HBC battery, battery pack and photovoltaic system

Abstract

The utility model is applicable to the field of photovoltaic technology, and provides an HBC battery, a battery pack and a photovoltaic system, the HBC battery comprises silicon: a substrate, the silicon substrate is provided with a backlight surface and a light facing surface which are oppositely arranged, the backlight surface of the silicon substrate is provided with a first area and a second area, the first area and the second area are alternately arranged, and the first area and the second area are not overlapped; an amorphous silicon layer is arranged in the first region, a polycrystalline silicon layer is arranged in the second region, the amorphous silicon layer and the polycrystalline silicon layer are in a special shape, and the extinction coefficient of the amorphous silicon layer is larger than that of the polycrystalline silicon layer. According to the manufacturing method, the polycrystalline silicon layer has relatively high compactness, so that the polycrystalline silicon layer has relatively high electrode slurry etching resistance, a manufactured electrode is prevented from penetrating through the polycrystalline silicon layer, the matching between the polycrystalline silicon layer and electrode slurry is improved, and the polycrystalline silicon layer is ensured to have a relatively high field passivation effect; the carrier recombination rate on one side of the backlight surface is reduced, and the working performance of the solar cell is improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to photovoltaic technology field especially relates to a kind of HBC battery, battery pack and photovoltaic system. BACKGROUND

[0002] In the existing HBC (heterojunction with back contact) battery, compared with BC (back contact) battery, significant progress has been made, but there are still some technical problems, which limit its further improvement of photoelectric conversion efficiency and reduce manufacturing cost.

[0003] HBC battery relies on heterojunction structure in design, which improves photoelectric conversion efficiency, and improper heterojunction processing can easily lead to the recombination of generated carriers before reaching the electrode, reducing the current that can be collected, resulting in increased recombination rate of carriers. And the lack of material density leads to poor etching resistance, especially in the electrode manufacturing process, the electrode slurry used may cause damage or penetration to the material layer, affecting the matching between the electrode and the silicon layer, and thus affecting the overall performance and stability of the battery. SUMMARY

[0004] The utility model provides a kind of HBC battery, to solve the problem of the recombination rate of carrier increase and the stability of insufficient in the existing HBC battery.

[0005] The utility model is realized as follows: a kind of HBC battery, comprising:

[0006] Silicon substrate, the silicon substrate has oppositely arranged back light surface and light surface, first area and second area are arranged on the back light surface of the silicon substrate, the first area and the second area are alternately arranged, and the first area and the second area do not overlap.

[0007] Amorphous silicon layer is included in the first area, and polycrystalline silicon layer is included in the second area, the amorphous silicon layer and the polycrystalline silicon layer are different types, and the extinction coefficient of the amorphous silicon layer is greater than the extinction coefficient of the polycrystalline silicon layer.

[0008] Optionally, the ratio of the extinction coefficient of the amorphous silicon layer to the extinction coefficient of the polycrystalline silicon layer is greater than 1.3 and less than 11.

[0009] Optionally, the difference between the extinction coefficient of the amorphous silicon layer and the extinction coefficient of the polycrystalline silicon layer is greater than 0.01 and less than 0.08.

[0010] Optionally, it further includes isolation region, and the isolation region is placed between the first area and the second area.

[0011] Optionally, the thickness of the amorphous silicon layer is greater than 13nm and less than 17nm.

[0012] Optionally, the thickness of the polysilicon layer is greater than 280nm and less than 300nm.

[0013] Optionally, the refractive index of the amorphous silicon layer is greater than the refractive index of the polysilicon layer.

[0014] Optionally, the ratio of the refractive index of the amorphous silicon layer to the refractive index of the polysilicon layer is greater than 1 and less than 1.2.

[0015] Optionally, the difference of the refractive index of the amorphous silicon layer to the refractive index of the polysilicon layer is greater than 0.01 and less than 0.5.

[0016] Optionally, the amorphous silicon layer is a P-type amorphous silicon layer and the polysilicon layer is an N-type polysilicon layer.

[0017] The utility model also provides a battery pack, including above -mentioned HBC battery.

[0018] The utility model also provides a photovoltaic system, including above -mentioned battery pack.

[0019] The utility model discloses reached the beneficial effects, because the first area and the second area of not overlapping alternately are arranged on the back light surface of silicon base, the extinction coefficient of the amorphous silicon layer arranged in the first area is greater than the extinction coefficient of the polysilicon layer arranged in the second area, make the polysilicon layer have relatively higher compactness, and then make the polysilicon layer have relatively higher electrode slurry etching ability, prevent the electrode of manufacture to penetrate the polysilicon layer, improve the matching between the polysilicon layer and electrode slurry, and ensure that the polysilicon layer has higher field passivation effect, reduce the carrier recombination rate of back light surface side, improve the working performance of solar cell. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is the schematic diagram of solar cell structure that the utility model provides.

[0021] Mark explanation:

[0022] 100, HBC battery; 110, first area; 111, amorphous silicon layer; 120, second area; 121, polysilicon layer; 130, isolation area; 140, silicon base. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical scheme and advantages of the utility model more clearly, the following will be further described in detail by combining with the drawings and examples. The examples of the examples are shown in the drawings, wherein the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The examples described below by referring to the drawings are exemplary and are only used to explain the utility model, and cannot be understood as limiting the utility model. In addition, it should be understood that the specific examples described herein are only used to explain the utility model, and are not used to limit the utility model.

[0024] In the description of the utility model, it should be understood that the terms "length", "width", "upper", "lower", "left", "right", "horizontal", "top", "bottom" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore, it cannot be understood as limiting the utility model.

[0025] In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include one or more of the features. In the description of the utility model, the meaning of "multiple" is two or more than two, unless otherwise specifically limited.

[0026] In the description of the utility model, it should be noted that unless otherwise specifically specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, it can be the communication or interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0027] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can include the first and second features directly contacting, or the first and second features not directly contacting but contacting through another feature between them.

[0028] The disclosure below provides many different embodiments or examples for implementing different structures of the present application. In order to simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeatedly refer to numbers and / or letters in different examples, and such repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the present application provides examples of various specific processes and materials, but those skilled in the art can realize the application of other processes and / or the use of other materials.

[0029] The present application alternately sets the first region and the second region which do not overlap on the back light surface of the silicon substrate, sets the extinction coefficient of the amorphous silicon layer in the first region to be greater than the extinction coefficient of the polycrystalline silicon layer set in the second region, so that the polycrystalline silicon layer has relatively high density, and then the polycrystalline silicon layer has relatively high resistance to electrode paste etching, prevents the electrode from penetrating the polycrystalline silicon layer, improves the matching between the polycrystalline silicon layer and the electrode paste, and ensures that the polycrystalline silicon layer has high field passivation effect, reduces the carrier recombination rate on the back light surface side, and improves the working performance of the solar cell.

[0030] Example One

[0031] As shown in Figure 1 The present embodiment provides an HBC battery 100, comprising:

[0032] The silicon substrate 140 has a back light surface and a light surface arranged oppositely, the first region 110 and the second region 120 are arranged on the back light surface of the silicon substrate 140, the first region 110 and the second region 120 are alternately arranged, and the first region 110 and the second region 120 do not overlap;

[0033] The amorphous silicon layer 111 is included in the first region 110, and the polysilicon layer 121 is included in the second region 120. The amorphous silicon layer 111 and the polysilicon layer 121 are different types. The extinction coefficient of the amorphous silicon layer 111 is greater than the extinction coefficient of the polysilicon layer 121.

[0034] The HBC solar cell 100 is a solar cell with a heterojunction structure and a back contact design. It combines the advantages of different materials to improve the photoelectric conversion efficiency. The heterojunction is formed on the back of the cell by different types of silicon materials (usually amorphous silicon and polysilicon), which can improve the performance of the cell.

[0035] The silicon substrate 140 has two main faces, the light-facing face and the back-facing face. The light-facing face is directly facing the sunlight, while the back-facing face is the other side. The two faces are oppositely arranged.

[0036] Two different regions, the first region 110 and the second region 120, are arranged on the back-facing face of the silicon substrate 140. The two regions are alternately arranged and do not overlap with each other. The first region 110 and the second region 120 can be adjacent to each other, or other regions can be arranged between the first region 110 and the second region 120.

[0037] The amorphous silicon layer 111 is included in the first region 110. The atomic arrangement of the amorphous silicon layer 111 is disordered and has no long-range order. The polysilicon layer 121 is included in the second region 120. The polysilicon is composed of a plurality of small silicon crystals, which aggregate to form larger structures, but there are grain boundaries between the grains. The amorphous silicon layer 111 and the polysilicon layer 121 are different types. When the amorphous silicon layer 111 is P-type, the polysilicon layer 121 is N-type, and when the amorphous silicon layer 111 is N-type, the polysilicon layer 121 is P-type. The N-type and P-type form a PN junction.

[0038] The higher the extinction coefficient, the stronger the light absorption ability, and the lower the extinction coefficient, the weaker the light absorption ability. The extinction coefficient of the amorphous silicon layer 111 is greater than the extinction coefficient of the polysilicon layer 121, so the light absorption ability of the amorphous silicon layer 111 is greater than the light absorption ability of the polysilicon layer 121.

[0039] At the same time, the smaller the extinction coefficient means that the material structure is more dense and uniform. The defects and voids inside the dense polysilicon layer 121 are fewer, which leads to the enhancement of its physical stability and mechanical strength. On the one hand, the polysilicon layer 121 has high density, and the structure is more stable and uniform, which can better resist the etching of the electrode slurry in the manufacturing process. This can ensure that the polysilicon layer 121 maintains its integrity during the electrode printing and sintering process, reducing the loss of electrical performance caused by etching. On the other hand, the high density of the polysilicon layer 121 can effectively passivate the surface, reduce the trap states on the surface and in the bulk, and thus reduce the recombination rate of electrons and holes on the back surface side.

[0040] In this embodiment, the first region 110 and the second region 120 are alternately arranged on the back surface of the silicon substrate 140 without overlapping, the extinction coefficient of the amorphous silicon layer 111 arranged in the first region 110 is greater than the extinction coefficient of the polysilicon layer 121 arranged in the second region 120, so that the polysilicon layer 121 has relatively high density, and thus the polysilicon layer 121 has relatively high resistance to electrode slurry etching, prevents the manufactured electrode from penetrating the polysilicon layer 121, improves the matching between the polysilicon layer 121 and the electrode slurry, and ensures that the polysilicon layer 121 has high field passivation effect, reduces the carrier recombination rate on the back surface side, and improves the working performance of the solar cell.

[0041] Example Two

[0042] On the basis of Embodiment One, the ratio of the extinction coefficient of the amorphous silicon layer 111 to the extinction coefficient of the polysilicon layer 121 is greater than 1.3 and less than 11.

[0043] By selecting the amorphous silicon layer 111 and the polysilicon layer 121 with an extinction coefficient ratio between 1.3 and 11, efficient light absorption and optimized light management are achieved in the first region 110 and the second region 120. This is crucial for enhancing light capture and the generation of electron-hole pairs. The appropriate extinction coefficient ratio ensures good matching between the polysilicon layer 121 and the electrode slurry, reduces electrical contact resistance, enhances electrode adhesion, and makes the polysilicon layer 121 have higher resistance to electrode slurry etching, ensuring the stability of the layer structure during printing and sintering. By precisely controlling the extinction coefficient ratio of the amorphous silicon layer 111 and the polysilicon layer 121, the surface is effectively passivated, the defects caused by disordered structures are reduced, and thus the carrier recombination rate is reduced. The field passivation effect is enhanced, which helps to improve the open-circuit voltage and fill factor of the cell, and ultimately improves the photoelectric conversion efficiency.

[0044] The extinction coefficient is reasonably selected to achieve the best balance between light absorption and electrical conductivity of the amorphous silicon layer 111 and the polysilicon layer 121. This improves the photoelectric conversion efficiency of the solar cell, prolongs the service life of the cell, and improves the output power and use stability.

[0045] Example Three

[0046] On the basis of embodiment one, the difference between the extinction coefficient of the amorphous silicon layer 111 and the extinction coefficient of the poly-silicon layer 121 is greater than 0.01 and less than 0.08.

[0047] Specifically, amorphous silicon has a higher extinction coefficient, more effectively absorbing high-energy photons, while poly-silicon has a lower extinction coefficient, but within this small difference range, it can more evenly absorb photons, thereby improving the light absorption efficiency of the entire cell. Since the difference is between 0.01 and 0.08, the reflection and scattering of photons at the interface of the two materials is low, plus the appropriate anti-reflection layer design, which can further reduce light loss and optimize light capture.

[0048] Example Four

[0049] On the basis of embodiment one, it further includes an isolation region 130, which is placed between the first region 110 and the second region 120.

[0050] The isolation region 130 can effectively separate the first region 110 and the second region 120, preventing the mixing and recombination of charge carriers. In this way, charges can be more effectively separated and transmitted within their respective regions. The isolation region 130 reduces the opportunity for photo-generated carriers to migrate across regions, reducing the probability of carrier recombination, thereby improving the photoelectric conversion efficiency of the solar cell.

[0051] The isolation region 130 also helps to reduce the interface defects between the amorphous silicon layer 111 and the poly-silicon layer 121. These defects are usually the main source of carrier recombination, so by setting the isolation region 130, the passivation effect of the interface can be improved, thereby improving the performance of the cell. The presence of the isolation region 130 makes the interface between the amorphous silicon layer 111 and the poly-silicon layer 121 more stable, reducing the expansion of defects caused by repeated stress and thermal cycling at the interface.

[0052] Example Five

[0053] On the basis of embodiment one, the thickness of the amorphous silicon layer 111 is greater than 13 nm and less than 17 nm.

[0054] The amorphous silicon layer 111 has a thickness in the range of 13 nm to 17 nm, which is beneficial for more efficient charge separation. An amorphous silicon layer 111 that is too thick may increase the recombination rate of charges, while a layer that is too thin may not be sufficient to effectively separate photo-generated carriers. A reasonable thickness of the amorphous silicon layer 111 can provide a better charge transport path, reducing energy loss during the charge transport process, thereby improving the photoelectric conversion efficiency of the cell.

[0055] Example Six

[0056] In the embodiment one, the thickness of the polysilicon layer 121 is greater than 280 nm and less than 300 nm.

[0057] The thickness of the polysilicon layer 121 in the range of 280 nm to 300 nm helps to efficiently separate photo-generated charges. This thickness range avoids both the recombination of charges inside the material and provides sufficient volume to support efficient charge transport. The polysilicon layer 121 with thickness in this range can reduce the resistance and increase the carrier transport speed, thus improving the fill factor and overall efficiency of the cell.

[0058] Example Seven

[0059] In the embodiment one, the refractive index of the amorphous silicon layer 111 is greater than the refractive index of the polysilicon layer 121.

[0060] Since the refractive index of the amorphous silicon layer 111 is greater than the polysilicon layer 121, when light enters the amorphous silicon layer 111, the propagation path of the light will be refracted, so that most of the light can continue to pass into the polysilicon layer 121, thereby reducing the parasitic absorption in the amorphous silicon layer 111. At the same time, the higher refractive index makes the amorphous silicon layer 111 have higher light penetration ability, which means that more light can penetrate the amorphous silicon layer 111 and reach the polysilicon layer 121 with higher absorption capacity, improving the overall light absorption efficiency.

[0061] Example Eight

[0062] In the embodiment seven, the ratio of the refractive index of the amorphous silicon layer 111 to the refractive index of the polysilicon layer 121 is greater than 1 and less than 1.2.

[0063] By precisely controlling the refractive index ratio of the amorphous silicon layer 111 and the polysilicon layer 121 between 1 and 1.2, the propagation path of light can be precisely regulated to ensure effective transmission and absorption of light, maximizing optical utilization. This ratio range helps to achieve micro-optical matching between layers, reducing light reflection loss at the interface, thereby improving the light absorption efficiency of the cell.

[0064] Example Nine

[0065] In the embodiment one, the difference between the refractive index of the amorphous silicon layer 111 and the refractive index of the polysilicon layer 121 is greater than 0.01 and less than 0.5.

[0066] The refractive index difference between the amorphous silicon layer 111 and the polysilicon layer 121 is limited to 0.01 to 0.5, so that the light reflection between the two layers of materials is minimized, thereby improving the light absorption efficiency. This refractive index difference range helps to achieve multiple reflections and effective transmission of light inside the cell, thereby increasing the optical utilization.

[0067] Example Ten

[0068] On the basis of the first embodiment, the amorphous silicon layer 111 is a P-type amorphous silicon layer 111, and the polysilicon layer 121 is an N-type polysilicon layer 121.

[0069] Amorphous silicon has a high density of defect states, and these defects can capture electrons, resulting in low electron mobility. However, holes move relatively smoothly in amorphous silicon, so amorphous silicon is more suitable as a P-type material. Amorphous silicon as a P-type material can also effectively passivate the interface with the polysilicon or crystalline silicon substrate 140, reducing carrier recombination caused by interface defect states, thereby improving interface quality. Moreover, amorphous silicon as a P-type layer has good long-term stability, mature process, and relatively easy process parameters to control, meeting the requirements of large-scale industrial production.

[0070] The number of free electrons in N-type polysilicon is large, and the electron mobility is high, which can effectively improve the conductivity of the device and reduce resistance loss. The crystalline structure of polysilicon is better than that of amorphous silicon, and has a lower defect state density, which makes polysilicon a better N-type material for conducting electrons.

[0071] Setting the amorphous silicon layer 111 as P-type and the polysilicon layer 121 as N-type makes full use of the advantages of each material, optimizes the transmission and separation efficiency of carriers, and improves the photoelectric conversion efficiency.

[0072] Example Eleven

[0073] The present embodiment provides a battery pack comprising the HBC cell 100 of the above-mentioned embodiments.

[0074] The battery pack of the present embodiment has the same advantages as the HBC cell 100 described above, and will not be repeated here.

[0075] Example Twelve

[0076] The present embodiment provides a photovoltaic system comprising the battery pack of the above-mentioned embodiments.

[0077] The photovoltaic system of the present embodiment has the same advantages as the battery pack described above, and will not be repeated here.

[0078] The above merely describes the preferred embodiments of the present application, and is not intended to limit the present application, and any modification, equivalent replacement, and improvement within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An HBC battery characterized by, The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery.

2. A HBC battery as claimed in claim 1, characterized in that The application relates to a HBC battery.

3. A HBC battery as in claim 1, wherein, The application relates to a HBC battery.

4. A HBC battery as in claim 1, wherein, The application relates to a HBC battery.

5. A HBC battery as in claim 1, wherein, The application relates to a HBC battery.

6. A HBC battery as in claim 1, wherein, The application relates to a HBC battery.

7. A HBC battery as in claim 1, wherein, The application relates to a HBC battery.

8. A HBC battery as in claim 1, wherein, The application relates to a HBC battery.

9. A HBC battery as in claim 1, wherein, The application relates to a HBC battery.

10. A battery pack characterized by comprising: The application relates to a HBC battery.

11. A photovoltaic system characterized by, The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to a HBC battery. The application relates to

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