SHJ solar cell structure

Abstract

The utility model belongs to the field of photovoltaic technology. The utility model provides an SHJ solar cell structure, which comprises a silicon substrate, a first passivation layer, a first conductive type doping layer and a first transparent conductive layer structure which are positioned on the front surface of the silicon substrate, and a second passivation layer, a second conductive type doping layer and a second transparent conductive layer structure which are positioned on the back surface of the silicon substrate, and the first transparent conductive layer structure and / or the second transparent conductive layer structure comprises an alkaline earth metal stannate film layer. Compared with an ITO film layer, an AZO film layer and a TTO film layer used in the prior art, on one hand, main metal elements of the alkaline-earth metal stannate film layer are alkaline-earth metal and tin instead of rare metal, the cost advantage is better achieved, on the other hand, the alkaline-earth metal stannate film layer has the extremely high migration rate which can reach 300 cm < 2 > / V.s or above, and when the preparation method is suitable, the film layer can be applied to the field of organic light emitting devices. When the alkaline earth metal stannate film layer is adopted to construct the transparent conducting layer structure in the SHJ battery, the performance of the battery in all aspects can be effectively improved.

Description

Technical Field

[0001] This utility model belongs to the field of photovoltaic technology and relates to an SHJ solar cell structure. Background Technology

[0002] Silicon heterojunction (SHJ) solar cells are a new hot topic in the photovoltaic field, with many advantages such as high open-circuit voltage, high conversion efficiency, and low temperature coefficient.

[0003] Currently, the structure of conventional silicon heterojunction solar cells is as follows: Figure 4 As shown, from top to bottom, the battery comprises a first electrode 8, a first transparent conductive layer 6, an n-type amorphous or microcrystalline silicon layer 4, a first intrinsic amorphous or microcrystalline silicon passivation layer 2, an n-type monocrystalline silicon wafer 1, a second intrinsic amorphous or microcrystalline silicon passivation layer 3, a p-type amorphous or microcrystalline silicon layer 5, a second transparent conductive layer 7, and a second electrode 9. The first electrode 8, the first transparent conductive layer 6, the n-type amorphous or microcrystalline silicon layer 4, the first intrinsic amorphous or microcrystalline silicon passivation layer 2, and the n-type monocrystalline silicon wafer 1 constitute the first surface (or front side) of the battery. The n-type monocrystalline silicon wafer 1, the second intrinsic amorphous or microcrystalline silicon passivation layer 3, the p-type amorphous or microcrystalline silicon layer 5, the second transparent conductive layer 7, and the second electrode 9 constitute the second surface (or back side) of the battery.

[0004] In the above structure, the first transparent conductive layer 6 and the second transparent conductive layer 7 have a significant impact on battery performance. In the prior art, the conventional first transparent conductive layer 6 and second transparent conductive layer 7 are both made of indium tin oxide (ITO) material, forming a TCO film (transparent conductive oxide film). Although its mobility is 20-80 cm⁻¹ 2 The / V·s ratio is relatively high, but since indium in indium-based materials is a rare metal, it is not conducive to further reducing battery costs. Existing technologies also use zinc oxide-based or tin oxide-based materials to form the film layer, such as aluminum-doped zinc oxide (AZO) and tantalum-doped tin oxide (TTO), but the mobility of both is difficult to reach 30 cm⁻¹. 2 The voltage level is / V·s and above, which seriously affects the conversion efficiency of the battery.

[0005] Therefore, it is still necessary to develop and utilize a low-cost TCO film layer to form new batteries or battery structures, thereby improving battery performance while maintaining cost advantages through optimization of the transparent conductive layer and its structure. Utility Model Content

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide an SHJ solar cell structure. In this SHJ solar cell structure, the transparent conductive layer structure located on one or both sides of the silicon substrate includes an alkaline earth metal stannate film. The alkaline earth metal stannate film combines the advantages of low cost and high mobility, effectively improving the performance of the SHJ cell.

[0007] To achieve the above object, the utility model discloses the following technical scheme:

[0008] A SHJ solar cell structure, including silicon substrate, the first passivation layer in the front of silicon substrate, first conductive type doped layer, first transparent conductive layer structure and the second passivation layer in the back of silicon substrate, second conductive type doped layer, second transparent conductive layer structure, the first transparent conductive layer structure and / or second transparent conductive layer structure includes alkaline earth metal stannate film layer.

[0009] The utility model uses alkaline earth metal stannate film layer as TCO film layer to build transparent conductive layer structure in SHJ battery.Compared with ITO film layer, AZO film layer and TTO film layer used in prior art, on the one hand, the main metal element of alkaline earth metal stannate film layer is alkaline earth metal and tin instead of rare metal, and it has cost advantage, on the other hand, alkaline earth metal stannate film layer has very high mobility, can reach 300cm 2 / V·s and above, when the preparation method is suitable, using alkaline earth metal stannate film layer to build transparent conductive layer structure in SHJ battery, can effectively improve the performance of battery in all aspects.

[0010] It should be noted that the utility model does not limit the preparation method of the alkaline earth metal stannate film layer, and the person skilled in the art can select according to the actual situation, for example, PVD (physical vapor deposition), PLD (laser pulse deposition) or RPD (reactive plasma deposition) and other technologies can be used, preferably using the preparation method that can make the film quality and uniformity of the film layer better.

[0011] It can be understood that according to the common sense in the art, the conductive type of the first conductive type doped layer and the second conductive type doped layer is opposite, the first conductive type is preferably n-type doping, and the second conductive type is preferably p-type doping.

[0012] The utility model does not limit the specific material and thickness of each layer in SHJ solar cell structure except transparent conductive layer structure, and the person skilled in the art should reasonably adjust according to design requirements and performance targets.

[0013] Exemplarily, the SHJ solar cell structure includes:

[0014] The silicon substrate is preferably an n-type monocrystalline silicon wafer, and the thickness is preferably 110-180 μm, for example, it can be 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm or 180 μm, etc.

[0015] A first passivation layer, preferably intrinsic amorphous silicon or microcrystalline silicon, preferably on the first surface (front side) of the silicon substrate, preferably with a thickness of 3-10 nm, for example 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm or 10 nm, etc.

[0016] A second passivation layer, preferably intrinsic amorphous silicon or microcrystalline silicon, preferably on the second surface (back side) of the silicon substrate, preferably with a thickness of 3-10 nm, for example 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm or 10 nm, etc.

[0017] A first conductive type doped layer, preferably n-type amorphous or microcrystalline silicon, preferably on the first passivation layer, preferably with a thickness of 10-30 nm, for example 10 nm, 12 nm, 14 nm, 16 nm, 18 nm, 20 nm, 22 nm, 24 nm, 26 nm, 28 nm or 30 nm, etc.

[0018] A second conductive type doped layer, preferably p-type amorphous or microcrystalline silicon, preferably on the second passivation layer, preferably with a thickness of 10-40 nm, for example 10 nm, 12 nm, 14 nm, 16 nm, 18 nm, 20 nm, 22 nm, 24 nm, 26 nm, 28 nm, 30 nm, 32 nm, 34 nm, 36 nm, 38 nm or 40 nm, etc.

[0019] A first transparent conductive layer structure, preferably on the first conductive type doped layer, preferably with a thickness of 70-80 nm, for example 70 nm, 71 nm, 72 nm, 73 nm, 74 nm, 75 nm, 76 nm, 77 nm, 78 nm, 79 nm or 80 nm, etc.

[0020] A second transparent conductive layer structure, preferably on the second conductive type doped layer, preferably with a thickness of 70-80 nm, for example 70 nm, 71 nm, 72 nm, 73 nm, 74 nm, 75 nm, 76 nm, 77 nm, 78 nm, 79 nm or 80 nm, etc.

[0021] A first electrode, preferably on the first transparent conductive layer structure, preferably a copper electrode or a silver electrode;

[0022] A second electrode, preferably on the second transparent conductive layer structure, preferably a copper electrode or a silver electrode;

[0023] Due to the limitation of the length and to avoid redundancy, the values of the thickness of each layer structure are not exhaustively listed, it can be understood that the actual thickness is not limited to the listed values, other values within the above numerical range are also applicable.

[0024] The following is the preferred technical scheme of the utility model, but not as the restriction of the technical scheme provided by the utility model, through the following technical scheme, the technical purpose and beneficial effect of the utility model can be better achieved.

[0025] As the preferred technical scheme of the utility model, the alkaline earth metal stannate film layer includes any one of calcium stannate film layer, barium stannate film layer or strontium stannate film layer.

[0026] The material of the alkaline earth metal stannate film layer includes X a SnO b Material, wherein X is the alkaline earth metal element of the second main group, when X is calcium, barium and strontium respectively, the formed film layer is the calcium stannate film layer, barium stannate film layer and strontium stannate film layer; and 0 < a ≤ 1, for example, it can be 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.75, 0.9, 0.95 or 1, etc.; b ≤ 3, for example, it can be 2.9, 2.91, 2.92, 2.93, 2.94, 2.95, 2.96, 2.97, 2.98, 2.99 or 3, etc., but not limited to the listed values, other values not listed in the above value range are also applicable.

[0027] It should be noted that the alkaline earth metal stannate film layer can also be a single-layer composite film layer composed of different X a SnO b Material as a component, or a multi-layer combined film layer composed of single-layer film layers composed of different X a SnO b Material.

[0028] Further, the alkaline earth metal stannate film layer can be an optimized and improved film layer, for example, element doping or reaching oxygen loss state. The element doping can use lanthanum and / or cobalt, at this time, X a SnO b Material is changed to X a M c SnO bThe material M includes lanthanum and / or cobalt; for example, when X is barium and M is lanthanum, the alkaline earth metal stannate film layer includes a lanthanum-doped barium stannate film layer; and 0≤c<1, for example, can be 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.75, 0.9, 0.95 or 1, c=0, that is, no doping metal element M is contained, but is not limited to the listed values, and other values not listed in the above value range are also applicable; the oxygen loss state can be controlled by slightly reducing the stoichiometric value of the actual oxygen element compared with the value of oxygen in the stoichiometric ratio (standard stoichiometric ratio) of the chemical formula, that is, b<3, and the suitable oxygen loss state can effectively improve the conductivity of the alkaline earth metal stannate film layer.

[0029] As a preferred technical solution of the present application, the first transparent conductive layer structure and / or the second transparent conductive layer structure comprises at least two layers of TCO film layers, wherein the TCO film layer closest to the silicon substrate comprises any one of an ITO film layer, an AZO film layer or a TTO film layer.

[0030] As a preferred technical solution of the present application, the first transparent conductive layer structure and / or the second transparent conductive layer structure comprises at least three layers of TCO film layers, wherein the TCO film layer farthest from the silicon substrate comprises any one of an ITO film layer, an AZO film layer or a TTO film layer.

[0031] The present application finds that when the alkaline earth metal stannate film layer directly contacts the first conductive type doped layer (such as a conventional n-type amorphous silicon or microcrystalline silicon layer) or the second conductive type doped layer (such as a conventional p-type amorphous silicon or microcrystalline silicon layer) in the SHJ cell, contact problems are easily caused. Therefore, the transparent conductive layer structure is preferably divided into at least two layers, ITO and TTO film layers are used as contact layers to contact the amorphous silicon or microcrystalline silicon layer to improve the contact condition, and the alkaline earth metal stannate film layer is prepared on the formed contact layer to play the advantages of the alkaline earth metal stannate film layer, improve the mobility and enhance the performance of the cell.

[0032] Further, there are certain contact problems between the alkaline earth metal stannate film layer and the electrode (silver electrode or copper electrode). For example, in the process of electroplating the electrode, the electroplating solution and the film removal solution can corrode the alkaline earth metal stannate film layer, affecting the efficiency of the solar cell. Therefore, the transparent conductive layer structure is further preferably divided into at least three layers, the first layer is the above-mentioned contact layer, the middle layer is the alkaline earth metal stannate film layer, and the outermost layer is a TTO film layer, TTO exhibits stronger corrosion resistance in the electroplating process, so that it serves as a protective layer, further improving the stability of the transparent conductive layer structure.

[0033] As the preferred technical scheme of the utility model, the TCO film layer closest to the silicon substrate accounts for 2% to 25% of the total thickness of the transparent conductive layer structure, for example, 2%, 5%, 7%, 9%, 11%, 13%, 15%, 17%, 19%, 21%, 23% or 25%, etc., but is not limited to the listed values, and other values not listed within the above numerical range are also applicable.

[0034] As the preferred technical scheme of the utility model, the TCO film layer farthest from the silicon substrate accounts for 2% to 25% of the total thickness of the transparent conductive layer structure, for example, 2%, 5%, 7%, 9%, 11%, 13%, 15%, 17%, 19%, 21%, 23% or 25%, etc., but is not limited to the listed values, and other values not listed within the above numerical range are also applicable.

[0035] As the preferred technical scheme of the utility model, the total thickness of the alkaline earth metal stannate film layer accounts for 50% or more of the total thickness of the transparent conductive layer structure, for example, 50%, 54%, 58%, 62%, 66%, 70%, 74%, 78%, 82%, 86%, 90%, 92%, 96% or 98%, etc., but is not limited to the listed values, and other values not listed within the above numerical range are also applicable.

[0036] When the transparent conductive layer structure is divided into at least two TCO film layers, in order to ensure that the alkaline earth metal stannate film layer plays its due role, therefore, the thickness of the alkaline earth metal stannate film layer, the thickness and thickness ratio of the above contact layer and the above protective layer need to be limited, so that the contact layer, the protective layer and the alkaline earth metal stannate film layer mutually match to play their respective advantages and roles.

[0037] As the preferred technical scheme of the utility model, the first conductive type doped layer and / or the second conductive type doped layer are set as oxygen-doped microcrystalline silicon layers with the corresponding conductive type.

[0038] As the preferred technical scheme of the utility model, a first buffer layer is arranged between the first conductive type doped layer and the first transparent conductive layer structure, and the first buffer layer comprises an oxygen-doped microcrystalline silicon layer with the first conductive type.

[0039] As the preferred technical scheme of the utility model, a second buffer layer is arranged between the second conductive type doped layer and the second transparent conductive layer structure, and the second buffer layer comprises an oxygen-doped microcrystalline silicon layer with the second conductive type.

[0040] In order to improve the contact problem of the TCO film layer and the first conductive type doped layer and the second conductive type doped layer, or when the transparent conductive film layer does not adopt the scheme of being divided into at least two layers to set the contact layer and only has the alkaline earth metal stannate film layer, another way to improve the contact problem is provided, that is, the first conductive type doped layer and the second conductive type doped layer in direct contact with the TCO film layer, especially the alkaline earth metal stannate film layer, are set as an oxygen-doped microcrystalline silicon layer, or a layer of oxygen-doped microcrystalline silicon is added as a buffer layer between the first conductive type doped layer and the second conductive type doped layer and the TCO film layer in contact, so that the contact condition can be further improved, and the battery performance is improved.

[0041] Compared with the prior art, the utility model has the beneficial effects that:

[0042] (1) The utility model uses the alkaline earth metal stannate film layer as the TCO film layer to construct the transparent conductive layer structure in the SHJ battery, which can have the advantages of low cost and high mobility at the same time, and effectively improve the performance of the SHJ battery.

[0043] (2) The utility model sets the transparent conductive layer structure as a structure of two layers or more, sets the TCO film layer closest to the silicon substrate as a contact layer, and / or sets the TCO film layer farthest from the silicon substrate as a protective layer, and sets the contact layer and the protective layer as ITO, TTO and the like, which can effectively improve the contact problem, and the remaining alkaline earth metal stannate film layer can effectively improve the battery performance by using the high mobility advantage.

[0044] (3) The utility model sets the layer in contact with the TCO film layer closest to the silicon substrate as an n-type microcrystalline silicon layer or a p-type microcrystalline silicon layer, which further optimizes the contact condition and improves the battery performance. BRIEF DESCRIPTION OF DRAWINGS

[0045] Figure 1 It is a structure schematic view of the SHJ battery obtained in example 1.

[0046] Figure 2 It is a structure schematic view of the SHJ battery obtained in example 6.

[0047] Figure 3 It is a structure schematic view of the SHJ battery obtained in example 8.

[0048] Figures 1-3In the figure: 101-n type monocrystalline silicon wafer, 102-first intrinsic amorphous silicon passivation layer, 103-second intrinsic amorphous silicon passivation layer, 104-n type microcrystalline silicon layer, 105-p type microcrystalline silicon layer, 106-first transparent conductive layer structure, 107-second transparent conductive layer structure, 108-first electrode, 109-second electrode, 111-first TCO film layer, 112-second TCO film layer, 113-third TCO film layer, 114-fourth TCO film layer, 115-fifth TCO film layer, 116-sixth TCO film layer, 121-oxygen-doped n-type microcrystalline silicon buffer layer, 122-oxygen-doped p-type microcrystalline silicon buffer layer;

[0049] Figure 4 is a structure schematic diagram of a conventional SHJ cell in the prior art;

[0050] Figure 4 In the figure: 1-n type monocrystalline silicon wafer, 2-first intrinsic amorphous or microcrystalline silicon passivation layer, 3-second intrinsic amorphous or microcrystalline silicon passivation layer, 4-n type amorphous or microcrystalline silicon layer, 5-p type amorphous or microcrystalline silicon layer, 6-first transparent conductive layer, 7-second transparent conductive layer, 8-first electrode, 9-second electrode. DETAILED DESCRIPTION

[0051] In order to make the technical scheme, purpose and advantages of the present application clearer, the following will further describe the present application in detail with specific examples and in conjunction with the drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application.

[0052] In the description of the present application, it should be pointed out that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore it cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0053] In the description of the utility model, it is necessary to explain that, unless there is definite stipulation and limitation, the term "mount", "link", "connect" should do broad sense understanding, for example, can be fixed connection, also can be detachable connection, or integrally connect, can be mechanical connection, also can be electrical connection, can be direct connection, also can through the indirect connection of intermediate medium, can be the intercommunication of two elements. For the field of electricity and communication, can be wired connection, also can be wireless connection. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to specific circumstances.

[0054] The technical scheme of the utility model is further illustrated below by specific embodiments in conjunction with the drawings.

[0055] Embodiment 1

[0056] The embodiment provides a SHJ battery, and a structural schematic diagram of the SHJ battery is as shown in the figure: Figure 1

[0057] The SHJ battery sequentially comprises a first electrode 108, a first transparent conductive layer structure 106 (front side) with a thickness of 80nm, an n-type microcrystalline silicon layer 104 with a thickness of 15nm, a first intrinsic amorphous silicon passivation layer 102 with a thickness of 10nm, an n-type monocrystalline silicon wafer 101 with a thickness of 160μm, a second intrinsic amorphous silicon passivation layer 103 with a thickness of 10nm, a p-type microcrystalline silicon layer 105 with a thickness of 15nm, a second transparent conductive layer structure 107 (back side) with a thickness of 80nm and a second electrode 109 from top to bottom, wherein the first transparent conductive layer structure 106 is located on the first surface (front side), and the second transparent conductive layer structure 107 is located on the second surface (back side);

[0058] The first transparent conductive layer structure 106 and the second transparent conductive layer structure 107 are both a strontium stannate film layer, that is, a SrSnO3 film layer.

[0059] Embodiment 2

[0060] The embodiment provides a SHJ battery, and the strontium stannate film layer in the SHJ battery is in oxygen loss state, that is, the first transparent conductive layer structure 106 and the second transparent conductive layer structure 107 are both a strontium stannate film layer in oxygen loss state, that is, a SrSnO 2.95 Film layer, except the above, other conditions are completely same with embodiment 1.

[0061] Embodiment 3

[0062] The embodiment provides a SHJ battery, and the strontium stannate film layer in the SHJ battery is a film layer doped with lanthanum element, that is, the first transparent conductive layer structure 106 and the second transparent conductive layer structure 107 are both a strontium stannate film layer doped with lanthanum, that is, a Sr​0.9 La 0.1 SnO3 film layer, and other conditions are the same as Example 1.

[0063] Example 4

[0064] In this example, the first and second transparent conductive layer structures 106 and 107 in the SHJ cell are replaced by a layer of barium stannate film, i.e. BaSnO3 film, and other conditions are the same as Example 1.

[0065] Example 5

[0066] In this example, the first and second transparent conductive layer structures 106 and 107 in the SHJ cell are replaced by a layer of calcium stannate film, i.e. CaSnO3 film, and other conditions are the same as Example 1.

[0067] Example 6

[0068] In this example, the SHJ cell is provided, and a structure diagram thereof is shown in Figure 2 .

[0069] The first transparent conductive layer structure 106 (front side) of the SHJ cell includes, from bottom to top, a first TCO film layer 111 with a thickness of 10 nm, a second TCO film layer 112 with a thickness of 60 nm, and a third TCO film layer 113 with a thickness of 10 nm; the second transparent conductive layer structure 107 (back side) includes, from top to bottom, a fourth TCO film layer 114 with a thickness of 10 nm, a fifth TCO film layer 115 with a thickness of 60 nm, and a sixth TCO film layer 116 with a thickness of 10 nm; the first, third, fourth, and sixth TCO film layers 111, 113, 114, and 116 are ITO film layers, and the second and fifth TCO film layers 112 and 115 are SrSnO 2.95 film layers as in Example 2, and other conditions are the same as Example 2.

[0070] Example 7

[0071] In this example, the first and fourth TCO film layers 111 and 114 of the SHJ cell are ITO film layers, the second and fifth TCO film layers 112 and 115 are SrSnO 2.95 film layers as in Example 2, the third and sixth TCO film layers 113 and 116 are TTO film layers, and other conditions are the same as Example 2.

[0072] Example 8

[0073] This embodiment provides an SHJ battery, the structural schematic diagram of which is shown below. Figure 3 As shown, the SHJ battery contains an oxygen-doped n-type microcrystalline silicon buffer layer 121 and an oxygen-doped p-type microcrystalline silicon buffer layer 122. That is, an additional oxygen-doped n-type microcrystalline silicon buffer layer 121 with a thickness of 5 nm is provided between the first transparent conductive layer structure 106 and the n-type microcrystalline silicon layer 104, while the thickness of the n-type microcrystalline silicon layer 104 is adjusted from 15 nm to 10 nm; at the same time, an additional oxygen-doped p-type microcrystalline silicon buffer layer 122 with a thickness of 5 nm is provided between the second transparent conductive layer structure 107 and the p-type microcrystalline silicon layer 105, while the thickness of the p-type microcrystalline silicon layer 105 is adjusted from 15 nm to 10 nm. Except for the above, the other conditions are exactly the same as in Example 1.

[0074] Example 9

[0075] This embodiment provides an SHJ battery:

[0076] The SHJ battery, from top to bottom, includes a first electrode 108, a first transparent conductive layer structure 106 (front side) with a thickness of 80 nm, an oxygen-doped n-type microcrystalline silicon buffer layer 121 with a thickness of 5 nm, an n-type microcrystalline silicon layer 104 with a thickness of 10 nm, a first intrinsic amorphous silicon passivation layer 102 with a thickness of 10 nm, an n-type single crystal silicon wafer 101 with a thickness of 160 μm, a second intrinsic amorphous silicon passivation layer 103 with a thickness of 10 nm, a p-type microcrystalline silicon layer 105 with a thickness of 10 nm, an oxygen-doped p-type microcrystalline silicon buffer layer 122 with a thickness of 5 nm, a second transparent conductive layer structure 107 (back side) with a thickness of 80 nm, and a second electrode 109; wherein, the first transparent conductive layer structure 106 is located on the first surface (front side), and the second transparent conductive layer structure 107 is located on the second surface (back side).

[0077] The first transparent conductive layer structure 106 (front side) of the SHJ battery comprises, from bottom to top, a first TCO film layer 111 with a thickness of 10 nm, a second TCO film layer 112 with a thickness of 60 nm, and a third TCO film layer 113 with a thickness of 10 nm; the second conductive transparent layer structure 107 (back side) comprises, from top to bottom, a fourth TCO film layer 114 with a thickness of 10 nm, a fifth TCO film layer 115 with a thickness of 60 nm, and a sixth TCO film layer 116 with a thickness of 10 nm; the first TCO film layer 111 and the fourth TCO film layer 114 are ITO films, the third TCO film layer 113 and the sixth TCO film layer 116 are both TTO films, and the second TCO film layer 112 and the fifth TCO film layer 115 are both oxygen-degraded lanthanum-doped strontium stannate films, i.e., Sr 0.9 La 0.1 SnO2.95 Membrane.

[0078] Comparative Example 1

[0079] This comparative example provides an SHJ battery in which the first transparent conductive layer structure 106 and the second transparent conductive layer structure 107 are both replaced with an ITO film layer. Except for the above, the other conditions are exactly the same as in Example 1.

[0080] Comparative Example 2

[0081] This comparative example provides an SHJ battery in which the first transparent conductive layer structure 106 and the second transparent conductive layer structure 107 are both replaced with a TTO film layer. Except for the above, the other conditions are exactly the same as in Example 1.

[0082] Comparative Example 3

[0083] This comparative example provides an SHJ battery in which the first transparent conductive layer structure 106 and the second transparent conductive layer structure 107 are both replaced with an AZO film layer. Except for the above, the other conditions are exactly the same as in Example 1.

[0084] Comparative Example 4

[0085] This comparative example provides an SHJ battery, wherein the first TCO film layer 111 and the fourth TCO film layer 114 are ITO film layers, the third TCO film layer 113 and the sixth TCO film layer 116 are TTO film layers, and the second TCO film layer 112 and the fifth TCO film layer 115 are AZO film layers. Except for the above, the other conditions are exactly the same as those in Example 7.

[0086] In the above embodiments and comparative examples, the ITO, TTO, and AZO films were all fabricated using PVD (Polyvinyl Dioxide) with magnetron sputtering technology; the alkaline earth metal stannate films (including those undergoing doping and reaching an oxygen-depleted state) were all prepared using RPD (Reverse Polymerization), with hydrogen and water vapor used to optimize film quality and uniformity. In Examples 8 and 9, both the oxygen-doped n-type and p-type microcrystalline silicon buffer layers used nitrous oxide as the oxygen source for oxygen doping.

[0087] The SHJ batteries obtained in Examples 1-9 and Comparative Examples 1-4 were tested. Based on the performance data of the battery in Comparative Example 1, the battery performance of Comparative Example 1 was: open circuit voltage = 749.46mV, short circuit current = 11.05A, fill factor = 85.48%, conversion efficiency = 25.83%. The improvement effect (improvement rate) of each performance was calculated, and the results are shown in Table 1.

[0088] Table 1

[0089] Lift rate Open circuit voltage (Voc) Short circuit current (Isc) Fill factor (FF) Conversion efficiency (Eff) Example 1 0.05％ 0.07％ 0.08％ 0.20％ Example 2 0.06％ 0.07％ 0.09％ 0.22％ Example 3 0.06％ 0.09％ 0.11％ 0.26％ Example 4 0.05％ 0.08％ 0.07％ 0.20％ Example 5 0.04％ 0.08％ 0.08％ 0.20％ Example 6 0.13％ 0.14％ 0.11％ 0.38％ Example 7 0.10％ 0.16％ 0.10％ 0.36％ Example 8 0.06％ 0.08％ 0.09％ 0.23％ Example 9 0.11％ 0.16％ 0.14％ 0.41％ Comparative Example 2 -0.50％ -1.10％ -1.30％ -2.87％ Comparative Example 3 -0.40％ -0.40％ -0.70％ -1.49％ Comparative Example 4 -0.02％ -0.02％ -0.01％ -0.05％

[0090] From the above, it can be seen that:

[0091] Compared with Comparative Examples 1-3, the utility model uses the alkaline earth metal stannate film layer to replace the traditional ITO, TTO and AZO film layer to construct the transparent conductive layer, which is conducive to the high mobility advantage of the alkaline earth metal stannate film layer, and effectively improves the battery performance; and Comparative Example 4 uses ITO, TTO and AZO stacked film to construct the transparent conductive layer, which lacks the alkaline earth metal stannate film layer, and the battery performance is not obviously improved.

[0092] In Example 2, the alkaline earth metal stannate film layer is changed to an oxygen loss state, which can greatly improve the conductivity and improve the battery performance; in Example 3, the alkaline earth metal stannate film layer is doped with lanthanum, which can also optimize the film layer to a certain extent and improve the battery performance.

[0093] In Examples 4 and 5, the alkaline earth metal stannate film layer used is barium stannate film layer and calcium stannate film layer, and the battery performance of the two is equivalent to that of the strontium stannate film layer in Example 1.

[0094] In Examples 6 and 7, the transparent conductive layer structure is further subdivided to increase the contact layer and the protective layer, which is conducive to improving the contact problem and ensuring the alkaline earth metal stannate film layer to play a role, thereby further improving the battery performance.

[0095] In Example 8, the buffer layer is set to contact the transparent conductive layer structure, which can greatly improve the contact problem of the alkaline earth metal stannate film layer directly with the doped amorphous or microcrystalline silicon, thereby effectively improving the battery performance.

[0096] The results of Example 9 show that by using the optimized and improved alkaline earth metal stannate film layer to construct the transparent conductive layer structure, the contact problem is improved by stacking multiple TCO film layers, and the n-type or p-type microcrystalline silicon buffer layer is added, and the battery efficiency is maximally improved.

[0097] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited to this, and those skilled in the art should understand that any changes or replacements within the technical scope disclosed by the utility model can be easily thought of by those skilled in the art, and all fall within the protection scope and disclosure scope of the utility model.

Claims

1. A SHJ solar cell structure, comprising a silicon substrate, a first passivation layer, a first conductivity type doped layer, and a first transparent conductive layer structure located on the front side of the silicon substrate, and a second passivation layer, a second conductivity type doped layer, and a second transparent conductive layer structure located on the back side of the silicon substrate, characterized in that... The first transparent conductive layer structure and / or the second transparent conductive layer structure include an alkaline earth metal stannate film layer.

2. The SHJ solar cell structure according to claim 1, characterized in that, The alkaline earth metal stannate film includes any one of calcium stannate film, barium stannate film, or strontium stannate film.

3. The SHJ solar cell structure according to claim 1 or 2, characterized in that, The first transparent conductive layer structure and / or the second transparent conductive layer structure include at least two TCO film layers, wherein the TCO film layer closest to the silicon substrate includes any one of an ITO film layer, an AZO film layer, or a TTO film layer.

4. The SHJ solar cell structure according to claim 3, characterized in that, The first transparent conductive layer structure and / or the second transparent conductive layer structure include at least three TCO film layers, wherein the TCO film layer furthest from the silicon substrate includes any one of an ITO film layer, an AZO film layer, or a TTO film layer.

5. The SHJ solar cell structure according to claim 3, characterized in that, The TCO film layer closest to the silicon substrate accounts for 2% to 25% of the total thickness of the transparent conductive layer structure.

6. The SHJ solar cell structure according to claim 4, characterized in that, The TCO film layers furthest from the silicon substrate each account for 2% to 25% of the total thickness of the transparent conductive layer structure in which they are located.

7. The SHJ solar cell structure according to claim 3, characterized in that, The total thickness of the alkaline earth metal stannate film layer accounts for 50% or more of the total thickness of the transparent conductive layer structure.

8. The SHJ solar cell structure according to claim 1 or 2, characterized in that, The first conductivity type doped layer and / or the second conductivity type doped layer are configured as oxygen-doped microcrystalline silicon layers having the corresponding conductivity type.

9. The SHJ solar cell structure according to claim 1 or 2, characterized in that, A first buffer layer is disposed between a first conductivity type doped layer and a first transparent conductive layer structure, the first buffer layer comprising an oxygen-doped microcrystalline silicon layer having a first conductivity type.

10. The SHJ solar cell structure according to claim 1 or 2, characterized in that, A second buffer layer is disposed between the second conductivity type doped layer and the second transparent conductive layer structure, the second buffer layer comprising an oxygen-doped microcrystalline silicon layer having a second conductivity type.

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