Topcon Solar Cells
By introducing PbSe quantum dots as semiconductor layer material in TOPCon solar cells, the problem of poor passivation effect of existing TOPCon solar cells is solved, and higher photoelectric conversion efficiency and fill factor are achieved.
Patent Information
- Application Number
- CN202421001509.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-09
- Publication Date
- 2025-04-04
- Estimated Expiration
- 2034-05-09
AI Technical Summary
The existing TOPCon solar cells have poor passivation effect and serious compound losses.
In the structure of TOPCon solar cells, PbSe quantum dots are introduced as the material of n-type and p-type semiconductor layers, and a passivation layer is formed by annealing to reduce carrier recombination, thereby improving the passivation effect.
By introducing PbSe quantum dots, carrier recombination is reduced, the passivation effect of TOPCon solar cells is significantly improved, and the photoelectric conversion efficiency and fill factor are improved.
Smart Images
Figure CN222721909U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to solar cell technology, and in particular to Topcon solar cells. Background Art
[0002] TOPCon cell (Tunnel Oxide Passivated Contact solar cell, TOPcon) refers to a tunnel oxide passivated contact solar cell. Currently, TOPCon cell technology in crystalline silicon solar cell technology, as the mainstream representative of passivated contact technology, has entered the large-scale mass production stage. The back passivation contact structure of a conventional TOPCon cell usually includes a tunnel oxide layer covering the back surface of an n-type silicon substrate, a doped polysilicon layer covering the tunnel oxide layer, a passivation layer covering the doped polysilicon layer, an anti-reflection layer covering the passivation layer, and an electrode disposed on the anti-reflection layer. During the preparation process, the electrode is sintered at high temperature to penetrate the anti-reflection layer and the passivation layer to form an ohmic contact with the doped polysilicon layer.
[0003] At present, the main passivation effect for the battery is provided by the passivation layer. For the TOPCon batteries currently in mass production, the composite loss is serious and the passivation effect needs to be improved. Utility Model Content
[0004] The embodiments of the present application provide a Topcon solar cell and a method for preparing the same, so as to solve the technical problems of poor passivation effect and severe recombination loss of the TOPCon cell.
[0005] In a first aspect, an embodiment of the present application provides a Topcon solar cell, wherein the Topcon solar cell comprises:
[0006] Silicon-based;
[0007] A tunneling oxide layer disposed on the back surface of the silicon substrate;
[0008] a doped polysilicon layer disposed on the tunnel oxide layer;
[0009] A first passivation layer disposed on the doped polysilicon layer;
[0010] an n-type semiconductor layer disposed on the first passivation layer;
[0011] A first anti-reflection layer is disposed on the n-type semiconductor layer;
[0012] a first electrode protruding from the surface of the first anti-reflection layer and embedded in the doped polysilicon layer,
[0013] Wherein, the material of the n-type semiconductor layer includes PbSe quantum dots.
[0014] In some embodiments of the present application, the Topcon solar cell further comprises:
[0015] A boron-doped oxide layer disposed on the front surface of the silicon substrate;
[0016] a second passivation layer disposed on the boron-doped oxide layer;
[0017] a p-type semiconductor layer disposed on the second passivation layer;
[0018] A second anti-reflection layer is disposed on the p-type semiconductor layer;
[0019] a second electrode protruding from the surface of the second anti-reflection layer and embedded in the boron-doped oxide layer,
[0020] Wherein, the material of the p-type semiconductor layer includes PbSe quantum dots.
[0021] In some embodiments of the present application, the material of the first passivation layer is aluminum oxide; and / or,
[0022] The material of the second passivation layer is aluminum oxide; and / or,
[0023] The material of the first anti-reflection layer is silicon nitride; and / or,
[0024] The material of the second anti-reflection layer is silicon nitride.
[0025] In some embodiments of the present application, the thickness of the tunnel oxide layer is 1 to 10 nm; and / or,
[0026] The thickness of the doped polysilicon layer is 10 to 150 nm; and / or,
[0027] The thickness of the first passivation layer is 5 to 20 nm; and / or,
[0028] The thickness of the n-type semiconductor layer is 200-400 nm; and / or,
[0029] The thickness of the first anti-reflection layer is 20-100 nm; and / or,
[0030] The thickness of the boron-doped oxide layer is 50 to 150 nm; and / or,
[0031] The thickness of the second passivation layer is 5 to 20 nm; and / or,
[0032] The thickness of the p-type semiconductor layer is 200-400 nm; and / or,
[0033] The thickness of the second anti-reflection layer is 20-100 nm.
[0034] In a second aspect, an embodiment of the present application provides a method for preparing a Topcon solar cell, the method for preparing a Topcon solar cell comprising the following steps:
[0035] Providing a silicon wafer, selecting one side of the silicon wafer as a front surface and the other side as a back surface, and performing a texturing process on the front surface;
[0036] Performing a high-temperature boron diffusion process on the silicon wafer to form a boron-doped oxide layer;
[0037] performing a laser propulsion process on the boron-doped oxide layer;
[0038] Removing the boron-doped oxide layer formed by expansion on the back surface of the silicon wafer;
[0039] Preparing a tunneling oxide layer on the back surface of the silicon wafer;
[0040] preparing a doped polysilicon layer on the tunnel oxide layer;
[0041] performing annealing treatment on the doped polysilicon layer;
[0042] Preparing a first passivation layer on the surface of the polysilicon layer, and preparing a second passivation layer on the surface of the boron-doped oxide layer;
[0043] Preparing an n-type semiconductor layer on the surface of the first passivation layer, and preparing a p-type semiconductor layer on the surface of the second passivation layer;
[0044] Prepare a first anti-reflection layer on the surface of the n-type semiconductor layer, and prepare a second anti-reflection layer on the p-type semiconductor layer;
[0045] Printing conductive paste on the surfaces of the first anti-reflection layer and the second anti-reflection layer, and sintering the conductive paste to form a first electrode and a second electrode respectively,
[0046] Wherein, the material of the n-type semiconductor layer includes PbSe quantum dots.
[0047] In some embodiments of the present application, the step of preparing a doped polysilicon layer on the tunnel oxide layer comprises the following steps:
[0048] depositing a polysilicon film on the tunnel oxide layer;
[0049] The polysilicon film is subjected to phosphorus doping treatment to obtain a doped polysilicon layer.
[0050] In some embodiments of the present application, the step of preparing an n-type semiconductor layer on the surface of the first passivation layer comprises the following steps:
[0051] Placing an n-type PbSe quantum dot solution on the surface of the first passivation layer to form an n-type PbSe quantum dot solution film;
[0052] The n-type PbSe quantum dot solution film is annealed to obtain the n-type semiconductor layer.
[0053] In some embodiments of the present application, the step of preparing a p-type semiconductor layer on the surface of the second passivation layer comprises the following steps:
[0054] Placing a p-type PbSe quantum dot solution on the surface of the second passivation layer to form a p-type PbSe quantum dot solution film;
[0055] The p-type PbSe quantum dot solution film is annealed to obtain the p-type semiconductor layer.
[0056] In some embodiments of the present application, the material of the first passivation layer is aluminum oxide; and / or,
[0057] The material of the second passivation layer is aluminum oxide; and / or,
[0058] The material of the first anti-reflection layer is silicon nitride; and / or,
[0059] The material of the second anti-reflection layer is silicon nitride.
[0060] In some embodiments of the present application, the thickness of the tunnel oxide layer is 1 to 2 nm; and / or,
[0061] The thickness of the doped polysilicon layer is 120-150 nm; and / or,
[0062] The thickness of the first passivation layer is 5 to 10 nm; and / or,
[0063] The thickness of the n-type semiconductor layer is 200-300 nm; and / or,
[0064] The thickness of the first anti-reflection layer is 75-85 nm; and / or,
[0065] The thickness of the boron-doped oxide layer is 100-120 nm; and / or,
[0066] The thickness of the second passivation layer is 5 to 10 nm; and / or,
[0067] The thickness of the p-type semiconductor layer is 200-300 nm; and / or,
[0068] The thickness of the second anti-reflection layer is 70-80 nm.
[0069] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:
[0070] The Topcon solar cell provided in the embodiment of the present application has an n-type semiconductor layer whose material includes PbSe quantum dots. The PbSe quantum dots can reduce carrier recombination and improve the passivation effect of the Topcon solar cell. BRIEF DESCRIPTION OF THE DRAWINGS
[0071] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.
[0072] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.
[0073] Figure 1 A schematic diagram of the structure of a Topcon solar cell provided in an embodiment of the present application. DETAILED DESCRIPTION
[0074] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.
[0075] Unless otherwise specified, the terms used herein should be understood as commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which this application belongs. In the event of a conflict, this specification takes precedence.
[0076] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.
[0077] Existing TOPCon batteries have technical problems such as poor passivation effect and severe composite loss.
[0078] The technical solution provided by the embodiments of the present application is to solve the above technical problems, and the overall idea is as follows:
[0079] In the first aspect, the present application embodiment provides a Topcon solar cell, please refer to Figure 1, the Topcon solar cell comprises:
[0080] Silicon-based 1;
[0081] A tunneling oxide layer 3 disposed on the back surface of the silicon substrate 1;
[0082] A doped polysilicon layer 4 is disposed on the tunnel oxide layer 3;
[0083] A first passivation layer 51 is disposed on the doped polysilicon layer 4;
[0084] An n-type semiconductor layer 9 disposed on the first passivation layer 51;
[0085] A first anti-reflection layer 61 is disposed on the n-type semiconductor layer 9;
[0086] A first electrode 71 protruding from the surface of the first anti-reflection layer 61 and embedded in the doped polysilicon layer 4,
[0087] The material of the n-type semiconductor layer 9 includes PbSe quantum dots.
[0088] Those skilled in the art will understand that the silicon substrate 1 is generally a silicon wafer, which generally does not distinguish between the front surface and the back surface when leaving the factory. In the process of manufacturing Topcon solar cells, one of the sides will be first subjected to a texturing treatment, and the side with the texturing surface will be used as the front surface, and the side without the texturing surface will be used as the back surface.
[0089] Those skilled in the art will appreciate that the tunneling oxide layer 3 is a conventional structure in the art. The function of the tunneling oxide layer 3 is to reduce the interface state density between the silicon wafer substrate and the doped polysilicon layer 4 by chemical passivation. The majority carrier concentration is much higher than the minority carrier concentration, which reduces the probability of electron-hole recombination while increasing the resistivity to form selective contact for majority carriers. In the tunneling oxide layer 3, electrons pass through the oxide layer from the metal surface to the metal surface on the other side. This phenomenon only occurs in very thin oxide layers, usually less than a few nanometers. In this case, the wavelength of the electrons is comparable to the thickness of the tunneling oxide layer 3, so the electrons can pass through the tunneling oxide layer 3. Preparing the tunneling oxide layer 3 is a conventional technical solution in the art. As an example, the tunneling oxide layer 3 can be prepared by methods such as PECVD, LPCVD, and the deposition atmosphere can include, for example, N2O and SiH4, oxygen, and the like.
[0090] Those skilled in the art will appreciate that preparing a passivation layer is a conventional technical solution in the art. The passivation layer, also known as an insulating layer, may be made of silicon nitride, aluminum oxide, titanium oxide, or silicon oxide, or any combination thereof. The passivation layer may be deposited by vapor deposition, sputtering, atomic deposition, or other methods.
[0091] Those skilled in the art will appreciate that the anti-reflection layer is a conventional structure in the art. The anti-reflection layer can be made of silicon nitride, aluminum oxide, titanium oxide or silicon oxide, or any combination thereof. The anti-reflection layer can be deposited by vapor deposition, sputtering, atomic deposition or other methods. As an example, the anti-reflection layer can be prepared by a PECVD method.
[0092] The material of the n-type semiconductor layer 9 includes PbSe quantum dots. During the annealing process, hydrogen ions in PbSe combine with dangling bonds in the n-type semiconductor layer 9 or its adjacent functional layer, reducing the density of trap states, providing a chemical passivation effect, and reducing the recombination of photogenerated carriers. It should be noted that PbSe quantum dots are usually prepared from dissolved precursors, so the PbSe quantum dot material usually contains a small amount of hydrogen ions.
[0093] The n-type semiconductor layer 9 provided in the present application is made of PbSe quantum dots, which can reduce carrier recombination and improve the passivation effect of the Topcon solar cell.
[0094] In some embodiments of the present application, the Topcon solar cell further comprises:
[0095] A boron-doped oxide layer 2 disposed on the front surface of the silicon substrate 1;
[0096] A second passivation layer 52 disposed on the boron-doped oxide layer 2;
[0097] A p-type semiconductor layer 8 disposed on the second passivation layer 52;
[0098] A second anti-reflection layer 62 disposed on the p-type semiconductor layer 8;
[0099] A second electrode 72 protruding from the surface of the second anti-reflection layer 62 and embedded in the boron-doped oxide layer 2,
[0100] The material of the p-type semiconductor layer 8 includes PbSe quantum dots.
[0101] The material of the p-type semiconductor layer 8 includes PbSe quantum dots. During the annealing process, hydrogen ions in the PbSe quantum dots combine with dangling bonds in the p-type semiconductor layer 8 or its adjacent functional layer to reduce the trap state density, provide a chemical passivation effect, and reduce the recombination of photogenerated carriers.
[0102] In addition, PbSe has high quantum efficiency under 1295nm wavelength illumination conditions. The addition of PbSe quantum dots can enhance the absorption capacity of Topcon solar cells for long-wave light.
[0103] It is easy to understand that the p-type semiconductor layer 8 includes PbSe quantum dots, which can not only reduce carrier recombination, but also increase the absorption capacity of the Topcon solar cell to light of different wavelengths, and ultimately improve the photoelectric efficiency of the Topcon solar cell.
[0104] In some embodiments of the present application, the material of the first passivation layer 51 is aluminum oxide; and / or,
[0105] The material of the second passivation layer 52 is aluminum oxide; and / or,
[0106] The material of the first anti-reflection layer 61 is silicon nitride; and / or,
[0107] The material of the second anti-reflection layer is silicon nitride.
[0108] In some embodiments of the present application, the thickness of the tunnel oxide layer 3 is 1-2 nm; and / or,
[0109] The thickness of the doped polysilicon layer 4 is 120-150 nm; and / or,
[0110] The thickness of the first passivation layer 51 is 5-10 nm; and / or,
[0111] The thickness of the n-type semiconductor layer 9 is 200-400 nm; and / or,
[0112] The thickness of the first anti-reflection layer 61 is 75-85 nm; and / or,
[0113] The thickness of the boron-doped oxide layer 2 is 100-120 nm; and / or,
[0114] The thickness of the second passivation layer 52 is 5-10 nm; and / or,
[0115] The thickness of the p-type semiconductor layer 8 is 200-400 nm; and / or,
[0116] The thickness of the second anti-reflection layer 62 is 70-80 nm.
[0117] In a second aspect, the present invention provides a method for preparing a Topcon solar cell. The Topcon solar cell structure prepared by the method is as follows: Figure 1 As shown, the method for preparing the Topcon solar cell comprises the following steps:
[0118] S01: providing a silicon wafer, selecting one side of the silicon wafer as a front surface and the other side as a back surface, and performing a texturing process on the front surface;
[0119] S02: performing a high-temperature boron diffusion process on the silicon wafer to form a boron-doped oxide layer 2;
[0120] S03: performing laser propulsion treatment on the boron-doped oxide layer 2;
[0121] S04: removing the boron-doped oxide layer 2 formed by the expansion on the back surface of the silicon wafer;
[0122] S05: preparing a tunneling oxide layer 3 on the back surface of the silicon wafer;
[0123] S06: preparing a doped polysilicon layer 4 on the tunneling oxide layer 3;
[0124] S07: performing annealing treatment on the doped polysilicon layer 4;
[0125] S08: preparing a first passivation layer 51 on the surface of the polysilicon layer, and preparing a second passivation layer 52 on the surface of the boron-doped oxide layer 2;
[0126] S09: preparing an n-type semiconductor layer 9 on the surface of the first passivation layer 51 , and preparing a p-type semiconductor layer 8 on the surface of the second passivation layer 52 ;
[0127] S10: preparing a first anti-reflection layer 61 on the surface of the n-type semiconductor layer 9, and preparing a second anti-reflection layer 62 on the p-type semiconductor layer 8;
[0128] S11: printing a conductive paste on the surface of the first anti-reflection layer 61 and the second anti-reflection layer 62, and sintering the conductive paste to form a first electrode 71 and a second electrode 72 respectively.
[0129] The material of the n-type semiconductor layer 9 includes PbSe quantum dots.
[0130] Those skilled in the art can understand that texturing is a conventional technical means in this field, which can form special morphologies on the surface of silicon wafers. For example, a pyramid-like morphology can be obtained by alkali texturing, and a wormhole-like morphology can be obtained by acid texturing. Texturing can improve the light trapping effect of silicon wafers. In the field of Topcon batteries, alkali texturing is generally used.
[0131] Those skilled in the art will appreciate that the high temperature boron diffusion is carried out in an oxygen atmosphere including at least one of BCl3 and BBr3. The high temperature boron diffusion causes a small number of boron atoms to be doped into the back surface of the silicon wafer, a process called wrap-around diffusion. The boron doped oxide layer 2 formed by wrap-around diffusion generally needs to be removed. The removal of the boron doped oxide layer 2 can be carried out by conventional methods in the art. As an example, the boron doped oxide layer 2 can be removed by hydrofluoric acid.
[0132] Those skilled in the art can understand that laser propulsion is a conventional technical means in this field, which refers to a technical means of using laser to process the doping layer to diffuse the doping atoms into the matrix.
[0133] Those skilled in the art will appreciate that it is a conventional technical means in the art to prepare the tunnel oxide layer 3. As an example, the tunnel oxide layer 3 can be prepared by PECVD, LPCVD and other methods, and the deposition atmosphere can include N2O, SiH4, oxygen and the like.
[0134] Those skilled in the art can understand that it is a conventional technical means in the art to prepare the doped polysilicon layer 4. As an example, the doped polysilicon layer 4 can be prepared by PECVD, LPCVD and other methods, and SiH4 can be selected as the deposition atmosphere.
[0135] Those skilled in the art will appreciate that preparing an anti-reflection layer is a conventional technical solution in the art. The anti-reflection layer can be made of silicon nitride, aluminum oxide, titanium oxide or silicon oxide, or any combination thereof. The anti-reflection layer can be deposited by vapor deposition, sputtering, atomic deposition or other methods. As an example, the anti-reflection layer can be prepared by a PECVD method.
[0136] In some embodiments of the present application, the step of preparing the doped polysilicon layer 4 on the tunneling oxide layer 3 comprises the following steps:
[0137] S061: depositing a polysilicon thin film on the tunnel oxide layer 3;
[0138] S062: performing phosphorus doping treatment on the polysilicon film to obtain a doped polysilicon layer 4.
[0139] In some embodiments, the phosphorus doping treatment method uses high temperature phosphorus diffusion. High temperature phosphorus diffusion is also accompanied by a wrap-around phenomenon, and the phosphorus doped layer that has been wrapped around the boron-doped oxide layer 2 needs to be removed.
[0140] In some embodiments of the present application, the n-type semiconductor layer 9 and the p-type semiconductor layer 8 are both prepared by spin coating of an n-type PbSe quantum dot precursor prepared by chemical hot injection and a p-type PbSe quantum dot precursor prepared by chemical hot injection.
[0141] In some embodiments of the present application, the material of the first passivation layer 51 is aluminum oxide; and / or,
[0142] The material of the second passivation layer 52 is aluminum oxide; and / or,
[0143] The material of the first anti-reflection layer 61 is silicon nitride; and / or,
[0144] The material of the second anti-reflection layer is silicon nitride.
[0145] In some embodiments of the present application, the thickness of the tunnel oxide layer 3 is 1-2 nm; and / or,
[0146] The thickness of the doped polysilicon layer 4 is 100-150 nm; and / or,
[0147] The thickness of the first passivation layer 51 is 5-10 nm; and / or,
[0148] The thickness of the n-type semiconductor layer 9 is 200-400 nm; and / or,
[0149] The thickness of the first anti-reflection layer 61 is 75-85 nm; and / or,
[0150] The thickness of the boron-doped oxide layer 2 is 100-120 nm; and / or,
[0151] The thickness of the second passivation layer 52 is 5-10 nm; and / or,
[0152] The thickness of the p-type semiconductor layer 8 is 200-400 nm; and / or,
[0153] The thickness of the second anti-reflection layer 62 is 70-80 nm.
[0154] The present application will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are intended only to illustrate the present application and are not intended to limit the scope of the present application. The experimental methods for which specific conditions are not specified in the following examples are usually measured according to industry standards. If there is no corresponding industry standard, then the conditions recommended by the manufacturer are followed.
[0155] Example 1
[0156] This embodiment provides a Topcon solar cell, including:
[0157] Silicon-based;
[0158] A tunneling oxide layer disposed on the back surface of the silicon substrate;
[0159] a doped polysilicon layer disposed on the tunnel oxide layer;
[0160] A first passivation layer disposed on the doped polysilicon layer;
[0161] an n-type semiconductor layer disposed on the first passivation layer;
[0162] A first anti-reflection layer is disposed on the n-type semiconductor layer;
[0163] A first electrode protruding from the surface of the first anti-reflection layer and embedded in the doped polysilicon layer;
[0164] A boron-doped oxide layer disposed on the front surface of the silicon substrate;
[0165] a second passivation layer disposed on the boron-doped oxide layer;
[0166] a p-type semiconductor layer disposed on the second passivation layer;
[0167] A second anti-reflection layer is disposed on the p-type semiconductor layer;
[0168] a second electrode protruding from the surface of the second anti-reflection layer and embedded in the boron-doped oxide layer,
[0169] Among them, the material of the p-type semiconductor layer includes PbSe quantum dots, the material of the n-type semiconductor layer includes PbSe quantum dots, the material of the first passivation layer is aluminum oxide, the material of the second passivation layer is aluminum oxide, the material of the first anti-reflection layer is silicon nitride, and the material of the second anti-reflection layer is silicon nitride.
[0170] The thickness of the tunneling oxide layer is 2nm, the thickness of the doped polysilicon layer is 100nm, the thickness of the first passivation layer is 5nm, the thickness of the n-type semiconductor layer is 200nm, the thickness of the first anti-reflection layer is 80nm, the thickness of the boron-doped oxide layer is 100nm, the thickness of the second passivation layer is 5nm, the thickness of the p-type semiconductor layer is 200nm, and the thickness of the second anti-reflection layer is 80nm.
[0171] The method for preparing the Topcon solar cell comprises the following steps:
[0172] Providing an n-type silicon wafer, selecting one side of the silicon wafer as a front surface and the other side as a back surface, and performing a texturing process on the front surface;
[0173] In a tubular diffusion furnace, the silicon wafer is subjected to a high-temperature boron diffusion treatment under BCl3 to form a boron-doped oxide layer;
[0174] performing a laser propulsion process on the boron-doped oxide layer;
[0175] Removing the boron-doped oxide layer formed by expansion on the back surface of the silicon wafer;
[0176] Placing a silicon wafer in an LPCVD reaction chamber, introducing O2, and preparing a tunneling oxide layer on the back surface of the silicon wafer;
[0177] Introducing SiH4 into the LPCVD reaction chamber to deposit a polysilicon film on the tunneling oxide layer;
[0178] The silicon wafer is transferred to a tubular diffusion furnace, and the polycrystalline silicon thin film is subjected to phosphorus doping treatment in a POCl3 atmosphere to obtain a doped polycrystalline silicon layer;
[0179] Washing away the phosphorus-doped layer that has spread around the boron-doped oxide layer with hydrofluoric acid;
[0180] performing annealing treatment on the doped polysilicon layer;
[0181] Depositing aluminum oxide on the surface of the polysilicon layer to prepare a first passivation layer, and depositing aluminum oxide on the surface of the boron-doped oxide layer to prepare a second passivation layer;
[0182] Spin coating an n-type PbSe quantum dot solution on the surface of the first passivation layer to form an n-type PbSe quantum dot solution film, and annealing the n-type silicon wafer and the functional layer prepared thereon at 285° C. to form an n-type semiconductor layer on the surface of the first passivation layer;
[0183] Spin coating a p-type PbSe quantum dot solution on the surface of the second passivation layer to form a p-type PbSe quantum dot solution film, and annealing the p-type silicon wafer and the functional layer prepared thereon at 285° C. to form a p-type semiconductor layer on the surface of the second passivation layer;
[0184] Depositing silicon nitride on the surface of the n-type semiconductor layer to prepare a first anti-reflection layer, and depositing silicon nitride on the surface of the p-type semiconductor layer to prepare a second anti-reflection layer;
[0185] Conductive paste is printed on the surfaces of the first anti-reflection layer and the second anti-reflection layer, and the conductive paste is sintered to form a first electrode and a second electrode respectively.
[0186] Example 2
[0187] This embodiment provides a Topcon solar cell, including:
[0188] Silicon-based;
[0189] A tunneling oxide layer disposed on the back surface of the silicon substrate;
[0190] a doped polysilicon layer disposed on the tunnel oxide layer;
[0191] A first passivation layer disposed on the doped polysilicon layer;
[0192] an n-type semiconductor layer disposed on the first passivation layer;
[0193] A first anti-reflection layer is disposed on the n-type semiconductor layer;
[0194] A first electrode protruding from the surface of the first anti-reflection layer and embedded in the doped polysilicon layer;
[0195] A boron-doped oxide layer disposed on the front surface of the silicon substrate;
[0196] a second passivation layer disposed on the boron-doped oxide layer;
[0197] a p-type semiconductor layer disposed on the second passivation layer;
[0198] A second anti-reflection layer is disposed on the p-type semiconductor layer;
[0199] a second electrode protruding from the surface of the second anti-reflection layer and embedded in the boron-doped oxide layer,
[0200] Among them, the material of the p-type semiconductor layer includes PbSe quantum dots, the material of the n-type semiconductor layer includes PbSe quantum dots, the material of the first passivation layer is aluminum oxide, the material of the second passivation layer is aluminum oxide, the material of the first anti-reflection layer is silicon nitride, and the material of the second anti-reflection layer is silicon nitride.
[0201] The thickness of the tunneling oxide layer is 2nm, the thickness of the doped polysilicon layer is 150nm, the thickness of the first passivation layer is 7nm, the thickness of the n-type semiconductor layer is 200nm, the thickness of the first anti-reflection layer is 80nm, the thickness of the boron-doped oxide layer is 100nm, the thickness of the second passivation layer is 5nm, the thickness of the p-type semiconductor layer is 400nm, and the thickness of the second anti-reflection layer is 80nm.
[0202] The method for preparing the Topcon solar cell comprises the following steps:
[0203] Providing an n-type silicon wafer, selecting one side of the silicon wafer as a front surface and the other side as a back surface, and performing a texturing process on the front surface;
[0204] In a tubular diffusion furnace, the silicon wafer is subjected to a high-temperature boron diffusion treatment under BCl3 to form a boron-doped oxide layer;
[0205] performing a laser propulsion process on the boron-doped oxide layer;
[0206] Removing the boron-doped oxide layer formed by expansion on the back surface of the silicon wafer;
[0207] Placing a silicon wafer in an LPCVD reaction chamber, introducing O2, and preparing a tunneling oxide layer on the back surface of the silicon wafer;
[0208] Introducing SiH4 into the LPCVD reaction chamber to deposit a polysilicon film on the tunneling oxide layer;
[0209] The silicon wafer is transferred to a tubular diffusion furnace, and the polycrystalline silicon thin film is subjected to phosphorus doping treatment in a POCl3 atmosphere to obtain a doped polycrystalline silicon layer;
[0210] Washing away the phosphorus-doped layer that has spread around the boron-doped oxide layer with hydrofluoric acid;
[0211] performing annealing treatment on the doped polysilicon layer;
[0212] Depositing aluminum oxide on the surface of the polysilicon layer to prepare a first passivation layer, and depositing aluminum oxide on the surface of the boron-doped oxide layer to prepare a second passivation layer;
[0213] Spin coating an n-type PbSe quantum dot solution on the surface of the first passivation layer to form an n-type PbSe quantum dot solution film, and annealing the n-type silicon wafer and the functional layer prepared thereon at 285° C. to form an n-type semiconductor layer on the surface of the first passivation layer;
[0214] Spin coating a p-type PbSe quantum dot solution on the surface of the second passivation layer to form a p-type PbSe quantum dot solution film, and annealing the p-type silicon wafer and the functional layer prepared thereon at 285° C. to form a p-type semiconductor layer on the surface of the second passivation layer;
[0215] Depositing silicon nitride on the surface of the n-type semiconductor layer to prepare a first anti-reflection layer, and depositing silicon nitride on the surface of the p-type semiconductor layer to prepare a second anti-reflection layer;
[0216] Conductive paste is printed on the surfaces of the first anti-reflection layer and the second anti-reflection layer, and the conductive paste is sintered to form a first electrode and a second electrode respectively.
[0217] Example 3
[0218] This embodiment provides a Topcon solar cell, including:
[0219] Silicon-based;
[0220] A tunneling oxide layer disposed on the back surface of the silicon substrate;
[0221] a doped polysilicon layer disposed on the tunnel oxide layer;
[0222] A first passivation layer disposed on the doped polysilicon layer;
[0223] an n-type semiconductor layer disposed on the first passivation layer;
[0224] A first anti-reflection layer is disposed on the n-type semiconductor layer;
[0225] A first electrode protruding from the surface of the first anti-reflection layer and embedded in the doped polysilicon layer;
[0226] A boron-doped oxide layer disposed on the front surface of the silicon substrate;
[0227] a second passivation layer disposed on the boron-doped oxide layer;
[0228] a p-type semiconductor layer disposed on the second passivation layer;
[0229] A second anti-reflection layer is disposed on the p-type semiconductor layer;
[0230] a second electrode protruding from the surface of the second anti-reflection layer and embedded in the boron-doped oxide layer,
[0231] Among them, the material of the p-type semiconductor layer includes PbSe quantum dots, the material of the n-type semiconductor layer includes PbSe quantum dots, the material of the first passivation layer is aluminum oxide, the material of the second passivation layer is aluminum oxide, the material of the first anti-reflection layer is silicon nitride, and the material of the second anti-reflection layer is silicon nitride.
[0232] The thickness of the tunneling oxide layer is 1nm, the thickness of the doped polysilicon layer is 100nm, the thickness of the first passivation layer is 10nm, the thickness of the n-type semiconductor layer is 300nm, the thickness of the first anti-reflection layer is 75nm, the thickness of the boron-doped oxide layer is 120nm, the thickness of the second passivation layer is 10nm, the thickness of the p-type semiconductor layer is 300nm, and the thickness of the second anti-reflection layer is 80nm.
[0233] The method for preparing the Topcon solar cell comprises the following steps:
[0234] Providing an n-type silicon wafer, selecting one side of the silicon wafer as a front surface and the other side as a back surface, and performing a texturing process on the front surface;
[0235] In a tubular diffusion furnace, the silicon wafer is subjected to a high-temperature boron diffusion treatment under BCl3 to form a boron-doped oxide layer;
[0236] performing a laser propulsion process on the boron-doped oxide layer;
[0237] Removing the boron-doped oxide layer formed by expansion on the back surface of the silicon wafer;
[0238] Placing a silicon wafer in an LPCVD reaction chamber, introducing O2, and preparing a tunneling oxide layer on the back surface of the silicon wafer;
[0239] Introducing SiH4 into the LPCVD reaction chamber to deposit a polysilicon film on the tunnel oxide layer;
[0240] The silicon wafer is transferred to a tubular diffusion furnace, and the polycrystalline silicon thin film is subjected to phosphorus doping treatment in a POCl3 atmosphere to obtain a doped polycrystalline silicon layer;
[0241] Washing away the phosphorus-doped layer that has spread around the boron-doped oxide layer with hydrofluoric acid;
[0242] performing annealing treatment on the doped polysilicon layer;
[0243] Depositing aluminum oxide on the surface of the polysilicon layer to prepare a first passivation layer, and depositing aluminum oxide on the surface of the boron-doped oxide layer to prepare a second passivation layer;
[0244] Spin coating an n-type PbSe quantum dot solution on the surface of the first passivation layer to form an n-type PbSe quantum dot solution film, and annealing the n-type silicon wafer and the functional layer prepared thereon at 285° C. to form an n-type semiconductor layer on the surface of the first passivation layer;
[0245] Spin coating a p-type PbSe quantum dot solution on the surface of the second passivation layer to form a p-type PbSe quantum dot solution film, and annealing the p-type silicon wafer and the functional layer prepared thereon at 284° C. to form a p-type semiconductor layer on the surface of the second passivation layer;
[0246] Depositing silicon nitride on the surface of the n-type semiconductor layer to prepare a first anti-reflection layer, and depositing silicon nitride on the surface of the p-type semiconductor layer to prepare a second anti-reflection layer;
[0247] Conductive paste is printed on the surfaces of the first anti-reflection layer and the second anti-reflection layer, and the conductive paste is sintered to form a first electrode and a second electrode respectively.
[0248] Comparative Example 1
[0249] The only difference between this comparative example and Example 1 is that in this comparative example, no n-type semiconductor layer and p-type semiconductor layer are prepared.
[0250] The details are as follows:
[0251] This comparative example provides a Topcon solar cell, comprising:
[0252] Silicon-based;
[0253] A tunneling oxide layer disposed on the back surface of the silicon substrate;
[0254] a doped polysilicon layer disposed on the tunnel oxide layer;
[0255] A first passivation layer disposed on the doped polysilicon layer;
[0256] a first anti-reflection layer disposed on the first passivation layer;
[0257] A first electrode protruding from the surface of the first anti-reflection layer and embedded in the doped polysilicon layer;
[0258] A boron-doped oxide layer disposed on the front surface of the silicon substrate;
[0259] a second passivation layer disposed on the boron-doped oxide layer;
[0260] a second anti-reflection layer disposed on the second passivation layer;
[0261] a second electrode protruding from the surface of the second anti-reflection layer and embedded in the boron-doped oxide layer,
[0262] The material of the first passivation layer is aluminum oxide, the material of the second passivation layer is aluminum oxide, the material of the first anti-reflection layer is silicon nitride, and the material of the second anti-reflection layer is silicon nitride.
[0263] The thickness of the tunneling oxide layer is 2nm, the thickness of the doped polysilicon layer is 100nm, the thickness of the first passivation layer is 5nm, the thickness of the first anti-reflection layer is 80nm, the thickness of the boron-doped oxide layer is 100nm, the thickness of the second passivation layer is 5nm, and the thickness of the second anti-reflection layer is 80nm.
[0264] The method for preparing the Topcon solar cell comprises the following steps:
[0265] Providing an n-type silicon wafer, selecting one side of the silicon wafer as a front surface and the other side as a back surface, and performing a texturing process on the front surface;
[0266] In a tubular diffusion furnace, the silicon wafer is subjected to a high-temperature boron diffusion treatment under BCl3 to form a boron-doped oxide layer;
[0267] performing a laser propulsion process on the boron-doped oxide layer;
[0268] Removing the boron-doped oxide layer formed by expansion on the back surface of the silicon wafer;
[0269] Placing a silicon wafer in an LPCVD reaction chamber, introducing O2, and preparing a tunneling oxide layer on the back surface of the silicon wafer;
[0270] Introducing SiH4 into the LPCVD reaction chamber to deposit a polysilicon film on the tunneling oxide layer;
[0271] The silicon wafer is transferred to a tubular diffusion furnace, and the polycrystalline silicon thin film is subjected to phosphorus doping treatment in a POCl3 atmosphere to obtain a doped polycrystalline silicon layer;
[0272] Washing away the phosphorus-doped layer that has spread around the boron-doped oxide layer with hydrofluoric acid;
[0273] performing annealing treatment on the doped polysilicon layer;
[0274] Depositing aluminum oxide on the surface of the polysilicon layer to prepare a first passivation layer, and depositing aluminum oxide on the surface of the boron-doped oxide layer to prepare a second passivation layer;
[0275] Depositing silicon nitride on the surface of the first passivation layer to prepare a first anti-reflection layer, and depositing silicon nitride on the surface of the second passivation layer to prepare a second anti-reflection layer;
[0276] Conductive paste is printed on the surfaces of the first anti-reflection layer and the second anti-reflection layer, and the conductive paste is sintered to form a first electrode and a second electrode respectively.
[0277] Related experiments and effect data:
[0278] The photoelectric conversion efficiency and FF (fill factor) of the Topcon solar cells in Examples 1 to 3 and the comparative example were tested. The results are shown in Table 1.
[0279] Example 1 Example 2 Example 3 Comparative Example Photoelectric conversion efficiency (%) 25.6 25.7 25.6 25.5 FF(%) 85.4 85.8 85.4 85.2
[0280] Table 1
[0281] Depend on Figure 1 It can be found that the photoelectric conversion efficiency and FF of Examples 1 to 3 are higher than those of the comparative example. This may be because the addition of PbSe quantum dots in Examples 1 to 3 can convert part of the long-wave light into current, thereby increasing the photoelectric conversion efficiency and FF of the Topcon solar cell.
[0282] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present application; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numerical values within the range. For example, the range description from 1 to 6 should be considered to have specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.
[0283] In the present application, in the absence of any contrary description, the directional words used, such as "upper" and "lower", are specifically the directions of the drawings in the accompanying drawings. In addition, in the description of the present application specification, the terms "including", "comprising", etc. refer to "including but not limited to". Moreover, the terms "including", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of further restrictions, the elements defined by the sentence "including..." do not exclude the existence of other identical elements in the process, method, article or equipment including the elements. In this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. In this article, "and / or" describes the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B, which can represent: A exists alone, A and B exist at the same time, and B exists alone. For the association relationship of more than three associated objects described by "and / or", it means that any one of these three associated objects can exist alone, or any at least two of them exist at the same time. For example, for A, and / or B, and / or C, it can be represented that any one of A, B, and C exists alone, or any two of them exist at the same time, or three of them exist at the same time. In this article, "at least one" refers to one or more, and "multiple" refers to two or more. "At least one", "the following at least one (individual)" or similar expressions refer to any combination of these items, including any combination of single (individual) or plural (individual). For example, "at least one (individual) of a, b, or c", or "at least one (individual) of a, b, and c", can all represent: a, b, c, ab (i.e. a and b), ac, bc, or abc, wherein a, b, and c can be single or multiple, respectively.
[0284] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.
Claims
1. A Topcon solar cell, characterized in that: The Topcon solar cell comprises: Silicon-based; A tunneling oxide layer disposed on the back surface of the silicon substrate; a doped polysilicon layer disposed on the tunnel oxide layer; A first passivation layer disposed on the doped polysilicon layer; An n-type PbSe quantum dot semiconductor layer disposed on the first passivation layer; A first anti-reflection layer is disposed on the n-type PbSe quantum dot semiconductor layer; a first electrode protruding from the surface of the first anti-reflection layer and embedded in the doped polysilicon layer, The material of the first passivation layer is aluminum oxide; the material of the first anti-reflection layer is silicon nitride.
2. The Topcon solar cell according to claim 1, characterized in that: The Topcon solar cell also includes: A boron-doped oxide layer disposed on the front surface of the silicon substrate; a second passivation layer disposed on the boron-doped oxide layer; A p-type PbSe quantum dot semiconductor layer disposed on the second passivation layer; A second anti-reflection layer is disposed on the p-type PbSe quantum dot semiconductor layer; a second electrode protruding from the surface of the second anti-reflection layer and embedded in the boron-doped oxide layer, The material of the second passivation layer is aluminum oxide, and the material of the second anti-reflection layer is silicon nitride.
3. The Topcon solar cell according to claim 2, characterized in that: The thickness of the tunnel oxide layer is 1-10 nm; and / or, The thickness of the doped polysilicon layer is 10-150 nm; and / or, The thickness of the first passivation layer is 5-20 nm; and / or, The thickness of the n-type PbSe quantum dot semiconductor layer is 200-400 nm; and / or, The thickness of the first anti-reflection layer is 20-100 nm; and / or, The thickness of the boron-doped oxide layer is 30-150 nm; and / or, The thickness of the second passivation layer is 5-20 nm; and / or, The thickness of the p-type PbSe quantum dot semiconductor layer is 200-400 nm; and / or, The thickness of the second anti-reflection layer is 20-100 nm.