Solar cell, cell slice, cell assembly and photovoltaic system
By designing a tunneling passivation layer with decreasing thickness and a porous structure in solar cells, the problem of stress damage during the fabrication of the tunneling passivation layer is solved, improving carrier transport efficiency and photoelectric conversion efficiency, making it suitable for industrial production.
Patent Information
- Application Number
- CN202422584752.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-24
- Publication Date
- 2025-11-07
- Estimated Expiration
- 2034-10-24
AI Technical Summary
In the fabrication process of existing solar cells, the tunneling passivation layer is easily damaged by stress, which leads to a decrease in carrier transport efficiency and affects photoelectric conversion efficiency.
The thickness of the tunneling passivation layer is designed to decrease from the periphery of the second end face towards the center, and pores are set in the tunneling passivation layer. The pore density increases as the thickness decreases, so as to improve the resistance to stress damage and the carrier transport efficiency.
It effectively prevents stress damage from hindering carrier transport, improves carrier transport efficiency and photoelectric conversion efficiency, and is suitable for industrial production.
Smart Images
Figure CN223528430U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to solar cell technical field especially relates to a solar cell piece, battery piece, battery assembly and photovoltaic system. BACKGROUND
[0002] In some existing solar cells, a tunneling passivation layer with uniform thickness is introduced to maintain good chemical passivation effect and realize selective carrier transport. The existing solar cells mostly utilize the tunneling characteristics of the tunneling passivation layer to promote the transport of carriers. However, the tunneling characteristics are extremely sensitive to the thickness, and the tunneling passivation layer needs to be extremely thin to better exert the tunneling characteristics. Therefore, the thickness of the tunneling passivation layer on the current solar cells is extremely thin.
[0003] However, the inventor finds that, in the actual preparation process, after the deposition of the ultra-thin tunneling passivation layer, the solar cell still needs to undergo steps such as laser grooving, heat processing, cell cutting, and lamination. These steps are prone to cause stress damage to the tunneling passivation layer. The stress damage will hinder the transport of carriers, reduce the transport efficiency of carriers, and affect the photoelectric conversion efficiency of the solar cell. SUMMARY
[0004] The utility model aims at the existing technical situation and provides a solar cell piece, battery piece, battery assembly, and photovoltaic system.
[0005] The tunneling passivation layer of the utility model can balance the better anti-stress loss capability and the higher carrier transport efficiency, avoid the hindrance of stress damage to the transport of carriers in the preparation process, and effectively improve the battery conversion efficiency.
[0006] To achieve the above-mentioned purpose, the utility model adopts the following technical solutions:
[0007] Firstly, the utility model provides a solar cell piece, which comprises:
[0008] A silicon substrate has opposite first and second end faces,
[0009] A doped layer is arranged on the second end face,
[0010] A tunneling passivation layer is arranged between the second end face and the doped layer, and the thickness of the tunneling passivation layer decreases from the periphery of the second end face to the center.
[0011] In some embodiments, the tunneling passivation layer has a maximum thickness end with the maximum thickness and a minimum thickness end with the minimum thickness, and the ratio a of the maximum thickness end to the minimum thickness end is 1 < a ≤ 2.7.
[0012] In some embodiments, the tunneling passivation layer has a maximum thickness end with a maximum thickness and a minimum thickness end with a minimum thickness, and a ratio a of the maximum thickness end to the minimum thickness end is 1.3≤a≤2.7.
[0013] In some embodiments, the maximum thickness end has a thickness of 1.4nm-2.4nm, and the minimum thickness end has a thickness of 0.8nm-1.8nm.
[0014] In some embodiments, the tunneling passivation layer has a thickness satisfying the following formula:
[0015]
[0016] In the formula, H(x, y) is the thickness of the tunneling passivation layer at a point (x, y) on the second end surface, x and y are horizontal and vertical distances from the center of the second end surface to the point (x, y), 0 c x<0.5a and 0 7 y<0.5b, H0 is the thickness of the edge of the tunneling passivation layer, H -2 is the thickness of the tunneling passivation layer at the center of the second end surface, k is a constant coefficient and k>0, a is the length of the tunneling passivation layer, b is the width of the tunneling passivation layer, β is an adjustment coefficient, and ρ is a deviation coefficient.
[0017] In some embodiments, the tunneling passivation layer is provided with holes with openings facing the doped layer, and the density of the holes increases with the thickness of the tunneling passivation layer decreasing.
[0018] In some embodiments, the doped layer is a first polarity doped layer, and the first polarity doped layer has the same polarity as the silicon substrate.
[0019] In some embodiments, the doped layer includes N-type doped regions and P-type doped regions arranged alternately and spaced apart,
[0020] The tunneling passivation layer includes an N-region passivation layer corresponding to being arranged inside the N-type doped regions and a P-region passivation layer corresponding to being arranged inside the P-type doped regions, and the N-region passivation layer is provided with N-region holes with openings facing the doped layer, and the P-region passivation layer is provided with P-region holes with openings facing the doped layer.
[0021] In some embodiments, the density of the N-region holes and / or the P-region holes increases with the thickness of the tunneling passivation layer decreasing.
[0022] In some embodiments, the density of the P-region holes is greater than the density of the N-region holes.
[0023] In some embodiments, the density of the P-region holes is 1×10 7 cm -2 -1×1010 cm -2 .
[0024] In some embodiments, the density of the N region holes is 1x10 6 cm -2 ~1x10 9 cm -2 .
[0025] Secondly, the utility model provides a kind of battery piece, is made by the above-mentioned solar cell piece segmentation.
[0026] Secondly, the utility model provides a kind of battery assembly, comprising the above-mentioned solar cell piece.
[0027] Further, the utility model provides a kind of photovoltaic system, comprising the above-mentioned battery assembly.
[0028] The beneficial effects of the utility model are as follows:
[0029] 1) due to laser grooving, hot working, cell cutting, laminating and other steps, these steps are prone to cause stress damage to the tunneling passivation layer, and the closer to the edge position of the back light surface, the greater the stress damage, in the utility model, the thickness of the tunneling passivation layer decreases from the four peripheral edges of the second end face to the middle direction, so that the tunneling passivation layer has higher ability to withstand and resist stress loss at the position closer to the four peripheral edges of the second end face, prevents stress damage from hindering the transport of carriers, and compared with simply increasing the thickness of the entire material layer, the thickness of the tunneling passivation layer in the utility model is thinner at the position closer to the middle of the second end face, which ensures that the tunneling passivation layer not only prevents stress damage from hindering the transport of carriers, but also has higher carrier transport efficiency as a whole, thereby effectively improving the battery conversion efficiency.
[0030] 2) in the utility model, holes are arranged on the tunneling passivation layer, which can serve as the main transport channel for carriers, so that part of the carriers can directly pass through the tunneling passivation layer through the tunneling characteristic, and part of the carriers are first captured by the holes and then jump to the energy level on the other side through the tunneling process or thermal excitation, which cooperates with the tunneling characteristic of the tunneling passivation layer through the hole transport channel to effectively improve the transport efficiency of the carriers and reduce the sensitivity and dependence of the carrier transport on the ultra-thin thickness of the tunneling passivation layer, so that the thickness of the tunneling passivation layer can be relatively thicker, thereby obtaining better interface passivation effect, and further obtaining a tunneling passivation layer with better carrier transport efficiency and passivation effect, which effectively improves the photoelectric conversion efficiency of the battery.
[0031] Meanwhile, the place where the tunneling passivation layer with a larger thickness is located at the periphery of the second end face, that is, the place where stress damage is most likely to occur, and the density of the holes through the tunneling passivation layer decreases with the thickness of the tunneling passivation layer, so that relatively fewer holes are arranged at the place where stress damage is most likely to occur, so as to avoid the influence of too many holes on the ability of resisting stress damage, and as many holes as possible are arranged at the place where stress influence is small, so that the tunneling passivation layer has more transmission channels on the basis of effectively preventing stress damage from hindering the transportation of carriers, and the overall carrier transmission efficiency is ensured, so that the battery conversion efficiency can be further improved. BRIEF DESCRIPTION OF DRAWINGS
[0032] Figure 1 It is a structure schematic view of a tunneling passivation layer of a solar cell piece of the utility model.
[0033] Figure 2 It is a scanning electron microscope picture of the tunneling passivation layer of the utility model (the length scale in the figure is 1 μm).
[0034] Figure 3 It is a structure schematic view of one embodiment of a solar cell piece of the utility model.
[0035] Figure 4 It is a structure schematic view of another embodiment of a solar cell piece of the utility model.
[0036] Figure 5 It is Figure 4 A part enlarged view of A part of the utility model. DETAILED DESCRIPTION
[0037] In order to make the purpose, technical scheme and advantages of the utility model more clear and explicit, the utility model is further described in detail below by combining with the drawings and examples. The examples of the examples are shown in the drawings, wherein the same or similar reference signs 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 do not limit the utility model.
[0038] In this text, the phrase "embodiment" or "embodiment" means that the specific features, components or characteristics described in combination with the embodiment or embodiment can be contained in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily mean the same embodiment, nor is it an independent or alternative embodiment that is not mutually exclusive with other embodiments. The skilled person in the art explicitly and implicitly understands that the embodiments described herein can be combined with other embodiments.
[0039] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can include direct contact between the first and second features, or indirect contact between the first and second features through another feature therebetween. Moreover, the first feature "on", "above" and "on top of" the second feature includes the first feature directly above and obliquely above the second feature, or only indicates that the first feature is higher in horizontal height than the second feature. The first feature "under", "below" and "underneath" the second feature includes the first feature directly below and obliquely below the second feature, or only indicates that the first feature is lower in horizontal height than the second feature.
[0040] First, referring to Figure 1 The utility model provides a solar cell piece, include:
[0041] Silicon substrate 1, the silicon substrate 1 has opposite first end face and second end face,
[0042] Doped layer 2, be located on the second end face,
[0043] The second end face with doped layer 2 between be equipped with tunneling passivation layer 3, the thickness of tunneling passivation layer 3 decreases from the four peripheral edges of the second end face to the direction of middle.
[0044] It can be understood that the preparation method of the tunneling passivation layer 3 can be atomic layer deposition (ALD), plasma enhanced chemical vapor deposition (PECVD), low-energy oxygen plasma oxidation, thermal oxidation method, etc., but is not limited thereto.
[0045] Due to the steps of laser grooving, hot processing, cell cutting, laminating, etc., these steps are prone to cause stress damage to the tunneling passivation layer 3, and the closer to the edge position of the back surface, the greater the stress damage. In the present application, the thickness of the tunneling passivation layer 3 decreases from the four peripheral edges of the second end face to the direction of the middle, so that the closer to the four peripheral edges of the second end face, the higher the ability of the tunneling passivation layer 3 to withstand and resist stress loss, preventing stress damage from hindering the transport of charge carriers. At the same time, compared to simply increasing the thickness of the entire material layer, the thickness of the tunneling passivation layer 3 in the present application is thinner closer to the middle position of the second end face, ensuring that the tunneling passivation layer 3 not only prevents stress damage from hindering the transport of charge carriers, but also has higher charge carrier transport efficiency as a whole, thereby effectively improving the cell conversion efficiency.
[0046] At the same time, in the actual preparation process, only the growth temperature and the diffusion of the source gas from the four peripheral edges of the second end face to the middle position need to be controlled, so as to form the tunneling passivation layer 3 with the thickness decreasing from the four peripheral edges of the second end face to the direction of the middle. The tunneling passivation layer 3 is easy to produce and manufacture, and is conducive to industrialized production.
[0047] For example, the tunneling passivation layer 3 can be made of silicon oxide.
[0048] For example, the doped layer 2 can be made of polycrystalline silicon.
[0049] The silicon substrate can be P-type monocrystalline silicon, N-type monocrystalline silicon, P-type polycrystalline silicon or N-type polycrystalline silicon, but is not limited to these. Preferably, the silicon substrate is N-type monocrystalline silicon.
[0050] In some embodiments, see Figure 1 As shown, the tunneling passivation layer 3 has a maximum thickness end 31 and a minimum thickness end 32, and the ratio a of the maximum thickness end 31 to the minimum thickness end 32 is 1 < a ≤ 2.7.
[0051] For example, the ratio 'a' of the maximum thickness end 31 to the minimum thickness end 32 can be 1.05, 1.08, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.5, 1.55, 1.6, 1.65, 1.7, 1.75, 1.8, 1.85, 1.9, 1.95, 2.0, 2.05, 2.1, 2.15, 2.2, 2.25, 2.3, 2.35, 2.4, 2.45, 2.5, 2.55, 2.6, 2.65, or 2.7, but is not limited to these. When the ratio 'a' is too large, it can easily affect the flatness of other material layers subsequently set on the tunneling passivation layer 3.
[0052] In some embodiments, the tunneling passivation layer 3 has a maximum thickness end 31 and a minimum thickness end 32, and the ratio a of the maximum thickness end 31 to the minimum thickness end 32 is 1.3≤a≤2.7.
[0053] In some embodiments, the tunneling passivation layer 3 has a maximum thickness end 31 and a minimum thickness end 32, and the ratio a of the maximum thickness end 31 to the minimum thickness end 32 is 1.3≤a≤1.7.
[0054] In some embodiments, the thickness of the maximum thickness end 31 is 1.4 nm to 2.4 nm, and the thickness of the minimum thickness end 32 is 0.8 nm to 1.8 nm. Within this range, the tunneling passivation layer 3 can achieve both better resistance to stress loss and higher carrier transport efficiency, resulting in better overall performance.
[0055] For example, the thickness of the maximum thickness end 31 is 1.4nm, 1.5nm, 1.6nm, 1.7nm, 1.8nm, 1.9nm, 2.0nm, 2.1nm, 2.2nm, 2.3nm or 2.4nm, but is not limited thereto.
[0056] For example, the minimum thickness end 32 has a thickness of 0.8 nm, 0.9 nm, 1.0 nm, 1.1 nm, 1.2 nm, 2.7 nm, 1.4 nm, 1.5 nm, 1.6 nm, 1.7 nm or 1.8 nm, but is not limited thereto. If the thickness of the tunneling passivation layer 3 is too small, the passivation effect is poor and the production difficulty is increased.
[0057] In some embodiments, the thickness of the tunneling passivation layer 3 satisfies the following formula:
[0058]
[0059] In the formula, H(x, y) is the thickness of the tunneling passivation layer 3 at point (x, y) on the second end surface, x and y are the horizontal and vertical distances from the center of the second end surface to point (x, y), 0 < x < 0.5a, 0 < y < 0.5b, H0 is the thickness of the edge of the tunneling passivation layer 3, H c is the thickness of the tunneling passivation layer 3 at the center of the second end surface, k is a constant coefficient and k > 0, a is the length of the tunneling passivation layer 3, b is the width of the tunneling passivation layer 3, β is an adjustment coefficient, and ρ is a deviation coefficient.
[0060] The thickness of the tunneling passivation layer 3 is relatively smoothly transitioned from the four peripheral edges of the second end surface to the middle position, and the overall tunneling passivation layer 3 can balance better anti-stress loss capability and higher carrier transport efficiency, and has better comprehensive performance.
[0061] In some embodiments, referring to Figures 2 to 5 As shown, the tunneling passivation layer 3 is provided with holes opening towards the doped layer 2, and the density of the holes increases with the decrease of the thickness of the tunneling passivation layer 3.
[0062] In the utility model, the holes are arranged on the tunneling passivation layer 3, which can be used as the main transport channel of the carriers. Thus, part of the carriers can directly pass through the tunneling passivation layer 3 by the tunneling characteristic, and part of the carriers are first captured by the holes and then jump to the energy level on the other side by the tunneling process or thermal excitation, and the transport efficiency of the carriers is effectively improved by the cooperation of the transport channel of the holes and the tunneling characteristic of the tunneling passivation layer 3. The sensitivity and dependence of the carrier transport on the ultra-thin thickness of the tunneling passivation layer 3 are reduced, the thickness of the tunneling passivation layer 3 can be relatively thicker, better interface passivation effect can be obtained, and the tunneling passivation layer 3 with better carrier transport efficiency and passivation effect is obtained, and the photoelectric conversion efficiency of the battery is effectively improved.
[0063] Meanwhile, the places where the tunneling passivation layer 3 has a larger thickness are located at the periphery of the second end face, i.e. the places where stress damage is most likely to occur. By setting the density of the holes to decrease with the thickness of the tunneling passivation layer 3, relatively fewer holes are arranged at the places where stress damage is likely to occur, so as to avoid the impact of too many holes on the ability to resist stress damage, and as many holes as possible are arranged at the places where stress impact is small, so that the tunneling passivation layer 3 has more transmission channels on the basis of effectively preventing stress damage from hindering the transportation of carriers, and the overall carrier transmission efficiency is ensured, thereby further improving the battery conversion efficiency.
[0064] In a first embodiment, referring to Figure 3 the doping layer 2 is a first-polarity doping layer 23, and the polarity of the first-polarity doping layer 23 is the same as the polarity of the silicon substrate 1.
[0065] Optionally, referring to Figure 3 a second-polarity doping layer 24 opposite in polarity to the first-polarity doping layer 23 is arranged on the first end face of the silicon substrate 1.
[0066] For example, the silicon substrate 1 is an N-type silicon wafer, the first-polarity doping layer 23 is an N-type doping layer, and the doping concentration of the N-type dopant of the N-type doping layer is greater than that of the N-type silicon wafer, and a P-type doping layer is arranged on the first end face of the silicon substrate 1.
[0067] For example, the silicon substrate 1 is a P-type silicon wafer, the first-polarity doping layer 23 is a P-type doping layer, and the doping concentration of the P-type dopant of the P-type doping layer is greater than that of the P-type silicon wafer, and an N-type doping layer is arranged on the first end face of the silicon substrate 1.
[0068] In a second embodiment, referring to Figures 4 to 5 the doping layer 2 includes N-type doping regions 21 and P-type doping regions 22 arranged alternately and spaced apart,
[0069] the tunneling passivation layer 3 includes an N-region passivation layer 33 arranged inside the N-type doping regions 21 and a P-region passivation layer 34 arranged inside the P-type doping regions 22, the N-region passivation layer 33 is provided with N-region holes 331 open toward the doping layer 2, and the P-region passivation layer 34 is provided with P-region holes 341 open toward the doping layer 2.
[0070] It can be understood that the P-type dopant of the P-type doping regions 22 and the P-type doping layer can be boron, and the N-type dopant of the N-type doping regions 21 and the N-type doping layer can be phosphorus, but is not limited thereto.
[0071] In some embodiments, a passivation layer is arranged on the side of the doping layer 2 away from the tunneling passivation layer 3, and a front surface field, a passivation layer, and an anti-reflection layer are sequentially arranged on the first end face.
[0072] In some embodiments, the density of the N-region holes 331 and / or the P-region holes 341 increases as the thickness of the tunneling passivation layer 3 decreases.
[0073] In some embodiments, referring to Figures 4 to 5 the P-region holes 341 have a density greater than the density of the N-region holes 331.
[0074] Because the hole movement speed is slower than the electron movement speed, by controlling the density of the P-region holes 341 on the corresponding region (P-region passivation layer 34) inside the P-type doped region 22 to be greater than the density of the N-region holes 331 on the corresponding region (N-region passivation layer 33) inside the N-type doped region 21, the number of P-region holes 341 is greater than the number of N-region holes 331, and the holes have more channels, thereby balancing the carriers and further improving the photoelectric conversion efficiency of the cell.
[0075] In some embodiments, the density of the P-region holes 341 is 1 x 10 7 cm -2 ~ 1 x 10 10 cm -2 .
[0076] For example, the density of the P-region holes 341 is 1 x 10 7 cm -2 , 2.5 x 10 7 cm -2 , 5 x 10 7 cm -2 , 8 x 10 7 cm -2 , 1 x 10 8 cm -2 , 2.5 x 10 8 cm -2 , 5 x 10 8 cm -2 , 8 x 10 8 cm -2 , 1 x 10 9 cm -2 , 2.5 x 10 9 cm -2 , 5 x 10 9 cm -2 , 8 x 10 9 cm -2 , or 1 x 10 10 cm -2 , but not limited thereto.
[0077] When the density of the P-region hole 341 is too low, the total number of the P-region hole 341 and the N-region hole 331 is too small, which is difficult to form an effective channel, and affects the carrier transmission efficiency, and when the density of the P-region hole 341 is too high, the passivation effect of the P-region passivation layer 34 is affected.
[0078] In some embodiments, the density of the N-region hole 331 is 1x10 6 cm -2 ~1x10 9 cm -2 .
[0079] For example, the density of the N-region hole 331 is 1x10 6 cm -2 , 2.5x10 6 cm -2 , 5x10 6 cm -2 , 8x10 6 cm -2 , 1x10 7 cm -2 , 2.5x10 7 cm -2 , 5x10 7 cm -2 , 8x10 7 cm -2 , 1x10 8 cm -2 , 2.5x10 8 cm -2 , 5x10 8 cm -2 , 8x10 8 cm -2 , or 1x10 9 cm -2 , but not limited thereto.
[0080] When the density of the N-region hole 331 is too low, it is difficult to form an effective channel, and affects the carrier transmission efficiency, and when the density of the N-region hole 331 is too high, the density of the P-region hole 341 needs to be set higher, which is easy to cause the density of the P-region hole 341 to be too high, and affects the passivation effect of the P-region passivation layer 34.
[0081] The utility model also provides a battery piece is made by the solar cell piece of above -mentioned one kind is divided.
[0082] Among them, the battery piece can be a battery half piece, a quarter piece, but not limited thereto.
[0083] It can be understood that when the battery is divided into a battery half, the cutting edge is located at the position of the original central axis of the battery piece, so the thickness of the tunneling passivation layer 3 increases from the midpoint of the cutting edge of the second end face to the other three edges.
[0084] Secondly, the utility model provides a kind of battery assembly, including above-mentioned solar cell piece.
[0085] Further, the utility model provides a kind of photovoltaic system, including above-mentioned battery assembly.
[0086] The utility model is further described below in conjunction with the drawings and examples:
[0087] Example 1
[0088] Firstly, the utility model provides a kind of solar cell piece, including:
[0089] Silicon substrate, the silicon substrate has opposite first end face and second end face, wherein, second end face is back light surface, silicon substrate is N type monocrystalline silicon,
[0090] Doped layer, is located on the second end face, and doped layer is polycrystalline silicon material,
[0091] Second end face and doped layer between are equipped with tunneling passivation layer, and the thickness of tunneling passivation layer decreases from the four peripheral edges of second end face to the direction of middle.
[0092] Wherein, the doped layer includes N type doped region and P type doped region arranged alternately and interval, and the side of doped layer opposite to tunneling passivation layer is equipped with passivation layer, and first end face is equipped with front surface field, passivation layer and antireflection layer in sequence.
[0093] In the embodiment, the tunneling passivation layer has a maximum thickness end with the maximum thickness and a minimum thickness end with the minimum thickness, and the ratio a of the maximum thickness end to the minimum thickness end is 1.33.
[0094] In the embodiment, the thickness of the maximum thickness end is 2.4 nm, and the thickness of the minimum thickness end is 1.8 nm.
[0095] In the embodiment, the tunneling passivation layer is provided with a hole with an opening facing the doped layer, and the density of the hole increases with the decrease of the thickness of the tunneling passivation layer.
[0096] In the embodiment, the doped layer includes N type doped region and P type doped region arranged alternately and interval,
[0097] The tunneling passivation layer comprises an N region passivation layer arranged in the N type doped region and a P region passivation layer arranged in the P type doped region, the N region passivation layer is provided with an N region hole opening towards the doped layer, and the P region passivation layer is provided with a P region hole opening towards the doped layer.
[0098] In the embodiment, the density of the N region hole and / or the P region hole increases with the decrease of the thickness of the tunneling passivation layer.
[0099] In the embodiment, the density of the P region hole is greater than the density of the N region hole.
[0100] In the embodiment, the density of the P region hole increases from 1*10 7 cm -2 to 5*10 8 cm -2 .
[0101] In the embodiment, the density of the N region hole increases from 1*10 6 cm -2 to 5*10 6 cm -2 .
[0102] Secondly, the utility model provides a battery assembly, including above -mentioned solar cell piece.
[0103] Further, the utility model provides a photovoltaic system, including above -mentioned battery assembly.
[0104] Embodiment 2
[0105] Firstly, the utility model provides a solar cell piece, including:
[0106] Silicon substrate, the silicon substrate has opposite first end surface and second end surface, wherein, second end surface is back light surface, and silicon substrate is N type monocrystalline silicon,
[0107] Doped layer, is arranged on the second end surface, and the doped layer is polycrystalline silicon material,
[0108] The second end surface and the doped layer are provided with a tunneling passivation layer, and the thickness of the tunneling passivation layer decreases from the periphery of the second end surface to the middle.
[0109] Wherein, the doped layer comprises N type doped region and P type doped region arranged alternately, the side of the doped layer away from the tunneling passivation layer is provided with a passivation layer, and the first end surface is sequentially provided with a front surface field, a passivation layer and an anti-reflection layer.
[0110] In the embodiment, the tunneling passivation layer has a maximum thickness end with the maximum thickness and a minimum thickness end with the minimum thickness, and the ratio a of the maximum thickness end to the minimum thickness end is 1.13.
[0111] In the embodiment, the maximum thickness end has a thickness of 1.8 nm, and the minimum thickness end has a thickness of 1.6 nm.
[0112] In the embodiment, the tunneling passivation layer is provided with holes with openings facing the doped layer, and the density of the holes increases with the decrease of the thickness of the tunneling passivation layer.
[0113] In the embodiment, the doped layer comprises N-type doped regions and P-type doped regions arranged alternately and spaced apart,
[0114] The tunneling passivation layer comprises an N-region passivation layer arranged inside the N-type doped regions and a P-region passivation layer arranged inside the P-type doped regions, the N-region passivation layer is provided with N-region holes with openings facing the doped layer, and the P-region passivation layer is provided with P-region holes with openings facing the doped layer.
[0115] In the embodiment, the density of the N-region holes and / or the P-region holes increases with the decrease of the thickness of the tunneling passivation layer.
[0116] In the embodiment, the density of the P-region holes is greater than the density of the N-region holes.
[0117] In the embodiment, the density of the P-region holes increases from 5*10 8 cm -2 to 1*10 9 cm -2 .
[0118] In the embodiment, the density of the N-region holes increases from 5*10 6 cm -2 to 1*10 7 cm -2 .
[0119] Secondly, the utility model provides a kind of battery component, including above-mentioned one solar cell piece.
[0120] Further, the utility model provides a kind of photovoltaic system, including above-mentioned battery component.
[0121] Embodiment 3
[0122] Firstly, the utility model provides a kind of solar cell piece, including:
[0123] A silicon substrate having opposite first and second end faces, wherein the second end face is a back light face, the silicon substrate is an N-type single crystal silicon,
[0124] A doped layer disposed on the second end face, the doped layer is made of polysilicon,
[0125] A tunneling passivation layer is disposed between the second end face and the doped layer, the thickness of the tunneling passivation layer decreases from the periphery of the second end face to the center.
[0126] The doped layer includes N-type doped regions and P-type doped regions arranged alternately and spaced apart, a passivation layer is disposed on the side of the doped layer opposite to the tunneling passivation layer, and a front surface field, a passivation layer and an anti-reflection layer are sequentially disposed on the first end face.
[0127] In this embodiment, the tunneling passivation layer has a maximum thickness end with the maximum thickness and a minimum thickness end with the minimum thickness, and the ratio a of the maximum thickness end to the minimum thickness end is 1.23.
[0128] In this embodiment, the thickness of the maximum thickness end is 1.6 nm, and the thickness of the minimum thickness end is 1.3 nm.
[0129] In this embodiment, the tunneling passivation layer is provided with holes with openings facing the doped layer, and the density of the holes increases with the decrease of the thickness of the tunneling passivation layer.
[0130] The doped layer includes N-type doped regions and P-type doped regions arranged alternately and spaced apart,
[0131] The tunneling passivation layer includes an N-region passivation layer corresponding to the inside of the N-type doped region and a P-region passivation layer corresponding to the inside of the P-type doped region, the N-region passivation layer is provided with N-region holes with openings facing the doped layer, and the P-region passivation layer is provided with P-region holes with openings facing the doped layer.
[0132] In this embodiment, the density of the N-region holes and / or the P-region holes increases with the decrease of the thickness of the tunneling passivation layer.
[0133] In this embodiment, the density of the P-region holes is greater than the density of the N-region holes.
[0134] In this embodiment, the density of the P-region holes decreases from the periphery of the second end face to the center by 1×10 9 cm 9 to 5×10 -2 cm
[0135] In this embodiment, the density of the N-region holes decreases from the periphery of the second end face to the center by 1×10 7 cm-2 increased to 1x10 8 cm -2 .
[0136] Secondly, the utility model provides a battery component, including above -mentioned solar cell piece.
[0137] Further, the utility model provides a photovoltaic system, including above -mentioned battery component.
[0138] Example 4
[0139] Firstly, the utility model provides a solar cell piece, including:
[0140] Silicon substrate, the silicon substrate has opposite first end face and second end face, and the silicon substrate is N type monocrystalline silicon,
[0141] Doped layer, be located on the second end face, and the doped layer is polycrystalline silicon material,
[0142] Second end face and doped layer between be equipped with tunneling passivation layer, and the thickness of tunneling passivation layer decreases from the periphery of second end face to the direction of middle.
[0143] In the embodiment, the tunneling passivation layer has a maximum thickness end with the maximum thickness and a minimum thickness end with the minimum thickness, and the ratio a of the maximum thickness end to the minimum thickness end is 1.23.
[0144] In the embodiment, the thickness of the maximum thickness end is 1.6 nm, and the thickness of the minimum thickness end is 1.3 nm.
[0145] In the embodiment, the tunneling passivation layer is provided with a hole with an opening facing the doped layer, and the density of the hole increases with the decrease of the thickness of the tunneling passivation layer, and the density of the hole of the tunneling passivation layer increases from the periphery of the second end face to the direction of the middle by 1x10 7 cm -2 increased to 1x10 8 cm -2 .
[0146] In the embodiment, the doped layer is a first polarity doped layer, and the polarity of the first polarity doped layer is the same as the polarity of the silicon substrate.
[0147] Wherein, the silicon substrate is an N-type silicon wafer, the first polarity doped layer is an N-type doped layer, and the doping concentration of the N-type dopant of the N-type doped layer is greater than that of the N-type silicon wafer, and the first end face of the silicon substrate is provided with a P-type doped layer.
[0148] Secondly, the utility model provides a battery component, including above -mentioned solar cell piece.
[0149] Further, the utility model provides a photovoltaic system, including above -mentioned battery assembly.
[0150] Embodiment 5
[0151] Firstly, the utility model provides a solar cell piece, including:
[0152] Silicon substrate, the silicon substrate has opposite first end face and second end face, wherein, second end face is back light surface, silicon substrate is N type monocrystalline silicon,
[0153] Doped layer is located on the second end face, and the doped layer is of polysilicon material,
[0154] Tunneling passivation layer is arranged between the second end face and the doped layer, and the thickness of the tunneling passivation layer decreases from the periphery of the second end face to the middle direction.
[0155] Wherein, the doped layer includes N type doped region and P type doped region arranged alternately, the side of the doped layer away from the tunneling passivation layer is provided with a passivation layer, and the first end face is sequentially provided with a front surface field, a passivation layer and an anti-reflection layer.
[0156] In the embodiment, the tunneling passivation layer has a maximum thickness end with the maximum thickness and a minimum thickness end with the minimum thickness, and the ratio a of the maximum thickness end to the minimum thickness end is 1.63.
[0157] In the embodiment, the thickness of the maximum thickness end is 1.3nm, and the thickness of the minimum thickness end is 0.8nm.
[0158] In the embodiment, the tunneling passivation layer is provided with holes with openings facing the doped layer, and the density of the holes increases with the decrease of the thickness of the tunneling passivation layer.
[0159] In the embodiment, the doped layer includes N type doped region and P type doped region arranged alternately,
[0160] The tunneling passivation layer includes N zone passivation layer corresponding to the inside of the N type doped region and P zone passivation layer corresponding to the inside of the P type doped region, the N zone passivation layer is provided with N zone holes with openings facing the doped layer, and the P zone passivation layer is provided with P zone holes with openings facing the doped layer.
[0161] In the embodiment, the density of the N zone holes and / or the P zone holes increases with the decrease of the thickness of the tunneling passivation layer.
[0162] In the embodiment, the density of the P zone holes is greater than the density of the N zone holes.
[0163] In the embodiment, the density of the holes in the P region increases from the four peripheral edges of the second end surface to the middle direction by 5*10 9 cm to 1*10 10 cm -2 .
[0164] In the embodiment, the density of the holes in the N region increases from the four peripheral edges of the second end surface to the middle direction by 1*10 8 cm -2 cm to 1*10 9 cm -2 .
[0165] Secondly, the utility model provides a battery assembly, including above -mentioned solar cell piece.
[0166] Further, the utility model provides a photovoltaic system, including above -mentioned battery assembly.
[0167] Comparative example 1
[0168] Firstly, the utility model provides a solar cell piece, including:
[0169] Silicon substrate, the silicon substrate has opposite first end surface and second end surface, wherein, second end surface is back light surface, silicon substrate is N type monocrystalline silicon,
[0170] Doped layer, be located on the second end surface, and doped layer is polycrystalline silicon material,
[0171] The second end surface with the doped layer between is equipped with tunneling passivation layer, and the thickness of the tunneling passivation layer increases from the four peripheral edges of the second end surface to the middle direction.
[0172] Wherein, the doped layer includes N type doped region and P type doped region arranged alternately, and the side of the doped layer away from the tunneling passivation layer is provided with a passivation layer, and the first end surface is sequentially provided with a front surface field, a passivation layer and an anti-reflection layer.
[0173] In the comparative example, the tunneling passivation layer has a maximum thickness end with a maximum thickness and a minimum thickness end with a minimum thickness, and the ratio a of the maximum thickness end to the minimum thickness end is 1.33.
[0174] In the comparative example, the thickness of the maximum thickness end is 2.4 nm, and the thickness of the minimum thickness end is 1.8 nm.
[0175] In the comparative example, the tunneling passivation layer is provided with holes with an opening facing the doped layer, and the density of the holes increases with the decrease of the thickness of the tunneling passivation layer.
[0176] In the comparative example, the doped layer includes N type doped region and P type doped region arranged alternately,
[0177] The tunneling passivation layer comprises an N region passivation layer arranged inside the N type doped region and a P region passivation layer arranged inside the P type doped region, and the N region passivation layer is provided with an N region hole opening towards the doped layer, and the P region passivation layer is provided with a P region hole opening towards the doped layer.
[0178] In the present comparative example, the density of the N region hole and / or the P region hole increases with the decrease of the thickness of the tunneling passivation layer.
[0179] In the present comparative example, the density of the P region hole is greater than the density of the N region hole.
[0180] In the present comparative example, the density of the P region hole decreases from the four peripheral edges of the second end surface to the middle direction by 5*10 8 cm -2 to 1*10 7 cm -2 .
[0181] In the present comparative example, the density of the N region hole decreases from the four peripheral edges of the second end surface to the middle direction by 5*10 6 cm -2 to 1*10 6 cm -2 .
[0182] Secondly, the utility model provides a kind of battery component, including above-mentioned one solar cell piece.
[0183] Further, the utility model provides a kind of photovoltaic system, including above-mentioned battery component.
[0184] The solar cells prepared in Examples 1 to 5 and Comparative Example 1 are tested for performance, and the test results are as follows:
[0185]
[0186]
[0187] Comparing Examples 1 to 5 with Comparative Example 1, it can be seen that, in the utility model, the thickness of the tunneling passivation layer is arranged to decrease from the four peripheral edges of the second end surface to the middle direction, and the hole of the tunneling passivation layer is correspondingly arranged to increase from the four peripheral edges of the second end surface to the middle direction, which can effectively improve the conversion efficiency of the battery.
[0188] The above merely describes preferred embodiments of the present application and is not intended to limit the present application in any form. Although the present application has been disclosed with preferred embodiments, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above-mentioned technical content without departing from the technical solution of the present application, and equivalent embodiments with equivalent changes are obtained. Any simple modification, equivalent change and modification of the above embodiments based on the technical essence of the present application are still within the scope of the present application.
Claims
1. A solar cell, characterized by, The application relates to a silicon substrate, which comprises: a silicon substrate having opposite first and second end faces, a doped layer provided on the second end face, a tunneling passivation layer is provided between the second end face and the doped layer, and the thickness of the tunneling passivation layer decreases from the periphery of the second end face to the center.
2. The solar cell of claim 1, wherein The tunneling passivation layer has a maximum thickness end with the maximum thickness and a minimum thickness end with the minimum thickness, and the ratio a of the maximum thickness end to the minimum thickness end is 1 3. The solar cell of claim 2, wherein the first and second electrodes are formed of a material selected from the group consisting of silver, aluminum, and copper. The tunneling passivation layer has a maximum thickness end with the maximum thickness and a minimum thickness end with the minimum thickness, and the ratio a of the maximum thickness end to the minimum thickness end is 1.3 4. The solar cell of claim 2, wherein the first and second electrodes are formed of a material selected from the group consisting of silver, aluminum, and copper. The thickness of the maximum thickness end is 1.4-2.4 nm, and the thickness of the minimum thickness end is 0.8-1.8 nm.
5. The solar cell of claim 1, wherein the first and second electrodes are formed of a material selected from the group consisting of silver, aluminum, and copper. The thickness of the tunneling passivation layer satisfies the following formula: where H(x, y) is the thickness of the tunneling passivation layer at point (x, y) on the second end surface, x and y are the horizontal and vertical distances from the center of the second end surface to point (x, y), 0 < x < 0.5a, 0 < y < 0.5b, H0is the thickness of the edge of the tunneling passivation layer, H c is the thickness of the tunneling passivation layer at the center of the second end surface, k is a constant coefficient, and k > 0, a is the length of the tunneling passivation layer, b is the width of the tunneling passivation layer, β is an adjustment coefficient, and ρ is a deviation coefficient.
6. The solar cell of claim 1, wherein the first and second electrodes are formed of a material selected from the group consisting of silver, aluminum, and copper. The tunneling passivation layer is provided with holes with openings facing the doped layer, and the density of the holes increases with the decrease of the thickness of the tunneling passivation layer.
7. The solar cell of claim 6, wherein the first and second conductive layers are formed of a material selected from the group consisting of silver, aluminum, copper, and combinations thereof. The doped layer is a first polarity doped layer, and the polarity of the first polarity doped layer is the same as that of the silicon substrate.
8. The solar cell of claim 6, wherein the back surface is formed of a material having a band gap of 1.0 eV or more. The doped layer comprises N-type doped regions and P-type doped regions arranged alternately and at intervals, The tunneling passivation layer comprises N-region passivation layers provided in the inner sides of the N-type doped regions and P-region passivation layers provided in the inner sides of the P-type doped regions, the N-region passivation layers are provided with N-region holes with openings facing the doped layer, and the P-region passivation layers are provided with P-region holes with openings facing the doped layer.
9. The solar cell of claim 8, wherein the first and second conductive layers are formed of a material selected from the group consisting of silver, aluminum, copper, and combinations thereof. The density of the N-region holes and / or the P-region holes increases with the decrease of the thickness of the tunneling passivation layer.
10. The solar cell of claim 8, wherein the back surface is textured. The density of the P-region holes is greater than that of the N-region holes.
11. The solar cell of claim 8, wherein the back surface is textured. The density of the P region holes is 1 x 10 7 cm -2 ~ 1 x 10 10 cm -2 .
12. The solar cell of claim 8, wherein the back surface is textured. The density of the holes in the N region is 1 x 10 6 cm -2 ~ 1 x 10 9 cm -2 .
13. A battery segment, characterized in that, The application relates to a solar cell piece prepared by cutting a solar cell according to any one of claims 1-12.
14. A battery assembly characterized by, The application relates to a solar cell comprising a solar cell piece according to any one of claims 1-12.
15. A photovoltaic system characterized by, The application relates to a battery assembly comprising a battery piece according to claim 13 or a battery assembly according to claim 14.