Solar cell and preparation method thereof, photovoltaic module

Abstract

The present invention relates to the field of solar cell technology, and discloses a solar cell, a method for preparing the same, and a photovoltaic module. The solar cell comprises a silicon substrate having a light-receiving surface and a light-receiving surface disposed opposite to each other. A first composite passivation layer, a first doped layer, a first transparent conductive layer, and a first electrode are sequentially disposed on the light-receiving surface of the silicon substrate. The first composite passivation layer comprises, along the direction from the silicon substrate to the first transparent conductive layer, a first intrinsic silicon layer, a first passivation layer, a second passivation layer, and a third passivation layer. The second passivation layer and the third passivation layer are prepared using hydrogen and silane. The flow ratio of hydrogen to silane used to prepare the second passivation layer is A1, and the flow ratio of hydrogen to silane used to prepare the third passivation layer is A2, wherein A1 and A2 satisfy the following conditions: 5:1≤A1≤10:1, and 20:1≤A2≤50:1. The solar cell can improve both carrier transport capability and UV resistance.

Description

Technical Field

[0001] The present application relates to the field of solar cell technology, and in particular to a solar cell and a preparation method thereof, and a photovoltaic module. Background Art

[0002] Ultraviolet rays have high energy. If solar cells are exposed to ultraviolet light for a long time, it will not only cause more defects in the solar cells and affect the carrier transmission capacity, but also cause the material performance of the solar cells to degrade, accelerate the aging rate of the solar cells, and make the structural stability of the solar cells worse. Summary of the Invention

[0003] The embodiments of the present invention disclose a solar cell and a preparation method thereof, and a photovoltaic module. Therefore, the solar cell not only has a high anti-ultraviolet effect, but also has a high carrier transmission capacity, thereby improving the structural stability and photoelectric conversion performance of the solar cell.

[0004] In a first aspect, the present application provides a solar cell, comprising: a silicon substrate having a light-receiving surface and a light-receiving surface disposed opposite to each other, wherein a first composite passivation layer, a first doping layer, a first transparent conductive layer, and a first electrode are sequentially disposed on the light-receiving surface of the silicon substrate;

[0005] Wherein, the first composite passivation layer comprises:

[0006] a first intrinsic silicon layer, wherein the first intrinsic silicon layer is disposed on the silicon substrate;

[0007] a first passivation layer, the first passivation layer being provided on a side of the first intrinsic silicon layer facing away from the silicon substrate;

[0008] a second passivation layer, the second passivation layer being disposed on a side of the first passivation layer facing away from the first intrinsic silicon layer;

[0009] a third passivation layer, the third passivation layer being provided on a side of the second passivation layer facing away from the first passivation layer;

[0010] The second passivation layer and the third passivation layer are configured to be prepared by hydrogen and silane, the flow ratio of the hydrogen and the silane used to prepare the second passivation layer is A1, and the flow ratio of the hydrogen and the silane used to prepare the third passivation layer is A2, and A1 and A2 satisfy: 5:1≤A1≤10:1, 20:1≤A2≤50:1.

[0011] Furthermore, A1 and A2 satisfy: A1:A2=(1:10)~(1:2).

[0012] Furthermore, the first passivation layer is configured to be prepared by the hydrogen and the silane, and the flow ratio of the hydrogen to the silane in the first passivation layer is A3, the A3 is less than the A1, and the A3 satisfies: A3≤5:1.

[0013] Furthermore, the thickness of the first passivation layer is H1, the thickness of the second passivation layer is H2, and the thickness of the third passivation layer is H3. H1, H2, and H3 satisfy: H2>H1, H2>H3.

[0014] Furthermore, H1 satisfies: 0 nm

[0015] The H2 satisfies: 3 nm≤H2≤5 nm; and / or,

[0016] The H3 satisfies: 0 nm<H3≤2 nm.

[0017] Furthermore, the crystallization rate of the third passivation layer is 7.5% to 10%, and the crystallization rate of the first doping layer is 10% to 40%.

[0018] Furthermore, the crystallization rate of the first passivation layer is 1% to 5%; and / or,

[0019] The crystallization rate of the second passivation layer is 5% to 7.5%; and / or,

[0020] The thickness of the first intrinsic silicon layer is H4, and H4 satisfies: 0 nm<H4≤0.5 nm.

[0021] Furthermore, a second composite passivation layer, a second doping layer, a second transparent conductive layer, and a second electrode are sequentially provided on the backlight surface of the silicon substrate;

[0022] Wherein, the second composite passivation layer comprises:

[0023] a second intrinsic silicon layer, wherein the second intrinsic silicon layer is disposed on the silicon substrate;

[0024] a fourth passivation layer, the fourth passivation layer being provided on a side of the second intrinsic silicon layer facing away from the silicon substrate;

[0025] The fourth passivation layer is configured to be prepared by the hydrogen and the silane, and a flow ratio of the hydrogen and the silane used to prepare the fourth passivation layer is A4, and the A4 satisfies: 40:1≤A4≤70:1.

[0026] Furthermore, the second composite passivation layer further includes:

[0027] ​a fifth passivation layer, the fifth passivation layer being disposed on a surface of the fourth passivation layer facing away from the silicon substrate;

[0028] a sixth passivation layer, the sixth passivation layer being disposed on a surface of the fifth passivation layer facing away from the silicon substrate;

[0029] The fifth passivation layer and the sixth passivation layer are configured to be prepared by the hydrogen and the silane, the flow ratio of the hydrogen and the silane used to prepare the fifth passivation layer is A5, and the flow ratio of the hydrogen and the silane used to prepare the sixth passivation layer is A6, and the A4, the A5 and the A6 show a downward trend, and the A5 and the A6 satisfy: 30:1≤A5≤60:1, 25:1≤A6≤55:1.

[0030] Furthermore, the thickness of the fourth passivation layer is H5, the thickness of the fifth passivation layer is H6, and the thickness of the sixth passivation layer is H7. H5, H6, and H7 satisfy: H6>H5, H6>H7.

[0031] Furthermore, H5 satisfies: 0 nm<H5≤1 nm; and / or,

[0032] The H6 satisfies: 3 nm≤H6≤5 nm; and / or,

[0033] The H7 satisfies: 0 nm<H7≤1.5 nm.

[0034] Furthermore, the thickness of the second intrinsic silicon layer is H8, and H8 satisfies: 0 nm<H8≤0.5 nm; and / or,

[0035] The thickness of the sixth passivation layer is smaller than the thickness of the third passivation layer.

[0036] In a second aspect, the present invention discloses a method for preparing a solar cell, the method comprising the following steps:

[0037] A first intrinsic silicon layer is prepared on a light-receiving surface of a silicon substrate, a first passivation layer is prepared on the first intrinsic silicon layer, a second passivation layer is prepared on the first passivation layer using hydrogen and silane, and a third passivation layer is prepared on the second passivation layer using the hydrogen and silane to obtain a first composite passivation layer; wherein the flow ratio of the hydrogen and silane used to prepare the second passivation layer is A1, and the flow ratio of the hydrogen and silane used to prepare the third passivation layer is A2, and A1 and A2 satisfy the following conditions: 5:1≤A1≤10:1, 20:1≤A2≤50:1;

[0038] preparing a first doping layer on the third passivation layer;

[0039] preparing a first transparent conductive layer on the first doped layer;

[0040] A first electrode is prepared on the first transparent conductive layer to obtain the solar cell.

[0041] Furthermore, in the step of preparing the first intrinsic silicon layer on the light-receiving surface of the silicon substrate, the preparation parameters include: the process gas includes SiH4, the gas pressure is 0.6 Torr~0.97 Torr, the ignition power is 800 W~1200 W, the ignition time is 1 s~2 s, the ignition time is 1 s~2 s, and the SiH4 flow rate is 800 sccm~1800 sccm; and / or,

[0042] In the step of forming a second passivation layer on the first passivation layer by using hydrogen and silane, the process gases include SiH4 and H2, the gas pressure is 0.5 Torr to 0.57 Torr, the ignition power is 600 W to 800 W, the ignition time is 15 s to 25 s, the flow rate of SiH4 is 600 sccm to 1200 sccm, and the flow rate of H2 is 3000 sccm to 12000 sccm; and / or,

[0043] In the step of preparing a third passivation layer on the second passivation layer by using the hydrogen and the silane, the preparation parameters include: the process gases include SiH4 and H2, the gas pressure is 0.5 Torr~0.57 Torr, the ignition power is 600 W~800 W, the ignition time is 10 s~15 s, the flow rate of SiH4 is 600 sccm~1200 sccm, and the flow rate of H2 is 12000 sccm~60000 sccm.

[0044] Furthermore, the step of preparing a first passivation layer on the first intrinsic silicon layer includes: preparing a first passivation layer on the first intrinsic silicon layer using the hydrogen and the silane, wherein the flow ratio of the hydrogen and the silane in the first passivation layer is A3, the A3 is less than the A1, and the A3 satisfies: A3≤5:1.

[0045] Furthermore, the preparation parameters include: process gases include SiH4 and H2, gas pressure is 0.5 Torr~0.57 Torr, ignition power is 400 W~600 W, ignition time is 2 s~4 s, SiH4 flow rate is 200 sccm~600 sccm, and H2 flow rate is 200 sccm~3000 sccm.

[0046] Furthermore, after the step of preparing the first composite passivation layer and before the step of preparing the first doping layer on the third passivation layer, the method for preparing a solar cell further includes: preparing a second intrinsic silicon layer on the backlight side of the silicon substrate, and preparing a fourth passivation layer on the surface of the second intrinsic silicon layer facing away from the silicon substrate by using the hydrogen and the silane to prepare a second composite passivation layer; wherein the flow ratio of the hydrogen and the silane used to prepare the fourth passivation layer is A4, and A4 satisfies: 40:1≤A4≤70:1.

[0047] Furthermore, in the step of preparing the second intrinsic silicon layer on the backlight surface of the silicon substrate, the preparation parameters include: the process gas includes SiH4, the gas pressure is 0.7 Torr~0.97 Torr, the ignition power is 800 W~1200 W, the ignition time is 1 s~2 s, and the SiH4 flow rate is 800 sccm~1800 sccm; and / or,

[0048] In the step of preparing a fourth passivation layer on the surface of the second intrinsic silicon layer facing away from the silicon substrate using the hydrogen and silane, the preparation parameters include: process gases include SiH4 and H2, gas pressure is 0.5 Torr~0.57 Torr, ignition power is 400 W~600 W, ignition time is 2 s~4 s, SiH4 flow rate is 200 sccm~600 sccm, and H2 flow rate is 8000 sccm~42000 sccm.

[0049] Furthermore, after the step of preparing a fourth passivation layer on the surface of the second intrinsic silicon layer away from the silicon substrate by using the hydrogen and the silane, and before the step of preparing a first doped layer on the third passivation layer, the method for preparing a solar cell also includes: sequentially preparing a fifth passivation layer and a sixth passivation layer on the surface of the fourth passivation layer away from the silicon substrate by using the hydrogen and the silane, wherein the flow ratio of the hydrogen and the silane used to prepare the fifth passivation layer is A5, and the flow ratio of the hydrogen and the silane used to prepare the sixth passivation layer is A6, and A4, A5 and A6 show a downward trend, and A5 and A6 satisfy: 30:1≤A5≤60:1, 25:1≤A6≤55:1.

[0050] Furthermore, in the step of preparing the fifth passivation layer, the preparation parameters include: process gases including SiH4 and H2, gas pressure of 0.5 Torr to 0.57 Torr, ignition power of 600 W to 800 W, ignition time of 15 s to 25 s, SiH4 flow rate of 600 sccm to 1200 sccm, and H2 flow rate of 18000 sccm to 72000 sccm; and / or,

[0051] In the step of preparing the sixth passivation layer, the preparation parameters include: the process gas includes SiH4 and H2, the gas pressure is 0.5 Torr~0.57 Torr, the ignition power is 800 W~1000 W, the ignition time is 5 s~10 s, the SiH4 flow rate is 600 sccm~1200 sccm, and the H2 flow rate is 15000 sccm~66000 sccm.

[0052] Furthermore, after the step of preparing the first doping layer on the third passivation layer and before the step of preparing the first transparent conductive layer on the first doping layer, the method for preparing a solar cell includes: preparing a second doping layer on the second composite passivation layer;

[0053] After the step of preparing the first transparent conductive layer on the first doped layer and before the step of preparing the first electrode on the first transparent conductive layer, the method for preparing a solar cell includes: preparing a second transparent conductive layer on the second doped layer;

[0054] After the step of preparing the first electrode on the first transparent conductive layer, the method for preparing the solar cell includes: preparing the second electrode on the second transparent conductive layer.

[0055] In a third aspect, an embodiment of the present application discloses a photovoltaic module, comprising the solar cell described in the first aspect, or the solar cell prepared by any preparation method described in the second aspect.

[0056] Compared with the prior art, the present invention has the following advantages:

[0057] The present application provides a solar cell, a preparation method thereof, and a photovoltaic module. By arranging a first composite passivation layer on a light-receiving surface and making the first composite passivation layer include a first intrinsic silicon layer and a first passivation layer, a second passivation layer, and a third passivation layer arranged on the first intrinsic silicon layer, and regulating the flow ratio of hydrogen and silane in the second passivation layer and the third passivation layer, the synergistic effect between the layers is high. Therefore, the first composite passivation layer can not only improve the carrier transmission capability, but also increase the content of Si-H bonds in the first composite passivation layer, thereby improving the anti-ultraviolet effect of the solar cell.

[0058] The present application helps to suppress the epitaxial growth of the silicon substrate by setting a first intrinsic silicon layer. And in order to avoid the problems of powder loss and carrier recombination caused by setting the first intrinsic silicon layer. The present application further sets a first passivation layer on the first intrinsic silicon layer, and the first passivation layer can react with the unreacted groups in the first intrinsic silicon layer to avoid the powder loss phenomenon; and a second passivation layer is set on the first passivation layer of the present application, and by A1 in the second passivation layer being within the above range, the hydrogen in the second passivation layer can diffuse into the first passivation layer and the first intrinsic silicon layer, and combine with defects such as dangling bonds in the first passivation layer and the first intrinsic silicon layer, thereby reducing the recombination of carriers and improving the carrier transmission capacity.

[0059] In addition, by setting A1 and A2 within the above range, the second passivation layer and the third passivation layer have a higher matching effect. First, the second passivation layer and the third passivation layer can provide more hydrogen to combine with silicon, which can effectively ensure the Si-H bond content in the first composite passivation layer after ultraviolet light irradiation, so that the second passivation layer and the third passivation layer have a higher anti-ultraviolet effect; secondly, the above range makes hydrogen exist mainly in the form of Si-H bonds, reducing the presence of free hydrogen, thereby avoiding the existence of hydrogen defects caused by excessive hydrogen; finally, by setting A1 and A2 within the above range, the electric field between the second passivation layer and the third passivation layer is more matched, thereby providing a channel that is more conducive to carrier transmission, avoiding the recombination of carriers at the interface due to electric field mutations, and thus helping to improve the performance of solar cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0061] Figure 1 Schematic diagram of the structure of a solar cell provided in an embodiment of the present application (showing an enlarged view of the first composite passivation layer on the light-receiving surface);

[0062] Figure 2 This is a schematic structural diagram of a solar cell provided in an embodiment of the present application (showing an enlarged view of the second composite passivation layer on the backlight side).

[0063] Icon: 1. Silicon substrate; 1a. Light-receiving surface; 1b. Backlight surface; 2. First composite passivation layer; 21. First intrinsic silicon layer; 22. First passivation layer; 23. Second passivation layer; 24. Third passivation layer; 3. First doped layer; 4. First transparent conductive layer; 5. First electrode; 6. Second composite passivation layer; 61. Second intrinsic silicon layer; 62. Fourth passivation layer; 63. Fifth passivation layer; 64. Sixth passivation layer; 7. Second doped layer; 8. Second transparent conductive layer; 9. Second electrode. DETAILED DESCRIPTION

[0064] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0065] In the present invention, terms such as "upper," "lower," "left," "right," "front," "back," "top," "bottom," "inner," "outer," "center," "vertical," "horizontal," "transverse," and "longitudinal" indicate positions or locations based on the positions or locations shown in the accompanying drawings. These terms are primarily intended to better describe the present invention and its embodiments and are not intended to limit the devices, elements, or components indicated to having a specific orientation, or to being constructed or operated in a specific orientation.

[0066] Furthermore, some of the above terms may be used to express other meanings besides indicating a position or location. For example, the term "on" may also be used to indicate a dependency or connection in certain circumstances. Those skilled in the art will understand the specific meanings of these terms in the present invention based on the specific circumstances.

[0067] Furthermore, the terms "first," "second," and the like are primarily used to distinguish different devices, elements, or components (which may or may not be the same in type and configuration) and are not intended to indicate or imply the relative importance or quantity of the devices, elements, or components indicated. Unless otherwise specified, "plurality" means two or more.

[0068] The technical solution provided by the present invention will be further described below with reference to the embodiments and drawings.

[0069] Solar cells are highly sensitive to ultraviolet light. Long-term exposure to ultraviolet light can easily cause the Si-H bonds in the cells to break, generating a large amount of free hydrogen and leading to hydrogen defects. This increases the probability of carrier recombination, which in turn leads to severe degradation of solar cell performance. Furthermore, exposure to ultraviolet light can accelerate the aging of solar cell materials, leading to severe degradation of their performance and significantly impacting their long-term stability.

[0070] In addition, in addition to being affected by ultraviolet light, the silicon substrate of the solar cell material will also have the problem of epitaxial growth. On the one hand, the existence of this epitaxial growth causes the crystal structure of the silicon substrate and the epitaxial layer to be mismatched, resulting in more defects at the interface and aggravated carrier recombination; on the other hand, certain impurity elements in the epitaxial layer will diffuse into the silicon substrate, causing the crystal structure of the silicon substrate to change, thus causing serious material attenuation of the solar cell, affecting the long-term stability and photoelectric conversion performance of the solar cell.

[0071] Based on the above analysis, the embodiments of the present application provide a solar cell and a preparation method thereof, and a photovoltaic module. The solar cell can not only effectively improve the carrier transmission capability, but also effectively improve the anti-ultraviolet effect of the solar cell, so as to promote the extension of the service life of the solar cell and optimize its photoelectric conversion efficiency.

[0072] In a first aspect, the present invention provides a solar cell, such as Figure 1 As shown, the solar cell includes: a silicon substrate 1, the silicon substrate 1 has a light-receiving surface 1a and a backlight surface 1b arranged opposite to each other, and a first composite passivation layer 2, a first doping layer 3, a first transparent conductive layer 4, and a first electrode 5 are sequentially arranged on the light-receiving surface 1a of the silicon substrate 1.

[0073] Wherein, the first composite passivation layer 2 includes:

[0074] A first intrinsic silicon layer 21, wherein the first intrinsic silicon layer 21 is provided on the silicon substrate 1;

[0075] A first passivation layer 22 , which is provided on a side of the first intrinsic silicon layer 21 facing away from the silicon substrate 1 ;

[0076] A second passivation layer 23 , which is provided on a side of the first passivation layer 22 facing away from the first intrinsic silicon layer 21 ;

[0077] A third passivation layer 24 , the third passivation layer 24 is disposed between the second passivation layers 23 and on a side away from the first intrinsic silicon layer 21 ;

[0078] The second passivation layer 23 and the third passivation layer 24 are configured to be prepared by hydrogen and silane. The flow ratio of hydrogen and silane used to prepare the second passivation layer 23 is A1, and the flow ratio of hydrogen and silane used to prepare the third passivation layer 24 is A2. A1 and A2 satisfy: 5:1≤A1≤10:1, 20:1≤A2≤50:1.

[0079] The present application sets a first composite passivation layer 2 on the light-receiving surface of the silicon substrate and utilizes the mutual cooperation between the composite film layers in the first composite passivation layer 2, which helps to improve the anti-ultraviolet effect of the solar cell while improving the carrier transmission capacity, thereby greatly improving the photoelectric conversion performance and service life of the solar cell.

[0080] The present application suppresses the formation of an epitaxial layer on the silicon substrate 1 by providing a first intrinsic silicon layer 21, that is, utilizing the first intrinsic silicon layer 21 to prevent epitaxial growth of the silicon substrate 1. However, the applicant has discovered that some unreacted groups may exist in the first intrinsic silicon layer 21, which may lead to powder loss; and the first intrinsic silicon layer 21 may still contain certain defects, resulting in carrier recombination in the first intrinsic silicon layer 21.

[0081] Therefore, in order to reduce the powder loss and carrier recombination aggravation phenomenon in the first intrinsic silicon layer 21, the present application sets a first passivation layer 22 on the first intrinsic silicon layer 21. The first passivation layer 22 can combine with the unreacted groups in the first intrinsic silicon layer 21, thereby reducing the powder loss phenomenon of the first intrinsic silicon layer 21; in addition, since a second passivation layer 23 is set on the first passivation layer 22, the value of A1 of the second passivation layer 23 is controlled, so that the hydrogen in the second passivation layer 23 can enter the first passivation layer 22 and the first intrinsic silicon layer 21, passivate the defects in the first passivation layer 22 and the first intrinsic silicon layer 21, reduce the recombination of carriers in the first passivation layer 22 and the first intrinsic silicon layer 21, and improve the carrier transmission capacity.

[0082] In addition, by setting A1 and A2 within the above range, the second passivation layer 23 and the third passivation layer 24 have a higher matching effect. First, when ultraviolet rays are irradiated from the light-receiving surface, when they irradiate the first composite passivation layer, they first act on the third passivation layer 24, which easily leads to the breakage of the Si-H bonds in the third passivation layer 24. However, by controlling A2 in the third passivation layer 24 within the above range, the third passivation layer 24 can provide sufficient hydrogen to combine with silicon, thereby ensuring the content of Si-H bonds in the third passivation layer 24; at the same time, part of the ultraviolet light will pass through the third passivation layer 24 and enter the second passivation layer 23. Therefore, by controlling A1 in the second passivation layer 23 within the above range, the second passivation layer 23 can provide sufficient hydrogen to combine with silicon, thereby ensuring the content of Si-H bonds in the second passivation layer 23. In other words, by controlling A1 and A2 in the first composite passivation layer 2 within the above range, the solar cell has a higher anti-ultraviolet effect. Secondly, the above range allows hydrogen to exist primarily in the form of Si-H bonds, reducing the presence of free hydrogen, thereby avoiding the presence of hydrogen defects caused by excessive hydrogen, thereby helping to ensure carrier transport capabilities. Finally, by setting A1 and A2 within the above range, the electric field matching between the second passivation layer 23 and the third passivation layer 24 is highly matched, thereby providing a channel that is more conducive to carrier transport, avoiding the recombination and aggregation of carriers at the interface of the second passivation layer 23 and the third passivation layer 24 due to sudden changes in the electric field, improving carrier transport capabilities, and thus helping to improve the performance of the solar cell.

[0083] In addition, because the second passivation layer 23 is located between the first passivation layer 22 and the third passivation layer 24, the second passivation layer 23 does not need to consider the phenomenon of powder loss of the first intrinsic silicon layer 21, nor does it need to consider the compatibility with the first doped layer 3. Therefore, the third passivation layer 24 can effectively exert its passivation effect, thereby serving as the main passivation layer in the first composite passivation layer 2. By controlling A2 within the above range, it helps to further reduce defects in the third passivation layer 24 and improve the passivation effect of the third passivation layer 24.

[0084] Illustratively, A1 is 5:1, 7:1, 10:1, etc.; A2 is 20:1, 30:1, 50:1, etc.

[0085] The transparent conductive oxide layer is at least one of an indium tin oxide layer, an indium zinc oxide layer, an indium tungsten oxide layer, and an indium cerium oxide layer; and the doped layer includes at least one of a doped microcrystalline silicon layer, a doped polycrystalline silicon layer, and a doped amorphous silicon layer.

[0086] Furthermore, A1 and A2 satisfy the following ratio: A1:A2 = (1:10) to (1:2). When A1:A2 is within the above range, it helps to further enhance the synergy between the second passivation layer 23 and the third passivation layer 24, making the electric field transition between the two more uniform, and further helping to improve the performance of the solar cell.

[0087] Furthermore, the first passivation layer 22 is configured to be prepared by hydrogen and silane, and the flow ratio of hydrogen to silane in the first passivation layer 22 is A3, A3 is less than A1, and A3 satisfies: A3≤5:1.

[0088] By further controlling the flow ratio of hydrogen and silane in the first passivation layer 22, the matching degree of each layer interface is improved and the uniformity of the electric field transition is improved, which helps to reduce the recombination of carriers at the interface and further improve the carrier transmission capacity.

[0089] In addition, when the first passivation layer 22 contains hydrogen, it is more helpful to reduce the defects of the first composite passivation layer 2 and further improve the carrier transmission capacity. Moreover, through the synergistic effect of the three passivation layers, it is also helpful to further improve the anti-ultraviolet effect. Specifically, ultraviolet light will penetrate the third passivation layer 24 and enter the second passivation layer 23 and the first passivation layer 22 in sequence. Therefore, by controlling the contents of A1, A2, and A3 within the above range, the present application ensures to a high degree that each passivation layer contains sufficient hydrogen to combine with silicon, which helps to further improve the anti-ultraviolet effect of the solar cell, thereby reducing the negative impact of ultraviolet rays on the solar cell.

[0090] Illustratively, A3 is 1:1, 3:1, 5:1, etc.

[0091] The thickness of the first passivation layer 22 is H1 , the thickness of the second passivation layer 23 is H2 , and the thickness of the third passivation layer 24 is H3 , where H2 > H1 and H2 > H3 .

[0092] When the thickness relationship satisfies the above range, since the second passivation layer 23 serves as the main passivation layer, the passivation effect of the first composite passivation layer 2 can be effectively ensured by setting the second passivation layer 23 to be thicker.

[0093] Among them, H1 satisfies: 0 nm < H1 ≤ 1 nm; H2 satisfies: 3 nm ≤ H3 ≤ 5 nm; and H3 satisfies: 0 nm < H2 ≤ 2 nm. When the thicknesses meet the above ranges, it helps to ensure the stability of the combination of each layer to a higher degree and achieve better synergy between the layers, thereby helping to further improve the structural stability and photoelectric conversion performance of the solar cell. For example, the thickness of H1 is 0.1 nm, 0.5 nm, 1 nm, etc.; the thickness of H2 is 3 nm, 4 nm, 5 nm, etc.; and the thickness of H3 is 0.1 nm, 1 nm, 1.5 nm, 2 nm, etc.

[0094] Among them, for the first passivation layer 22, when the thickness of the first passivation layer 22 is within the above range, it can effectively act on the first intrinsic silicon layer 21, which can not only reduce the powdering phenomenon of the first intrinsic silicon layer 21 to a large extent, but also help to further reduce the series resistance of the first passivation layer 22; for the third passivation layer 24, the contact performance with the first doped layer 3 is better at this thickness, which helps to better transmit carriers at the interface.

[0095] In addition, the thickness of the film layer mentioned in this application refers to the average thickness of the film layer. Taking the thickness of the first passivation layer 22 as an example, it is a value obtained by calculating the thickness values ​​measured at multiple positions of the first passivation layer 22. It reflects the overall thickness level of the first passivation layer 22 in the thickness direction.

[0096] For example, an ellipsometer can be used to test the thickness of the first passivation layer 22. Taking the measurement of the thickness of the first passivation layer 22 as an example, at least five points can be taken on the first passivation layer 22, and the thickness values ​​of these five points can be measured using an ellipsometer. Then, the average value of the thickness values ​​of these five points is calculated to obtain the thickness of the first passivation layer 22. Among them, the ellipsometer can be an ellipsometer manufactured by the German company sentch, model SE-800. This application does not limit the thickness testing instrument and specific method, as long as it can achieve the purpose of this application.

[0097] Furthermore, the crystallization rate of the third passivation layer 24 is 7.5% to 10%, and the crystallization rate of the first doping layer 3 is 10% to 40%.

[0098] When the crystallization ratios of the third passivation layer 24 and the first doped layer 3 are within the above ranges, the crystals of the third passivation layer 24 and the first doped layer 3 are more closely matched, and their work functions are more closely matched, thereby significantly improving the performance of the solar cell. For example, the crystallization ratio of the third passivation layer 24 is 7.5%, 8%, 9%, 10%, etc.; and the crystallization ratio of the first doped layer 3 is 10%, 20%, 30%, 40%, etc.

[0099] Furthermore, the crystallization rate of the first passivation layer 22 is 1% to 5%, and the crystallization rate of the second passivation layer 23 is 5% to 7.5%. When the crystallization rates of the first passivation layer 22 and the second passivation layer 23 are within the above ranges, it helps to significantly improve the matching between the first passivation layer 22, the second passivation layer 23, and the third passivation layer 24, further reducing carrier recombination at the interface.

[0100] For example, the crystallization rate of the first passivation layer 22 is 1%, 3%, 5%, etc.; the crystallization rate of the second passivation layer 23 is 5%, 6%, 7.5%, etc.

[0101] Furthermore, the first intrinsic silicon layer 21 has a thickness H4, where H4 satisfies the following relationship: 0 nm < H4 ≤ 0.5 nm. When the thickness of H4 is within this range, it helps provide a high anti-epitaxial effect and improves the performance of the solar cell. For example, the thickness of H4 is 0.1 nm, 0.3 nm, 0.5 nm, etc.

[0102] Furthermore, if Figure 2 As shown, a second composite passivation layer 6 , a second doping layer 7 , a second transparent conductive layer 8 , and a second electrode 9 are sequentially arranged on the backlight surface 1 b of the silicon substrate 1 .

[0103] Wherein, the second composite passivation layer 6 includes:

[0104] A second intrinsic silicon layer 61, the second intrinsic silicon layer 61 is provided on the silicon substrate 1;

[0105] a fourth passivation layer 62 , which is disposed on a side of the second intrinsic silicon layer 61 facing away from the silicon substrate 1 ;

[0106] The fourth passivation layer 62 is configured to be prepared by hydrogen and silane. The flow ratio of hydrogen and silane used to prepare the fourth passivation layer 62 is A4, and A4 satisfies: 40:1≤A4≤70:1.

[0107] The present application provides a second intrinsic silicon layer 61 on the backlight surface 1b of the silicon substrate 1. The presence of the second intrinsic silicon layer 61 can prevent the epitaxial growth of the silicon substrate 1. By further providing a fourth passivation layer 62 on the second intrinsic silicon layer 61, the fourth passivation layer 62 can combine with the unreacted groups in the second intrinsic silicon layer 61, thereby avoiding the phenomenon of powder loss and ensuring the effectiveness of the second intrinsic silicon layer 61. In addition, the present application sets A4 within the above-mentioned range so that part of the hydrogen diffuses into the second intrinsic silicon layer 61. The hydrogen diffused into the second intrinsic silicon layer 61 can both passivate the defects within the second intrinsic silicon layer 61 and contact the silicon substrate 1, thereby helping to passivate the silicon substrate 1 and improving the passivation effect of the backlight surface 1b of the solar cell.

[0108] According to the above records, this application helps to ensure the anti-ultraviolet effect of the solar cell to a high degree by controlling A1 of the second passivation layer 23 of the light-receiving surface and A4 in the third passivation layer; however, the above-mentioned setting of the light-receiving surface 1a may cause the passivation effect of the light-receiving surface 1a to be affected. Therefore, this application helps to improve the passivation effect of the backlight surface 1b by further controlling A4 in the fourth passivation layer of the backlight surface 1b, thereby improving the overall performance of the solar cell. That is, the solar cell provided by this application has improved the performance of both the light-receiving surface 1a and the backlight surface 1b, which not only optimizes the anti-ultraviolet effect of the light-receiving surface 1a and ensures the long-term stability of the solar cell material; but also improves the passivation effect of the backlight surface 1b and reduces the recombination of carriers, thereby improving the performance of the solar cell to a high degree.

[0109] The doping types of the first doping layer 3 and the second doping layer 7 are opposite. One of the first doping layer 3 and the second doping layer 7 is an N-type doping layer, and the other is a P-type doping layer.

[0110] Further, see Figure 2 , the second composite passivation layer 6 further includes:

[0111] a fifth passivation layer 63 , the fifth passivation layer 63 being disposed on a surface of the fourth passivation layer 62 facing away from the silicon substrate 1 ;

[0112] a sixth passivation layer 64 , which is disposed on a surface of the fifth passivation layer 63 facing away from the silicon substrate 1 ;

[0113] The fifth passivation layer 63 and the sixth passivation layer 64 are configured to be prepared by hydrogen and silane. The flow ratio of hydrogen and silane used to prepare the fifth passivation layer 63 is A5, and the flow ratio of hydrogen and silane used to prepare the sixth passivation layer 64 is A6. A4, A5, and A6 show a downward trend, and A5 and A6 satisfy: 30:1≤A5≤60:1, 25:1≤A6≤55:1.

[0114] This application further provides a fifth passivation layer 63 and a sixth passivation layer 64 on the fourth passivation layer 62. Since the fifth passivation layer 63 is located between the sixth passivation layer 64 and the fourth passivation layer 62, the fifth passivation layer 63 does not need to consider how to prevent yellowing of the second intrinsic silicon layer 61, nor does it need to consider contact with the second doped layer 7. Therefore, the fifth passivation layer 63 can effectively exert its passivation effect, thereby serving as the main passivation layer in the second composite passivation layer 6, ensuring the passivation effect of the second composite passivation layer 6. Furthermore, by controlling their flow ratio within the above range, a high synergistic effect is achieved between the fourth passivation layer 62, the fifth passivation layer 63, and the sixth passivation layer 64, which helps further enhance the passivation effect of the backlight surface 1b and improve the photoelectric conversion efficiency of the solar cell. For example, A5 is 30:1, 55:1, 60:1, etc.; A6 is 25:1, 45:1, 55:1, etc.

[0115] Furthermore, the thickness of the fourth passivation layer 62 is H5, the thickness of the fifth passivation layer 63 is H6, and the thickness of the sixth passivation layer 64 is H7. H5, H6, and H7 satisfy: H6>H5, H6>H7.

[0116] In addition, since the fifth passivation layer 63 serves as the main passivation layer of the second composite passivation layer 6 , providing the fifth passivation layer 63 with a relatively high thickness can help further improve the passivation effect of the second composite passivation layer 6 .

[0117] Here, H5 satisfies: 0 nm < H5 ≤ 1 nm; H6 satisfies: 3 nm ≤ H6 ≤ 5 nm; and H7 satisfies: 0 nm < H7 ≤ 1.5 nm. When the thickness is within the above range, the fourth passivation layer 62 achieves a better match and synergistic effect with the fifth and sixth passivation layers 63 and 64, helping to further improve the performance of the solar cell. For example, the thickness of H5 is 0.1 nm, 0.5 nm, 1 nm, etc.; the thickness of H3 is 3 nm, 4 nm, 5 nm, etc.; and the thickness of H6 is 0.1 nm, 1 nm, 1.5 nm, etc.

[0118] Furthermore, the second intrinsic silicon layer 61 has a thickness of H8, which satisfies the following relationship: 0 nm < H8 ≤ 0.5 nm. A thickness of H8 within the above range helps provide a higher anti-epitaxial effect. For example, H8 is 0.2 nm, 0.4 nm, 0.5 nm, etc.

[0119] Furthermore, the thickness of the sixth passivation layer 64 is less than the thickness of the third passivation layer 24. In the solution of the present application, the third passivation layer 24 is located on the light-receiving surface 1a and is arranged close to the first doped layer 3, and the third passivation layer 24 has a high contact performance with the first doped layer 3; while the sixth passivation layer 64 is arranged on the backlight surface 1b and has a poor contact performance with the second doped layer 7. Therefore, by setting the thickness of the sixth passivation layer 64 to be less than the thickness of the second passivation layer 23, on the one hand, it helps to reduce the poor contact performance between the sixth passivation layer 64 and the second doped layer 7 due to crystal mismatch; on the other hand, the thicker third passivation layer 24 can ensure the UV protection effect of the solar cell to a higher degree and improve its contact performance with the first doped layer 3.

[0120] In a second aspect, the present invention discloses a method for preparing a solar cell, the method comprising the following steps:

[0121] A first intrinsic silicon layer is formed on a light-receiving surface of a silicon substrate, a first passivation layer is formed on the first intrinsic silicon layer, a second passivation layer is formed on the first passivation layer using hydrogen and silane, and a third passivation layer is formed on the second passivation layer using hydrogen and silane to obtain a first composite passivation layer; wherein the flow ratio of hydrogen and silane used to prepare the second passivation layer is A1, and the flow ratio of hydrogen and silane used to prepare the third passivation layer is A2, and A1 and A2 satisfy the following conditions: 5:1≤A1≤10:1, 20:1≤A2≤50:1;

[0122] forming a first doping layer on the third passivation layer;

[0123] forming a first transparent conductive layer on the first doped layer;

[0124] A first electrode is prepared on the first transparent conductive layer to produce a solar cell.

[0125] Among them, in the step of preparing the first intrinsic silicon layer on the light-receiving surface of the silicon substrate, the preparation parameters include: the process gas includes SiH4, the gas pressure is 0.6 Torr~0.97 Torr, the ignition power is 800 W~1200 W, the ignition time is 1 s~2 s, and the SiH4 flow rate is 800 sccm~1800 sccm.

[0126] In the step of preparing a second passivation layer on the first passivation layer by hydrogen and silane, the process gases include SiH4 and H2, the gas pressure is 0.5 Torr~0.57 Torr, the ignition power is 600 W~800 W, the ignition time is 15 s~25 s, the flow rate of SiH4 is 600 sccm~1200 sccm, and the flow rate of H2 is 3000 sccm~12000 sccm.

[0127] Among them, in the step of preparing a third passivation layer on the second passivation layer by hydrogen and silane, the preparation parameters include: the process gases include SiH4 and H2, the gas pressure is 0.5 Torr~0.57 Torr, the ignition power is 600 W~800 W, the ignition time is 10 s~15 s, the flow rate of SiH4 is 600 sccm~1200 sccm, and the flow rate of H2 is 12000 sccm~60000 sccm.

[0128] In this preparation method, compared with the first passivation layer, the first intrinsic silicon layer is prepared at a higher power, resulting in a larger number of unreacted groups and a more serious powdering phenomenon. Therefore, the first passivation layer is deposited on the first intrinsic silicon layer so that the first passivation layer is combined with the unreacted groups in the first intrinsic silicon layer, thereby avoiding the phenomenon of the unreacted groups turning into yellow powder.

[0129] By controlling the preparation parameters within the above range, the quality of the obtained film layer can be ensured to be high, thereby achieving good matching between the layers and helping to improve the performance of the solar cell.

[0130] Furthermore, the step of preparing a first passivation layer on the first intrinsic silicon layer includes: preparing the first passivation layer on the first intrinsic silicon layer by hydrogen and silane, wherein the flow ratio of hydrogen and silane in the first passivation layer is A3, A3 is less than A1, and A3 satisfies: A3≤5:1.

[0131] Among them, the preparation parameters include: process gases include SiH4 and H2, gas pressure is 0.5 Torr~0.57 Torr, ignition power is 400 W~600 W, ignition time is 2 s~4 s, SiH4 flow rate is 200 sccm~600 sccm, and H2 flow rate is 200 sccm~3000 sccm.

[0132] By controlling the preparation parameters of the first passivation layer within the above ranges, the film quality of the first passivation layer is improved, thereby helping to ensure the anti-epitaxial effect of the first passivation layer.

[0133] Furthermore, after the step of preparing the first composite passivation layer and before the step of preparing the first doping layer on the third passivation layer, the method for preparing a solar cell also includes: preparing a second intrinsic silicon layer on the backlight side of the silicon substrate, and preparing a fourth passivation layer on the surface of the second intrinsic silicon layer facing away from the silicon substrate using hydrogen and silane to prepare a second composite passivation layer; wherein the flow ratio of hydrogen and silane used to prepare the fourth passivation layer is A4, and A4 satisfies: 40:1≤A4≤70:1.

[0134] Among them, in the step of preparing the second intrinsic silicon layer on the backlight surface of the silicon substrate, the preparation parameters include: the process gas includes SiH4, the gas pressure is 0.7 Torr~0.97 Torr, the ignition power is 800 W~1200 W, the ignition time is 1 s~2 s, and the SiH4 flow rate is 800 sccm~1800 sccm.

[0135] In the step of preparing a fourth passivation layer on the second intrinsic silicon layer away from the silicon substrate using hydrogen and silane, the preparation parameters include: process gases including SiH4 and H2, gas pressure of 0.5 Torr~0.57 Torr, ignition power of 400 W~600 W, ignition time of 2 s~4 s, SiH4 flow rate of 200 sccm~600 sccm, and H2 flow rate of 8000 sccm~42000 sccm.

[0136] In this preparation method, compared with the fourth passivation layer, the second intrinsic silicon layer has a higher power during preparation, so the number of unreacted groups is larger. Therefore, the first passivation layer is deposited on the second intrinsic silicon layer, so that the fourth passivation layer reacts with the unreacted groups in the second intrinsic silicon layer, thereby avoiding the phenomenon that the unreacted groups turn into yellow powder; and by controlling the preparation parameters of the fourth passivation layer within the above range, the passivation effect of the fourth passivation layer is higher, thereby improving the passivation effect of the backlight surface of the solar cell to a greater extent.

[0137] Furthermore, after the step of preparing a fourth passivation layer on the surface of the second intrinsic silicon layer facing away from the silicon substrate using hydrogen and silane, and before the step of preparing a first doped layer on the third passivation layer, the method for preparing a solar cell also includes: sequentially preparing a fifth passivation layer and a sixth passivation layer on the surface of the fourth passivation layer facing away from the silicon substrate using hydrogen and silane, wherein the flow ratio of hydrogen and silane used to prepare the fifth passivation layer is A5, and the flow ratio of hydrogen and silane used to prepare the sixth passivation layer is A6, A4, A5, and A6 show a downward trend, and A5 and A6 satisfy: 30:1≤A5≤60:1, 25:1≤A6≤55:1.

[0138] Among them, in the step of preparing the fifth passivation layer, the preparation parameters include: the process gas includes SiH4 and H2, the gas pressure is 0.5 Torr~0.57 Torr, the ignition power is 600 W~800 W, the ignition time is 15 s~25 s, the SiH4 flow rate is 600 sccm~1200 sccm, and the H2 flow rate is 18000 sccm~72000 sccm.

[0139] In the step of preparing the sixth passivation layer, the preparation parameters include: the process gases include SiH4 and H2, the gas pressure is 0.5 Torr~0.57 Torr, the ignition power is 800 W~1000 W, the ignition time is 5 s~10 s, the flow rate of SiH4 is 600 sccm~1200 sccm, and the flow rate of H2 is 15000 sccm~66600 sccm.

[0140] By controlling the preparation parameters within the above range, it helps to ensure that the film quality of the prepared fifth passivation layer and the sixth passivation layer is high, thereby improving the passivation effect of the backlight surface of the solar cell to a high degree.

[0141] Furthermore, after the step of preparing the first doping layer on the third passivation layer and before the step of preparing the first transparent conductive layer on the first doping layer, the method for preparing a solar cell includes: preparing a second doping layer on the second composite passivation layer;

[0142] After the step of forming a first transparent conductive layer on the first doped layer and before the step of forming a first electrode on the first transparent conductive layer, the method for preparing a solar cell includes: forming a second transparent conductive layer on the second doped layer;

[0143] After the step of preparing the first electrode on the first transparent conductive layer, the method for preparing the solar cell includes: preparing the second electrode on the second transparent conductive layer.

[0144] In a third aspect, an embodiment of the present application further discloses a photovoltaic module, comprising: the solar cell of the first aspect, or the solar cell prepared by the preparation method of the second aspect.

[0145] The technical solution of the present application will be further explained below in conjunction with more specific embodiments and experimental test results.

[0146] Example 1:

[0147] The N-type silicon substrate is textured.

[0148] Prepare the first composite passivation layer on the light-receiving surface of the silicon substrate:

[0149] A first intrinsic silicon layer with a thickness of 0.3 nm was prepared using SiH4 as the process gas with a SiH4 flow rate of 1000 sccm, a gas pressure of 0.7 Torr, a starting power of 900 W, and a starting time of 1.5 s.

[0150] A first passivation layer with a thickness of 0.7 nm and a crystallinity of 4% was prepared using SiH4 and H2 gas at a pressure of 0.55 Torr, a starting power of 500 W, a starting time of 3 s, an A3 ratio of 3:1, a SiH4 flow rate of 500 sccm, and a H2 flow rate of 1500 sccm.

[0151] A second passivation layer with a thickness of 4 nm and a crystallization rate of 7% was prepared: the process gases included SiH4 and H2, the gas pressure was 0.55 Torr, the ignition power was 700 W, the ignition time was 20 s, the A1 was 8:1, the SiH4 flow rate was 1000 sccm, and the H2 flow rate was 8000 sccm;

[0152] A third passivation layer with a thickness of 1 nm and a crystallization rate of 8.5% was prepared: the process gases included SiH4 and H2, the gas pressure was 0.55 Torr, the ignition power was 700 W, the ignition time was 10 s, A2 was 40:1, the flow rate of SiH4 was 1000 sccm, and the flow rate of H2 was 40000 sccm.

[0153] Prepare a second composite passivation layer on the backlight side of the silicon substrate:

[0154] A second intrinsic silicon layer with a thickness of 0.3 nm was prepared using SiH4 as the process gas, a gas pressure of 0.85 Torr, a starting power of 1000 W, a starting time of 1.5 s, and a SiH4 flow rate of 1000 sccm.

[0155] A fourth passivation layer with a thickness of 0.5 nm was prepared using SiH4 and H2 as process gases, a gas pressure of 0.56 Torr, a starting power of 500 W, a starting time of 3 s, an A4 ratio of 60:1, a SiH4 flow rate of 500 sccm, and a H2 flow rate of 30,000 sccm.

[0156] A fifth passivation layer with a thickness of 4 nm was prepared using SiH4 and H2 as process gases, a gas pressure of 0.55 Torr, a starting power of 700 W, a starting time of 20 s, an A5 ratio of 45:1, a SiH4 flow rate of 1000 sccm, and a H2 flow rate of 45,000 sccm.

[0157] A sixth passivation layer with a thickness of 1 nm was prepared: the process gases included SiH4 and H2, the gas pressure was 0.55 Torr, the ignition power was 900 W, the ignition time was 7 s, A6 was 35:1, the flow rate of SiH4 was 1000 sccm, and the flow rate of H2 was 35000 sccm.

[0158] Preparation of a first doped layer on the third passivation layer: An N-type doped layer was prepared on the third passivation layer by a PECVD method with a gas pressure of 5 Torr, a flow ratio of SiH4, doping gas, and H2 in the process gas of 1:3:250, a starting power of 7000 W, a starting time of 175 s, and a crystallization rate of the first doped layer of 15%.

[0159] A second doped layer was prepared on the second composite passivation layer: a P-type doped layer was prepared on the first composite passivation layer by a PECVD method, the gas pressure was 5 Torr, the flow ratio of SiH4, doping gas and H2 in the process gas was 1:3:250, the starting power was 7000 W, and the starting time was 175 s.

[0160] A first transparent conductive layer is formed on the first doping layer.

[0161] A second transparent conductive layer is formed on the second doping layer.

[0162] A first electrode is formed on the first transparent conductive layer.

[0163] A second electrode is formed on the second transparent conductive layer.

[0164] Example 2:

[0165] The only difference between this embodiment and the first embodiment is that A3 of the first passivation layer is 8:1.

[0166] Example 3:

[0167] The only difference between this embodiment and the first embodiment is that the second composite passivation layer is a conventional film structure, that is, the film structure includes an intrinsic silicon layer and a passivation layer arranged on the intrinsic silicon layer, and the flow ratio of hydrogen and silane in the passivation layer is 1:1.

[0168] Example 4:

[0169] The only difference between this embodiment and the first embodiment is that A4 of the fourth passivation layer is 35:1.

[0170] Embodiment 5:

[0171] The only difference between this embodiment and the first embodiment is that A4 of the fourth passivation layer is 75:1.

[0172] Comparative Example 1:

[0173] The difference between this comparative example and Example 1 is that the ratio of A1 in the second passivation layer in Comparative Example 1 is 4:1.

[0174] Comparative Example 2:

[0175] The difference between this comparative example and Example 1 is that the ratio of A1 in the second passivation layer in Comparative Example 1 is 12:1.

[0176] Comparative Example 3:

[0177] The difference between this comparative example and Example 1 is that the ratio of A2 in the third passivation layer in Comparative Example 1 is 18:1.

[0178] Comparative Example 4:

[0179] The difference between this comparative example and Example 1 is that the ratio of A2 in the third passivation layer in Comparative Example 1 is 52:1.

[0180] Performance Testing

[0181] The following tests were performed on the solar cells prepared in Examples 1 to 5 and Comparative Examples 1 to 4:

[0182] This application uses a GIV-60 tester manufactured by Zhongsen Electric Technology Co., Ltd. to test the solar cell's open-circuit voltage, short-circuit current, and fill factor. The silicon wafer used for the test was 210 mm × 105 mm, and the calibrated light intensity was 1000 ± 5 W / m². The test results are as follows.

[0183] Table 1 Performance test results of solar cells

[0184]

[0185] Analysis of the data from Example 1, Comparative Example 1, and Comparative Example 2 shows that Example 1 has superior photoelectric conversion performance to Comparative Examples 1 and 2. This is because the ratio of A1 in Example 1 is within the range of 5:1 to 8:1. Within this range, the second passivation layer can provide sufficient hydrogen to enter the first passivation layer and the first intrinsic silicon layer, thereby passivating defects in the first passivation layer and the first intrinsic silicon layer and improving the carrier transport capacity in the first passivation layer and the first intrinsic silicon layer. Furthermore, the matching degree between A1 and A2 is high, thereby contributing to a high degree of improvement in the UV resistance of the solar cell, ensuring high uniformity of the electric field transition in the second and third passivation layers, and promoting carrier transport at the interface between the second and third passivation layers.

[0186] Analysis of the data from Example 1, Comparative Examples 3, and 4 shows that Example 1 exhibits superior photoelectric conversion performance to Comparative Examples 3 and 4. This is because the ratio of A2 in Example 1 is within the range of 20:1 to 50:1. This range not only provides a high degree of matching between A2 and A1, significantly improving the solar cell's UV resistance, but also ensures high uniformity in the electric field transition in the second and third passivation layers.

[0187] Analysis of the data from Examples 1 and 2 shows that Example 1 has better photoelectric conversion performance than Example 2. This is because A1 and A3 in Example 1 are more closely matched. This results in a higher degree of matching between the electric fields of the first passivation layer and the second passivation layer, which helps further reduce the potential barrier for carriers to propagate at the interface, significantly improving carrier transport performance and thus further enhancing the performance of the solar cell.

[0188] Analysis of the data of Example 1 and Example 3 shows that the photoelectric conversion performance of Example 1 is better than that of Example 3. This is because the A4 ratio in the fourth passivation layer on the backlight surface of Example 1 is 60:1. Therefore, the fourth passivation layer can provide a sufficient amount of hydrogen to enter the second intrinsic silicon layer, thereby allowing the hydrogen entering the second intrinsic silicon layer to contact the backlight surface of the silicon substrate, passivating the backlight surface of the silicon substrate, and helping to further improve the passivation effect of the backlight surface, effectively promoting the improvement of the photoelectric conversion performance of the solar cell. In addition, the fourth passivation layer in Example 1 is also provided with a fifth passivation layer and a sixth passivation layer. Therefore, the coordinated cooperation of these passivation layers helps to further improve the passivation effect of the backlight surface of the silicon substrate.

[0189] Analysis of the data from Examples 1, 4, and 5 shows that Example 1 outperforms Examples 4 and 5 because the A4 ratio in Example 1 is within the range of 40:1 to 70:1. Therefore, Example 1 can provide an appropriate amount of hydrogen to enter the second intrinsic silicon layer, thereby contacting the backlight surface of the silicon substrate, further passivating the backlight surface of the silicon substrate and further improving the passivation performance of the backlight surface.

[0190] The above is a detailed introduction to the solar cells, preparation methods and photovoltaic modules disclosed in the embodiments of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the solar cells, preparation methods and photovoltaic modules. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the contents of this specification should not be understood as limiting the present invention.

Claims

1. A solar cell, characterized in that: The solar cell comprises: a silicon substrate, the silicon substrate having a light-receiving surface and a light-receiving surface disposed opposite to each other, a first composite passivation layer, a first doping layer, a first transparent conductive layer, and a first electrode disposed in sequence on the light-receiving surface of the silicon substrate, wherein the first doping layer is an N-type doping layer; Wherein, the first composite passivation layer comprises: a first intrinsic silicon layer, wherein the first intrinsic silicon layer is disposed on the silicon substrate; a first passivation layer, the first passivation layer being provided on a side of the first intrinsic silicon layer facing away from the silicon substrate; a second passivation layer, the second passivation layer being disposed on a side of the first passivation layer facing away from the first intrinsic silicon layer; a third passivation layer, the third passivation layer being provided on a side of the second passivation layer facing away from the first passivation layer; The second passivation layer and the third passivation layer are configured to be prepared by hydrogen and silane, the flow ratio of the hydrogen and the silane used to prepare the second passivation layer is A1, and the flow ratio of the hydrogen and the silane used to prepare the third passivation layer is A2, and A1 and A2 satisfy: 5:1≤A1≤10:1, 20:1≤A2≤50:

1.

2. The solar cell according to claim 1, characterized in that A1 and A2 satisfy: A1:A2=(1:10)~(1:2).

3. The solar cell according to claim 1, wherein The first passivation layer is configured to be prepared by the hydrogen and the silane, and a flow ratio of the hydrogen to the silane in the first passivation layer is A3, the A3 is less than the A1, and the A3 satisfies: A3≤5:

1.

4. The solar cell according to claim 1, wherein The thickness of the first passivation layer is H1, the thickness of the second passivation layer is H2, and the thickness of the third passivation layer is H3. H1, H2, and H3 satisfy: H2>H1, H2>H3.

5. The solar cell according to claim 4, characterized in that The H1 satisfies: 0 nm<H1≤1 nm; and / or, The H2 satisfies: 3 nm≤H2≤5 nm; and / or, The H3 satisfies: 0 nm<H3≤2 nm.

6. The solar cell according to claim 1, wherein The crystallization rate of the third passivation layer is 7.5% to 10%, and the crystallization rate of the first doping layer is 10% to 40%.

7. The solar cell according to any one of claims 1 to 6, characterized in that: The crystallization rate of the first passivation layer is 1% to 5%; and / or, The crystallization rate of the second passivation layer is 5% to 7.5%; and / or, The thickness of the first intrinsic silicon layer is H4, and H4 satisfies: 0 nm<H4≤0.5 nm.

8. The solar cell according to claim 1, wherein A second composite passivation layer, a second doping layer, a second transparent conductive layer, and a second electrode are sequentially arranged on the backlight surface of the silicon substrate; Wherein, the second composite passivation layer comprises: a second intrinsic silicon layer, wherein the second intrinsic silicon layer is disposed on the silicon substrate; a fourth passivation layer, the fourth passivation layer being provided on a side of the second intrinsic silicon layer facing away from the silicon substrate; The fourth passivation layer is configured to be prepared by the hydrogen and the silane, and a flow ratio of the hydrogen and the silane used to prepare the fourth passivation layer is A4, and the A4 satisfies: 40:1≤A4≤70:

1.

9. The solar cell according to claim 8, characterized in that The second composite passivation layer further comprises: a fifth passivation layer, the fifth passivation layer being disposed on a surface of the fourth passivation layer facing away from the silicon substrate; a sixth passivation layer, the sixth passivation layer being disposed on a surface of the fifth passivation layer facing away from the silicon substrate; The fifth passivation layer and the sixth passivation layer are configured to be prepared by the hydrogen and the silane, the flow ratio of the hydrogen and the silane used to prepare the fifth passivation layer is A5, and the flow ratio of the hydrogen and the silane used to prepare the sixth passivation layer is A6, and the A4, the A5 and the A6 show a downward trend, and the A5 and the A6 satisfy: 30:1≤A5≤60:1, 25:1≤A6≤55:

1.

10. The solar cell according to claim 9, characterized in that The thickness of the fourth passivation layer is H5, the thickness of the fifth passivation layer is H6, and the thickness of the sixth passivation layer is H7. H5, H6, and H7 satisfy: H6>H5, H6>H7.

11. The solar cell according to claim 10, characterized in that The H5 satisfies: 0 nm<H5≤1 nm; and / or, The H6 satisfies: 3 nm≤H6≤5 nm; and / or, The H7 satisfies: 0 nm<H7≤1.5 nm.

12. The solar cell according to any one of claims 9 to 11, characterized in that: The thickness of the second intrinsic silicon layer is H8, and H8 satisfies: 0 nm<H8≤0.5 nm; and / or, The thickness of the sixth passivation layer is smaller than the thickness of the third passivation layer.

13. A method for preparing a solar cell, characterized in that: The preparation method comprises the following steps: A first intrinsic silicon layer is prepared on a light-receiving surface of a silicon substrate, a first passivation layer is prepared on the first intrinsic silicon layer, a second passivation layer is prepared on the first passivation layer using hydrogen and silane, and a third passivation layer is prepared on the second passivation layer using the hydrogen and silane to obtain a first composite passivation layer; wherein the flow ratio of the hydrogen and silane used to prepare the second passivation layer is A1, and the flow ratio of the hydrogen and silane used to prepare the third passivation layer is A2, and A1 and A2 satisfy the following conditions: 5:1≤A1≤10:1, 20:1≤A2≤50:1; preparing a first doping layer on the third passivation layer; preparing a first transparent conductive layer on the first doped layer; A first electrode is prepared on the first transparent conductive layer to obtain the solar cell.

14. The preparation method according to claim 13, characterized in that In the step of preparing the first intrinsic silicon layer on the light-receiving surface of the silicon substrate, the preparation parameters include: the process gas includes SiH4, the gas pressure is 0.6 Torr to 0.97 Torr, the ignition power is 800 W to 1200 W, the ignition time is 1 s to 2 s, and the SiH4 flow rate is 800 sccm to 1800 sccm; and / or, In the step of preparing a second passivation layer on the first passivation layer by using the hydrogen and silane, the process gases include SiH4 and H2, the gas pressure is 0.5 Torr to 0.57 Torr, the ignition power is 600 W to 800 W, the ignition time is 15 s to 25 s, the flow rate of SiH4 is 600 sccm to 1200 sccm, and the flow rate of H2 is 3000 sccm to 12000 sccm; and / or, In the step of preparing a third passivation layer on the second passivation layer by using the hydrogen and the silane, the preparation parameters include: the process gases include SiH4 and H2, the gas pressure is 0.5 Torr~0.57 Torr, the ignition power is 600 W~800 W, the ignition time is 10 s~15 s, the flow rate of SiH4 is 600 sccm~1200 sccm, and the flow rate of H2 is 12000 sccm~60000 sccm.

15. The preparation method according to claim 14, characterized in that The step of preparing a first passivation layer on the first intrinsic silicon layer includes: preparing a first passivation layer on the first intrinsic silicon layer using the hydrogen and the silane, wherein the flow ratio of the hydrogen and the silane in the first passivation layer is A3, the A3 is less than the A1, and the A3 satisfies: A3≤5:

1.

16. The preparation method according to claim 15, characterized in that Preparation parameters include: process gases include SiH4 and H2, gas pressure is 0.5 Torr~0.57 Torr, ignition power is 400 W~600 W, ignition time is 2 s~4 s, SiH4 flow rate is 200 sccm~600 sccm, and H2 flow rate is 200 sccm~3000 sccm.

17. The preparation method according to claim 13, characterized in that After the step of preparing the first composite passivation layer and before the step of preparing the first doping layer on the third passivation layer, the method for preparing a solar cell further includes: preparing a second intrinsic silicon layer on the backlight side of the silicon substrate, and preparing a fourth passivation layer on the surface of the second intrinsic silicon layer facing away from the silicon substrate using the hydrogen and silane to prepare a second composite passivation layer; wherein the flow ratio of the hydrogen and silane used to prepare the fourth passivation layer is A4, and A4 satisfies: 40:1≤A4≤70:

1.

18. The preparation method according to claim 17, characterized in that In the step of preparing the second intrinsic silicon layer on the backlight surface of the silicon substrate, the preparation parameters include: process gas includes SiH4, gas pressure is 0.7 Torr~0.97 Torr, ignition power is 800 W~1200 W, ignition time is 1 s~2 s, and SiH4 flow rate is 800 sccm~1800 sccm; and / or, In the step of preparing a fourth passivation layer on the second intrinsic silicon layer away from the silicon substrate using the hydrogen and the silane, the preparation parameters include: process gases include SiH4 and H2, gas pressure is 0.5 Torr~0.57 Torr, ignition power is 400 W~600 W, ignition time is 2 s~4 s, SiH4 flow rate is 200 sccm~600 sccm, and H2 flow rate is 8000 sccm~42000 sccm.

19. The preparation method according to claim 17, characterized in that After the step of preparing a fourth passivation layer on the surface of the second intrinsic silicon layer away from the silicon substrate using the hydrogen and the silane, and before the step of preparing a first doped layer on the third passivation layer, the method for preparing a solar cell further includes: sequentially preparing a fifth passivation layer and a sixth passivation layer on the surface of the fourth passivation layer away from the silicon substrate using the hydrogen and the silane, wherein the flow ratio of the hydrogen and the silane used to prepare the fifth passivation layer is A5, and the flow ratio of the hydrogen and the silane used to prepare the sixth passivation layer is A6, and A4, A5 and A6 show a downward trend, and A5 and A6 satisfy: 30:1≤A5≤60:1, 25:1≤A6≤55:

1.

20. The preparation method according to claim 19, characterized in that In the step of preparing the fifth passivation layer, the preparation parameters include: process gases including SiH4 and H2, gas pressure of 0.5 Torr to 0.57 Torr, ignition power of 600 W to 800 W, ignition time of 15 s to 25 s, SiH4 flow rate of 600 sccm to 1200 sccm, and H2 flow rate of 18000 sccm to 72000 sccm; and / or, In the step of preparing the sixth passivation layer, the preparation parameters include: the process gas includes SiH4 and H2, the gas pressure is 0.5 Torr~0.57 Torr, the ignition power is 800 W~1000 W, the ignition time is 5 s~10 s, the SiH4 flow rate is 600 sccm~1200 sccm, and the H2 flow rate is 15000 sccm~66000 sccm.

21. The preparation method according to claim 19 or 20, characterized in that: After the step of preparing the first doping layer on the third passivation layer and before the step of preparing the first transparent conductive layer on the first doping layer, the method for preparing a solar cell includes: preparing a second doping layer on the second composite passivation layer; After the step of preparing the first transparent conductive layer on the first doped layer and before the step of preparing the first electrode on the first transparent conductive layer, the method for preparing a solar cell includes: preparing a second transparent conductive layer on the second doped layer; After the step of preparing the first electrode on the first transparent conductive layer, the method for preparing the solar cell includes: preparing the second electrode on the second transparent conductive layer.

22. A photovoltaic module, characterized in that: include: The solar cell according to any one of claims 1 to 12, or the solar cell prepared by the preparation method according to any one of claims 13 to 21.

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