first anti-reflection layer 101 includes a first silicon oxynitride material, the second anti-reflection layer 102 includes a second silicon oxynitride material, and the direction perpendicular to the first anti-reflection layer 101 is directed to the second anti-reflection layer 102 In the direction X of the direction, the oxygen element content of one of the first anti-reflection layer 101 and the second anti-reflection layer 102 tends to increase, and the oxygen element content of the other tends to decrease, and the first anti-reflection layer 101 and the content ratio of oxygen element and silicon element in the second anti-reflection layer 102 is not greater than 0.5, so it is beneficial to further ensure that the refractive index of the first anti-reflection layer 101 and the refractive index of the second anti-reflection layer 102 have opposite changing trends . In one example, the content ratio of oxygen element to silicon element in the first anti-reflection layer 101 and the second anti-reflection layer 102 is not greater than 0.43. It should be noted that the foregoing has described in detail about the "increasing trend", "the specific situation included in the increasing trend", "the decreasing trend" and "the specific situation included in the decreasing trend". The related description of the increasing trend of the oxygen element content and the related description of the decreasing trend of the oxygen element content will not be repeated here.

It should be noted that, in the embodiment of the present disclosure, “along the direction X, the content of oxygen in the first anti-reflection layer 101 tends to decrease, so that the content ratio of oxygen and nitrogen in the first anti-reflection layer 101 is shows a decreasing trend, so that the refractive index of the first anti-reflection layer 101 shows an increasing trend; the content of oxygen in the second anti-reflection layer 102 shows an increasing trend, so that the oxygen and nitrogen in the second anti-reflection layer 102 The content ratio of the elements tends to increase, so that the refractive index of the second anti-reflection layer 102 tends to decrease” as an example. In practical applications, along the direction X, it can be: oxygen in the first anti-reflection layer 101 The element content tends to increase, and the oxygen element content in the second anti-reflection layer 102 tends to decrease.

In some embodiments, the first anti-reflection layer 101 includes a first silicon oxynitride material, the second anti-reflection layer 102 includes a second silicon oxynitride material, and the direction perpendicular to the first anti-reflection layer 101 is directed to the second anti-reflection layer 102 In the direction X of the direction, the nitrogen content of one of the first anti-reflection layer 101 and the second anti-reflection layer 102 tends to increase, and the nitrogen content of the other tends to decrease, and the first anti-reflection layer 101 and the content ratio of nitrogen element and silicon element in the second anti-reflection layer 102 ranges from 1.05 to 1.33, so it is beneficial to further ensure that the refractive index of the first anti-reflection layer 101 and the refractive index of the second anti-reflection layer 102 are opposite changing trend. It should be noted that the foregoing has described in detail about the "increasing trend", "the specific situation included in the increasing trend", "the decreasing trend" and "the specific situation included in the decreasing trend". The description about the increasing trend of nitrogen content and the description about the decreasing trend of nitrogen content will not be repeated here.

It should be noted that, in some embodiments, along the direction X, the content of oxygen and nitrogen in one of the first anti-reflection layer 101 and the second anti-reflection layer 102 both tend to increase, and the other Both the oxygen element content and the nitrogen element content of the first anti-reflection layer 101 and the nitrogen element content tend to decrease; in other embodiments, along the direction X, the nitrogen element content of only one of the first anti-reflection layer 101 and the second anti-reflection layer 102 may be Both showed an increasing trend, but the nitrogen content of the other showed a decreasing trend. In the foregoing two embodiments, along the direction X, the oxygen element content and/or nitrogen element content of one of the first anti-reflection layer 101 and the second anti-reflection layer 102 tends to increase, which will cause the oxygen element and the nitrogen element to increase. The content ratio of nitrogen element tends to increase, so that its refractive index tends to decrease; the oxygen element content and/or nitrogen element content of the other one of the first anti-reflection layer 101 and the second anti-reflection layer 102 decreases trend, the content ratio of oxygen element and nitrogen element will tend to decrease, so that the refractive index will tend to increase.

In the embodiment of the present disclosure, “along the direction X, the content of oxygen and nitrogen in the first anti-reflection layer 101 both show a decreasing trend, so that the content ratio of oxygen and nitrogen in the first anti-reflection layer 101 is shows a decreasing trend, so that the refractive index of the first anti-reflection layer 101 shows an increasing trend; the oxygen element content and nitrogen element content in the second anti-reflection layer 102 both show an increasing trend, so that the second anti-reflection layer 102 has an increasing trend. The content ratio of the oxygen element and the nitrogen element tends to increase, so that the refractive index of the second anti-reflection layer 102 has a decreasing trend” as an example. In practical applications, along the direction X, it can be: the first anti-reflection layer The content of oxygen element and the content of nitrogen element in the layer 101 both show an increasing trend, and the content of oxygen element and nitrogen element in the second anti-reflection layer 102 both show a decreasing trend.

In some embodiments, the content ratio of oxygen element and nitrogen element in the first anti-reflection layer 101 is not greater than 0.9, and the content ratio of oxygen element and nitrogen element in the second anti-reflection layer 102 is not greater than 0.9. It should be noted that, along the direction X, the oxygen element content in the first anti-reflection layer 101 tends to decrease, so there is no oxygen element in the partial area of the first anti-reflection layer 101, and only nitrogen and It is composed of silicon element, so there is a situation where the content ratio of oxygen element and nitrogen element in the first anti-reflection layer 101 is 0. Similarly, there is no oxygen element in the partial area of the second anti-reflection layer 102, and only nitrogen and nitrogen elements are present. It is composed of silicon element, so the content ratio of oxygen element and nitrogen element in the second anti-reflection layer 102 may be 0.

In some embodiments, the first silicon oxynitride material is a mixture of silicon oxide and silicon nitride, and the second silicon oxynitride material is a mixture of silicon oxide and silicon nitride. In the direction X of the direction of the anti-reflection layer 102, the content ratio of silicon oxide and silicon nitride in one of the first anti-reflection layer 101 and the second anti-reflection layer 102 tends to increase, and the content ratio of silicon oxide and nitride in the other The content ratio of silicon showed a decreasing trend.

In the embodiment of the present disclosure, “along the direction X, the content ratio of silicon oxide and silicon nitride in the first anti-reflection layer 101 tends to decrease, so that the content of oxygen element and nitrogen element in the first anti-reflection layer 101 is The ratio shows a decreasing trend, so that the refractive index of the first anti-reflection layer 101 shows an increasing trend; the content ratio of silicon oxide and silicon nitride in the second anti-reflection layer 102 shows an increasing trend, so that the second anti-reflection layer 102 has an increasing trend. The content ratio of oxygen element and nitrogen element in 102 shows an increasing trend, so that the refractive index of the second anti-reflection layer 102 shows a decreasing trend” as an example. In practical applications, along the direction X, it can be: the first The content ratio of silicon oxide and silicon nitride in the anti-reflection layer 101 has an increasing trend, and the content ratio of silicon oxide and silicon nitride in the second anti-reflection layer 102 has a decreasing trend.

In some embodiments, along the direction X, the reflectivity of the second anti-reflection layer 102 gradually increases as the content ratio of silicon oxide and silicon nitride in the second anti-reflection layer 102 increases, as shown in FIG. 6 . As shown, and along the direction parallel to the direction X and opposite to the direction X, the reflectivity of the first anti-reflection layer 101 gradually increases with the increase of the content ratio of silicon oxide and silicon nitride in the first anti-reflection layer 101 The increasing trend is also shown in Figure 6.

In some embodiments, the content ratio of silicon oxide and silicon nitride in the first anti-reflection layer 101 ranges from 0 to 1, and the content ratio of silicon oxide and silicon nitride in the second anti-reflection layer 102 ranges from 0 to 1. 1. It should be noted that, along the direction X, the content of silicon oxide in the first anti-reflection layer 101 tends to decrease, so there is no silicon oxide in the partial area of the first anti-reflection layer 101, only nitridation Therefore, the content ratio of silicon oxide and silicon nitride in the first anti-reflection layer 101 is 0. Similarly, there is no silicon oxide in the partial area of the second anti-reflection layer 102, and only silicon nitride is used. Therefore, there is a case where the content ratio of silicon oxide and silicon nitride in the second anti-reflection layer 102 is zero.

In some embodiments, continuing to refer to FIG. 1 , along the direction Y from the first anti-reflection layer 101 to the second anti-reflection layer 102 , the thicknesses of the first anti-reflection layer 101 and the second anti-reflection layer 102 are 30 nm˜50 nm.

To sum up, the first anti-reflection layer 101 and the second anti-reflection layer 102 cooperate with each other, and the first anti-reflection layer is designed along the direction X perpendicular to the direction of the first anti-reflection layer 101 to the second anti-reflection layer 102 The content of oxygen and/or nitrogen in 101 and the second anti-reflection layer 102 is gradually changed, so that the content ratio of oxygen and/or nitrogen in the first anti-reflection layer 101 and the second anti-reflection layer 102 is gradually changed, Then along the direction X perpendicular to the direction of the first anti-reflection layer 101 to the second anti-reflection layer 102, the refractive indices of the first anti-reflection layer 101 and the second anti-reflection layer 102 to light both gradually change, and the first The change trend of the refractive index of light to the anti-reflection layer 101 and the second anti-reflection layer 102 is different, which is beneficial to increase the probability of total reflection of light in the first anti-reflection layer 101 and the second anti-reflection layer 102, And reduce the probability that the light incident on the first anti-reflection layer 101 and the second anti-reflection layer 102 is refracted one or more times into the air, thereby greatly reducing the loss of light incident on the photovoltaic module and improving the photovoltaic module. Absorptivity of light incident on a photovoltaic module.

Another embodiment of the present application further provides a method for manufacturing a photovoltaic cell, which is used for manufacturing the photovoltaic cell provided in the above embodiment. The manufacturing method of the photovoltaic cell provided by another embodiment of the present application will be described in detail below with reference to the accompanying drawings. It should be noted that the parts corresponding to the foregoing embodiments will not be repeated here. 7 to 8 are schematic structural diagrams corresponding to each step of a method for manufacturing a photovoltaic cell according to another embodiment of the present application.

7 to 8 , the method for manufacturing a photovoltaic cell includes: providing a substrate 100; forming a first anti-reflection layer 101 on one side of the substrate 100; forming a second anti-reflection layer on a side of the first anti-reflection layer 101 away from the substrate 100 Layer 102, the first anti-reflection layer 101 includes a first silicon oxynitride material, and the second anti-reflection layer 102 includes a second silicon oxynitride material, along a direction perpendicular to the direction of the first anti-reflection layer 101 to the direction of the second anti-reflection layer 102 On X, the content ratio of oxygen and nitrogen in one of the first anti-reflection layer 101 and the second anti-reflection layer 102 tends to increase, and the content ratio of oxygen and nitrogen in the other tends to decrease. In this way, along the direction X, the refractive index of one of the first anti-reflection layer 101 and the second anti-reflection layer 102 tends to increase, and the refractive index of the other tends to decrease, and the first The difference between the refractive indices of the reflective layer 101 and the second anti-reflection layer 102 first shows a decreasing trend and then an increasing trend, which is beneficial to improve the light absorption rate of the photovoltaic cell.

In some embodiments, the method of manufacturing a photovoltaic cell may further include the following steps:

Referring to FIG. 1 and FIG. 7 , a chamber 103 is provided, and along the direction X perpendicular to the direction of the first anti-reflection layer 101 and the direction of the second anti-reflection layer 102 , the first air inlet 113 and The second air inlet 123 , and the air intake directions of the first air inlet 113 and the second air inlet 123 are opposite, and the substrate 100 is located between the first air inlet 113 and the second air inlet 123 .

It should be noted that the chamber 103 is further provided with a third gas inlet 133 for supplying the gas for forming the silicon nitride film layer. In some embodiments, the third gas inlet is used for simultaneously supplying the nitrogen source gas and the silicon source gas for forming the silicon nitride film layer. In other embodiments, the chamber may have a fourth gas inlet in addition to the third gas inlet, wherein one of the third gas inlet and the fourth gas inlet is used to provide the formation of the silicon nitride film The other one of the third gas inlet and the fourth gas inlet is used to supply the silicon source gas for forming the silicon nitride film layer.

Continuing to refer to FIG. 7 , the steps of forming the first anti-reflection layer 101 in the chamber 103 include: depositing a silicon nitride material on one side of the substrate 100 , and during the deposition process, opening the first gas inlet 113 and closing the second gas inlet 113 Air inlet 123; Referring to FIG. 8, the step of forming the second anti-reflection layer 102 in the chamber 103 includes: depositing a silicon nitride material on the side of the first anti-reflection layer 101 away from the substrate 100, and during the deposition process, The first air inlet 113 is closed and the second air inlet 123 is opened. Wherein, in the step of forming the first anti-reflection layer 101 and the step of forming the second anti-reflection layer 102, the gas provided by the first air inlet 113 and the second air inlet 123 is a gas containing at least oxygen element, and the first The three gas inlets 133 are always in an open state for supplying nitrogen source gas and silicon source gas for depositing the silicon nitride material.

Since the first air inlet 113 is in an open state and the second air inlet 123 is in a closed state when the first anti-reflection layer 101 is formed, during the process of forming the first anti-reflection layer 101 , the first anti-reflection layer 101 The farther away from the first air inlet 113, the lower the content of the gas containing at least the oxygen element, so it is beneficial to form the first anti-reflection layer 101 along the direction X with the oxygen element content gradually decreasing, so that the first anti-reflection layer 101 is formed. The refractive index of the layer 101 tends to increase in the direction X. Similarly, when the second anti-reflection layer 102 is formed, the first air inlet 113 is in a closed state and the second air inlet 123 is in an open state, then in the process of forming the second anti-reflection layer 102, the second anti-reflection The farther away from the second air inlet 123 in the layer 102, the less the content of the gas containing at least oxygen element is, so it is beneficial to form the second anti-reflection layer 102 along the direction X, the content of oxygen element gradually increases, so that the second anti-reflection layer 102 is formed. The refractive index of the anti-reflection layer 102 has a decreasing trend along the direction X. As shown in FIG.

In some embodiments, the gas containing at least elemental oxygen includes oxygen or nitrous oxide gas. If the gas containing at least oxygen element is nitrous oxide gas, in the process of forming the first anti-reflection layer 101 , a region of the first anti-reflection layer 101 that is farther away from the first air inlet 113 in the open state is formed. The smaller the content of nitrous oxide gas, the better the formation of the first anti-reflection layer 101 along the direction X, the content of oxygen and nitrogen elements are gradually reduced, so that the refractive index of the first anti-reflection layer 101 along the direction X is formed increasing trend. Similarly, in the process of forming the second anti-reflection layer 102, the content of nitrous oxide gas in the region of the second anti-reflection layer 102 that is farther away from the second air inlet 123 in the open state is less, which is beneficial to In the direction X, the second anti-reflection layer 102 is formed with the content of oxygen and nitrogen elements gradually increasing, so that the refractive index of the second anti-reflection layer 102 in the direction X tends to decrease.

In other embodiments, the gas provided by the first air inlet and the second air inlet may also be a gas containing nitrogen but not oxygen. By changing the different regions of the first anti-reflection layer and the second anti-reflection layer Different contents of nitrogen elements change the refractive index of different regions of the first anti-reflection layer and the second anti-reflection layer.

In some embodiments, the gases provided by the first air inlet 113 and the second air inlet 123 are the same, so it is beneficial to control the maximum refractive index of the first anti-reflection layer 101 and the refractive index of the second anti-reflection layer 102 The values are the same, and it is beneficial to control the minimum value of the refractive index of the first anti-reflection layer 101 and the refractive index of the second anti-reflection layer 102 to be the same.

In other embodiments, the gas provided by the first gas inlet may be different from the gas provided by the second gas inlet. For example, the gas provided by the first gas inlet may be oxygen, and the gas provided by the second gas inlet may be oxygen. for nitric oxide gas.

In some embodiments, the gas flow rate of the gas provided by the first gas inlet 113 is not higher than 150 mL/s, and the gas flow rate of the gas provided by the second gas inlet port 123 is not higher than 150 mL/s. In this way, it is beneficial to avoid providing too much gas containing at least oxygen element in the process of forming the first anti-reflection layer 101 and the second anti-reflection layer 102, and to avoid the gas in the first anti-reflection layer 101 and the second anti-reflection layer 102. The content of oxygen and/or nitrogen is too high, so that the content ratio of oxygen and nitrogen in the first anti-reflection layer 101 and the second anti-reflection layer 102 is too high to avoid the refractive index of the first anti-reflection layer 101 and the refractive index of the second anti-reflection layer 102 is too low. Since the refractive index of the first anti-reflection layer 101 and/or the refractive index of the second anti-reflection layer 102 is too low, it is not conducive to the total reflection of light in the first anti-reflection layer 101 and the second anti-reflection layer 102, and the light is easily transmitted from The first anti-reflection layer 101 and the second anti-reflection layer 102 are reflected into the air, causing unnecessary light loss. Therefore, in the process of forming the first anti-reflection layer 101 and the second anti-reflection layer 102, it is avoided to provide too much gas containing at least oxygen element, so as to avoid the refractive index of the first anti-reflection layer 101 and the second anti-reflection layer 102 If the difference is too large, it is beneficial to avoid unnecessary light loss, thereby improving the light absorption rate of the photovoltaic cell.

To sum up, in the formed photovoltaic cell, along the direction X, the content ratio of oxygen and nitrogen in one of the first anti-reflection layer 101 and the second anti-reflection layer 102 tends to increase, and the other The content ratio of oxygen element and nitrogen element tends to decrease, which is beneficial to make along the direction X, the refractive index of one of the first anti-reflection layer 101 and the second anti-reflection layer 102 tends to increase, and the other The refractive index of the first anti-reflection layer 101 and the second anti-reflection layer 102 show a decreasing trend first and then an increasing trend, which is beneficial to improve the absorption of light by the photovoltaic cell Rate.

Yet another embodiment of the present application also provides a photovoltaic assembly, which is used for converting received light energy into electrical energy. FIG. 9 is a schematic structural diagram of a photovoltaic module provided by another embodiment of the present application.

Referring to FIG. 9 , the photovoltaic assembly includes a battery string (not marked), an encapsulating film 140 and a cover plate 150 ; the battery string is formed by connecting a plurality of photovoltaic cells 130 , and the photovoltaic cells 130 may be any of the aforementioned photovoltaic cells, or may be the aforementioned photovoltaic cells In the photovoltaic cells prepared by any of the photovoltaic cell preparation methods described above, the adjacent photovoltaic cells 130 are electrically connected by conductive tapes (not shown). Can be spliced to each other; the encapsulating film 140 can be an ethylene-vinyl acetate copolymer (EVA) film, a polyethylene octene co-elastomer (POE) film or a polyethylene terephthalate (PET) film Such as organic encapsulation film, the encapsulation film 140 covers the surface of the battery string to seal; the cover plate 150 can be a transparent or translucent cover plate such as a glass cover plate or a plastic cover plate, the cover plate 150 is covered on the encapsulation film 140 away from the battery the surface of the string.

In some embodiments, a light trapping structure is provided on the cover plate 150 to increase the utilization rate of incident light, and the light trapping structure of different cover plates 150 may be different. Photovoltaic modules have high current collection capacity and low carrier recombination rate, which can achieve high photoelectric conversion efficiency; at the same time, the front of photovoltaic modules is dark blue or even black, which can be used in more scenes.

In some embodiments, the encapsulation film 140 and the cover plate 150 are only located on the front surface of the photovoltaic cell 130 to avoid further blocking and weakening of weak light by the encapsulation film 140 and the cover plate 150 located on the rear surface; The module can also be encapsulated by the sides, that is, the side of the photovoltaic module is completely covered by the encapsulation film 140, so as to prevent the lamination offset of the photovoltaic module during the lamination process, and to prevent the external environment from passing through the photovoltaic module. side affects the performance of photovoltaic cells, such as water vapor intrusion.

Those of ordinary skill in the art can understand that the above-mentioned embodiments are specific examples for realizing the present application, and in practical applications, various changes can be made in form and details without departing from the embodiments of the present application. spirit and scope. Any person skilled in the art can make respective changes and modifications without departing from the spirit and scope of the embodiments of the present application. Therefore, the protection scope of the embodiments of the present application should be subject to the scope defined by the claims.

Claims (16)

1. A photovoltaic cell, characterized in that, comprising: base; a first anti-reflection layer, located on one side of the substrate; A second anti-reflection layer, located on the side of the first anti-reflection layer away from the substrate, the first anti-reflection layer includes a first silicon oxynitride material, and the second anti-reflection layer includes a second silicon oxynitride material material, along the direction perpendicular to the direction of the first anti-reflection layer pointing to the second anti-reflection layer, the oxygen and nitrogen elements of one of the first anti-reflection layer and the second anti-reflection layer are The content ratio showed an increasing trend, and the content ratio of the other oxygen element and nitrogen element showed a decreasing trend. 2. The photovoltaic cell according to claim 1, wherein the content ratio of oxygen element and nitrogen element in the first anti-reflection layer is not greater than 0.9, and the content ratio of oxygen element and nitrogen element in the second anti-reflection layer is not greater than 0.9. The content ratio is not more than 0.9. 3. The photovoltaic cell of claim 1, wherein the first silicon oxynitride material is a mixture of silicon oxide and silicon nitride, and the second silicon oxynitride material is a mixture of silicon oxide and silicon nitride A mixture of silicon oxide and silicon nitride of one of the first anti-reflection layer and the second anti-reflection layer in a direction perpendicular to the direction of the first anti-reflection layer to the second anti-reflection layer The content ratio of silicon oxide and silicon nitride shows a decreasing trend. 4 . The photovoltaic cell according to claim 3 , wherein the content ratio of silicon oxide and silicon nitride in the first anti-reflection layer varies from 0 to 1, and the silicon oxide in the second anti-reflection layer The content ratio of silicon nitride and silicon nitride varies from 0 to 1. 5. The photovoltaic cell of claim 1, wherein in a direction perpendicular to the direction of the first anti-reflection layer pointing to the second anti-reflection layer, the first anti-reflection layer and the second anti-reflection layer The oxygen element content of one of the two anti-reflection layers shows an increasing trend, and the oxygen element content of the other shows a decreasing trend, and the oxygen and silicon elements in the first anti-reflection layer and the second anti-reflection layer The content ratio is not more than 0.5. 6. The photovoltaic cell of claim 5, wherein in a direction perpendicular to the direction of the first anti-reflection layer pointing to the second anti-reflection layer, the first anti-reflection layer and the second anti-reflection layer The nitrogen element content of one of the two anti-reflection layers shows an increasing trend, and the nitrogen element content of the other one shows a decreasing trend, and the nitrogen and silicon elements in the first anti-reflection layer and the second anti-reflection layer The variation range of the content ratio is 1.05~1.33. 7 . The photovoltaic cell according to claim 1 , wherein along the direction from the first anti-reflection layer to the second anti-reflection layer, the thickness of the first anti-reflection layer is 30 nm to 50 nm, 8 . The thickness of the second anti-reflection layer is 30nm˜50nm. 8 . The photovoltaic cell according to claim 1 , wherein in a direction perpendicular to the direction of the first anti-reflection layer pointing to the second anti-reflection layer, the first anti-reflection layer The refractive index of one of the layer and the second anti-reflection layer tends to increase, and the refractive index of the other tends to decrease, and the refraction of the first anti-reflection layer and the second anti-reflection layer The difference of the ratios firstly decreased and then increased. 9 . The photovoltaic cell according to claim 8 , wherein the maximum value of the refractive index of the first anti-reflection layer and the refractive index of the second anti-reflection layer is 1.9˜2.1, and the first The minimum value of the refractive index of the reflection layer and the refractive index of the second anti-reflection layer is 1.4-1.6. 10 . The photovoltaic cell of claim 8 , wherein the highest value of the refractive index of the first anti-reflection layer is the same as the highest value of the refractive index of the second anti-reflection layer, and the first anti-reflection layer The lowest value of the refractive index of is the same as the lowest value of the refractive index of the second anti-reflection layer. 11. A method of manufacturing a photovoltaic cell, comprising: provide a base; forming a first anti-reflection layer on one side of the substrate; A second anti-reflection layer is formed on the side of the first anti-reflection layer away from the substrate, the first anti-reflection layer includes a first silicon oxynitride material, and the second anti-reflection layer includes a second silicon oxynitride material material, along the direction perpendicular to the direction of the first anti-reflection layer pointing to the second anti-reflection layer, the oxygen and nitrogen elements of one of the first anti-reflection layer and the second anti-reflection layer are The content ratio showed an increasing trend, and the content ratio of the other oxygen element and nitrogen element showed a decreasing trend. 12. The manufacturing method of claim 11, further comprising: A chamber is provided, and along a direction perpendicular to the direction of the first anti-reflection layer pointing to the second anti-reflection layer, a first air inlet and a second air inlet are sequentially arranged on the chamber, and the The air intake directions of the first air inlet and the second air inlet are opposite, and the base is located between the first air inlet and the second air inlet; The step of forming the first anti-reflection layer in the chamber includes depositing a silicon nitride material on one side of the substrate, and during the deposition, opening the first gas inlet and closing the second gas inlet air intake; The step of forming the second anti-reflection layer in the chamber includes: depositing a silicon nitride material on a side of the first anti-reflection layer away from the substrate, and during the deposition process, turning off the first anti-reflection layer. air inlet and open the second air inlet; In the step of forming the first anti-reflection layer and the step of forming the second anti-reflection layer, the gas provided by the first gas inlet and the second gas inlet is a gas containing at least oxygen element. 13. The manufacturing method according to claim 12, wherein the gas containing at least oxygen element includes oxygen gas or nitrous oxide. 14. The manufacturing method of claim 12, wherein the first gas inlet and the second gas inlet provide the same gas. 15. The manufacturing method according to claim 12, wherein the gas flow rate of the gas provided by the first air inlet is not higher than 150 mL/s, and the gas flow rate of the gas provided by the second air inlet is not higher than 150 mL/s. higher than 150mL/s. 16. A photovoltaic module, comprising: a string of cells formed by connecting photovoltaic cells as claimed in any one of claims 1 to 10, or by connecting photovoltaic cells manufactured by a manufacturing method as claimed in any one of claims 11 to 15; an encapsulation film for covering the surface of the battery string; a cover plate for covering the surface of the packaging adhesive film facing away from the battery string.

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