CN114628539A - Texturing method for diamond wire-cut polycrystalline silicon wafer, textured silicon wafer and solar cell - Google Patents
Texturing method for diamond wire-cut polycrystalline silicon wafer, textured silicon wafer and solar cell Download PDFInfo
- Publication number
- CN114628539A CN114628539A CN202011436401.3A CN202011436401A CN114628539A CN 114628539 A CN114628539 A CN 114628539A CN 202011436401 A CN202011436401 A CN 202011436401A CN 114628539 A CN114628539 A CN 114628539A
- Authority
- CN
- China
- Prior art keywords
- silicon wafer
- texturing
- diamond wire
- polycrystalline silicon
- acid
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 title claims abstract description 75
- 229910052710 silicon Inorganic materials 0.000 title claims abstract description 75
- 239000010703 silicon Substances 0.000 title claims abstract description 75
- 229910021420 polycrystalline silicon Inorganic materials 0.000 title claims abstract description 59
- 229910003460 diamond Inorganic materials 0.000 title claims abstract description 58
- 239000010432 diamond Substances 0.000 title claims abstract description 58
- 238000000034 method Methods 0.000 title claims abstract description 46
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 43
- 239000002253 acid Substances 0.000 claims abstract description 41
- 238000005520 cutting process Methods 0.000 claims abstract description 25
- 239000000377 silicon dioxide Substances 0.000 claims abstract description 25
- 238000004140 cleaning Methods 0.000 claims abstract description 21
- 235000012239 silicon dioxide Nutrition 0.000 claims abstract description 17
- 238000011282 treatment Methods 0.000 claims description 35
- 239000003513 alkali Substances 0.000 claims description 25
- 238000005498 polishing Methods 0.000 claims description 20
- 230000003647 oxidation Effects 0.000 claims description 18
- 238000007254 oxidation reaction Methods 0.000 claims description 18
- 239000000243 solution Substances 0.000 claims description 17
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 claims description 16
- 239000001301 oxygen Substances 0.000 claims description 15
- 229910052760 oxygen Inorganic materials 0.000 claims description 15
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 13
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 12
- 238000009792 diffusion process Methods 0.000 claims description 11
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 claims description 10
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 8
- 239000011259 mixed solution Substances 0.000 claims description 8
- 238000007639 printing Methods 0.000 claims description 8
- 238000005245 sintering Methods 0.000 claims description 7
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims description 6
- 229910017604 nitric acid Inorganic materials 0.000 claims description 6
- 230000008021 deposition Effects 0.000 claims description 5
- 239000007864 aqueous solution Substances 0.000 claims description 4
- HIVGXUNKSAJJDN-UHFFFAOYSA-N [Si].[P] Chemical compound [Si].[P] HIVGXUNKSAJJDN-UHFFFAOYSA-N 0.000 claims description 3
- 239000011521 glass Substances 0.000 claims description 3
- 238000002310 reflectometry Methods 0.000 abstract description 18
- 235000012431 wafers Nutrition 0.000 description 111
- 230000000052 comparative effect Effects 0.000 description 10
- 238000005406 washing Methods 0.000 description 9
- 238000006243 chemical reaction Methods 0.000 description 7
- 229910052681 coesite Inorganic materials 0.000 description 7
- 229910052906 cristobalite Inorganic materials 0.000 description 7
- 229910052682 stishovite Inorganic materials 0.000 description 7
- 229910052905 tridymite Inorganic materials 0.000 description 7
- 229910004205 SiNX Inorganic materials 0.000 description 6
- 238000005516 engineering process Methods 0.000 description 6
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 4
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 4
- 238000000151 deposition Methods 0.000 description 4
- 230000005684 electric field Effects 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 229910000510 noble metal Inorganic materials 0.000 description 4
- 229910052698 phosphorus Inorganic materials 0.000 description 4
- 239000011574 phosphorus Substances 0.000 description 4
- 238000000623 plasma-assisted chemical vapour deposition Methods 0.000 description 4
- 229910052709 silver Inorganic materials 0.000 description 4
- 239000004332 silver Substances 0.000 description 4
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 3
- 229910021418 black silicon Inorganic materials 0.000 description 3
- 239000008367 deionised water Substances 0.000 description 3
- 229910021641 deionized water Inorganic materials 0.000 description 3
- 238000001035 drying Methods 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 230000007935 neutral effect Effects 0.000 description 3
- 239000003921 oil Substances 0.000 description 3
- 238000009279 wet oxidation reaction Methods 0.000 description 3
- 229910000838 Al alloy Inorganic materials 0.000 description 2
- 229910019213 POCl3 Inorganic materials 0.000 description 2
- 229910000676 Si alloy Inorganic materials 0.000 description 2
- 229910052581 Si3N4 Inorganic materials 0.000 description 2
- XNRNVYYTHRPBDD-UHFFFAOYSA-N [Si][Ag] Chemical compound [Si][Ag] XNRNVYYTHRPBDD-UHFFFAOYSA-N 0.000 description 2
- CSDREXVUYHZDNP-UHFFFAOYSA-N alumanylidynesilicon Chemical compound [Al].[Si] CSDREXVUYHZDNP-UHFFFAOYSA-N 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000007688 edging Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 238000005530 etching Methods 0.000 description 2
- 239000002923 metal particle Substances 0.000 description 2
- 239000004570 mortar (masonry) Substances 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- XHXFXVLFKHQFAL-UHFFFAOYSA-N phosphoryl chloride Substances ClP(Cl)(Cl)=O XHXFXVLFKHQFAL-UHFFFAOYSA-N 0.000 description 2
- 239000005360 phosphosilicate glass Substances 0.000 description 2
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 239000002699 waste material Substances 0.000 description 2
- 238000004065 wastewater treatment Methods 0.000 description 2
- 238000003466 welding Methods 0.000 description 2
- 239000002585 base Substances 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 239000011267 electrode slurry Substances 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 230000031700 light absorption Effects 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910021645 metal ion Inorganic materials 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 238000007747 plating Methods 0.000 description 1
- 238000010248 power generation Methods 0.000 description 1
- 239000010970 precious metal Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 239000002210 silicon-based material Substances 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 238000001039 wet etching Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/02—Details
- H01L31/0236—Special surface textures
- H01L31/02363—Special surface textures of the semiconductor body itself, e.g. textured active layers
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/18—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof
- H01L31/1804—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof comprising only elements of Group IV of the Periodic System
- H01L31/182—Special manufacturing methods for polycrystalline Si, e.g. Si ribbon, poly Si ingots, thin films of polycrystalline Si
Abstract
The application provides a texturing method for a diamond wire-electrode cutting polycrystalline silicon wafer, which comprises the following steps: cleaning and pretreating a diamond wire-cut polycrystalline silicon wafer, and forming a silicon dioxide film layer on the surface of the diamond wire-cut polycrystalline silicon wafer; and carrying out acid texturing on the diamond wire-electrode-cutting polycrystalline silicon wafer with the silicon dioxide film layer to obtain a textured silicon wafer. The texturing method is simple, strong in operability, low in cost and environment-friendly, and a uniform textured structure with low reflectivity can be formed through a conventional acid texturing process after a silicon dioxide film layer is formed. The application also provides a texturing silicon wafer prepared by the texturing method and a solar cell prepared from the texturing silicon wafer.
Description
Technical Field
The application belongs to the technical field of polycrystalline silicon wafer texturing, and particularly relates to a texturing method of a diamond wire-cutting polycrystalline silicon wafer, a textured silicon wafer and a solar cell.
Background
Solar cell photovoltaic power generation is an important approach to solve the global energy crisis and environmental pollution problems, and nearly 90% of the solar cell is a silicon wafer solar cell. In recent years, the diamond wire cutting technology is beginning to be applied to the cutting production of crystal silicon wafers, and compared with the traditional mortar wire cutting technology, the diamond wire cutting technology has the advantages of high cutting rate, high utilization rate of silicon materials, environmental protection, low cost and the like, and gradually becomes the mainstream technology of silicon wafer cutting. However, the diamond wire-cut silicon wafer has less and shallow surface damage and high surface reflectivity, and is processed by a conventional acid texturing process, so that an ideal textured structure is difficult to obtain, and the reflectivity after texturing cannot be reduced to the existing industrial standard, thereby affecting the efficiency of a battery prepared from the textured structure.
The metal ion assisted texturing technology (i.e. black silicon process) is a method developed in recent years and capable of solving texturing of diamond wire cut silicon wafers, wherein nano noble metal particles are generated on the surface of the silicon wafer in advance through reaction and serve as catalytic sites for acid corrosion, and a hole structure with a light trapping effect is formed below the nano noble metal particles. However, although the black silicon process is compatible with the existing wet etching process, the introduction of noble metals substantially increases the cost, and the subsequent removal difficulty is high, and if the black silicon process is not properly treated, metal pollution is easily caused to the battery piece, thereby affecting the conversion efficiency. Accordingly, there is a need for a low cost, simple texturing process suitable for diamond-cut polycrystalline silicon wafers.
Disclosure of Invention
In view of the above, the present application provides a texturing method for diamond wire-cut polycrystalline silicon wafer, which sequentially performs alkali polishing treatment and formation of SiO on the diamond wire-cut polycrystalline silicon wafer2After the film layer is formed, a textured structure with low reflectivity can be formed through acid texturing treatment.
In a first aspect, the present application provides a texturing method for diamond wire cutting polycrystalline silicon wafer, comprising the following steps:
carrying out alkali polishing treatment on the diamond wire-cut polycrystalline silicon wafer, and then forming a silicon dioxide film layer on the surface of the diamond wire-cut polycrystalline silicon wafer;
and carrying out acid texturing on the diamond wire-electrode-cutting polycrystalline silicon wafer with the silicon dioxide film layer to obtain a textured silicon wafer.
Optionally, the thickness of the silicon dioxide film layer is 2-50 nm.
Preferably, the thickness of the silicon dioxide film layer is 10-40 nm.
Optionally, the forming manner of the silicon dioxide film layer includes one of the following:
performing dry-oxygen thermal oxidation at 600-850 ℃ in an oxygen-containing dry atmosphere; or
Performing wet-oxygen thermal oxidation at 600-850 ℃ under a wet-oxygen atmosphere containing oxygen and water vapor; or
Ozone oxidation is carried out under an ozone atmosphere or in ozone water.
Optionally, the alkali polishing treatment uses a strong alkali solution with the concentration of 7 wt% -11 wt%, the temperature of the alkali polishing treatment is 65-85 ℃, and the treatment time is 150s-240 s.
Optionally, after the alkali polishing treatment, an acid cleaning treatment is further included; the acid cleaning treatment adopts dilute HF solution or mixed solution of HF and hydrochloric acid.
Optionally, the etching solution used for acid etching is a mixed aqueous solution containing nitric acid and hydrofluoric acid.
In the texturing method for diamond wire-cut polycrystalline silicon wafer provided by the first aspect of the application, after alkali polishing treatment is performed on the diamond wire-cut polycrystalline silicon wafer, SiO is formed on the surface of the diamond wire-cut polycrystalline silicon wafer2Film layer of SiO2The film layer can be used as a reaction site in subsequent acid texturing, and is beneficial to forming a uniform textured structure with low reflectivity on the basis of the reaction site, so that a battery with high efficiency can be manufactured from a textured silicon wafer. The method has the advantages of strong operability, low cost, no introduction of noble metal, low wastewater treatment cost and environmental protection.
In a second aspect, the present application provides a texturized silicon wafer produced by the texturizing method of the first aspect of the present application.
The textured structure based on the textured silicon wafer has low reflectivity, and can be manufactured into a solar cell according to the conventional cell manufacturing procedure, so that the efficiency of the cell is higher.
In a third aspect, the present application provides a solar cell prepared from the texturized silicon wafer of the second aspect of the present application. Specifically, diffusion, edging, back PN junction removal and front Phosphorus Silicon Glass (PSG) removal, front deposition of an antireflection film (such as a silicon nitride film), electrode printing, high-temperature sintering, and the like can be sequentially performed.
Detailed Description
The following are exemplary embodiments of the present application and it should be noted that those skilled in the art can make several improvements and modifications without departing from the principle of the present application, and these improvements and modifications should also be construed as the protection scope of the present application.
The embodiment of the application provides a texturing method for a diamond wire cutting polycrystalline silicon wafer, which comprises the following steps:
carrying out alkali polishing treatment on the diamond wire-cut polycrystalline silicon wafer, and then forming a silicon dioxide film layer on the surface of the diamond wire-cut polycrystalline silicon wafer;
and carrying out acid texturing on the diamond wire-electrode-cutting polycrystalline silicon wafer with the silicon dioxide film layer to obtain a textured silicon wafer.
In the texturing method, after alkali polishing treatment is carried out on the diamond wire-cut polycrystalline silicon wafer, SiO is formed on the surface of the diamond wire-cut polycrystalline silicon wafer2Film layer of SiO2The film layer can be used as a reaction site in subsequent acid texturing, and is beneficial to forming a uniform textured structure with low reflectivity on the basis of the reaction site, so that a battery with high efficiency can be manufactured from a textured silicon wafer.
In the application, the alkali polishing treatment is mainly used for removing the line marks, the oil stains on the surface, the uneven natural oxidation layer and the like of the diamond wire-cutting polycrystalline silicon wafer so as to form uniform SiO through subsequent oxidation treatment2And an oxide layer to increase the controllability. The acid washing can remove the residual alkali liquor. Wherein, the solvent cleaning can wash away acid liquor and the like remained in the acid cleaning. Alternatively, the solvent washing may sequentially include one or more of water washing, absolute ethanol washing, and the like.
Optionally, the alkali polishing treatment uses a strong alkali solution with the concentration of 7 wt% -11 wt%, the temperature of the alkali polishing treatment is 65-85 ℃, and the treatment time can be 150s-240 s. Wherein, the alkali polishing under high-temperature concentrated alkali can improve the removal efficiency of oil stains and natural oxidation layers. Optionally, the strong base is KOH and/or NaOH.
In the embodiment of the present application, after the alkali polishing treatment, an acid cleaning treatment is further included. Alternatively, the acid cleaning may employ a dilute HF solution, or a mixed solution of HF and hydrochloric acid, or the like. In one embodiment of the present application, the acid cleaning may be performed using a dilute HF solution having a concentration of 5 to 20 wt%.
In the embodiment of the present application, the formation method of the silicon dioxide film layer is not limited, and dry oxidation, wet oxidation, ozone oxidation, or the like may be used. For example, dry oxidation can be performed at 600 ℃ + 850 ℃ under an oxygen-containing dry atmosphere (e.g., nitrogen or helium can be contained); the wet oxidation can be carried out at 600-850 ℃ under the wet oxygen atmosphere of oxygen and water vapor; the ozone oxidation can be carried out under an ozone atmosphere or in ozonated water.
In the embodiment of the present application, the thickness of the silicon dioxide film layer may be 2 to 50 nm. Thus SiO can be avoided2The thickness of the film layer is too thin to lead to form a uniform suede structure in the subsequent wet acid texturing process, and SiO can be avoided2The thickness of the film layer is too thick, so that the waste rate of the silicon wafer after texturing in the subsequent processing is higher. Preferably, the thickness of the silicon dioxide film layer is 10-40 nm. Therefore, the suede structure with low waste sheet rate and low emissivity can be better considered.
Alternatively, the texturing solution used for acid texturing may be a mixed aqueous solution including nitric acid and hydrofluoric acid. Wherein the acid texturing solution can etch SiO2And meanwhile, the film layer reacts with the exposed surface of the silicon wafer to form a light-trapping texture structure, so that the surface reflectivity is reduced, and the efficiency of a subsequently manufactured battery can be improved.
The texturing method for the diamond wire-electrode cutting polycrystalline silicon wafer is simple, strong in operability, low in cost, free of introduction of precious metals, low in wastewater treatment cost and environment-friendly. The texturing method can be well matched with a diamond-cut polycrystalline silicon wafer, has good compatibility with the acid texturing process of the existing silicon wafer, and forms SiO after cleaning pretreatment2After the film layer is formed, a conventional acid texturing process is utilized, a textured structure with uniform corrosion on the whole surface can be obtained, and the reflectivity is low.
Correspondingly, the embodiment of the application also provides a textured silicon wafer, and the textured silicon wafer can be prepared by adopting the texturing method in the embodiment of the application.
The texture surface of the textured silicon wafer is uniform, the reflectivity is low, the textured silicon wafer can be manufactured into a photovoltaic cell according to conventional cell manufacturing procedures (including diffusion, edge removal, deposition of an antireflection film and the like), the photoelectric efficiency of the obtained cell is improved, and therefore the application of a diamond wire cutting silicon wafer technology is promoted.
The embodiment of the application also provides a solar cell, which is prepared from the texturing silicon wafer. Specifically, diffusion, edging, back PN junction removal and front Phosphorus Silicon Glass (PSG) removal, front deposition of an antireflection film (such as a silicon nitride film), electrode printing, high-temperature sintering, and the like can be sequentially performed.
The texture surface of the texture-making silicon wafer is uniform and low in reflectivity, and the efficiency of a solar cell made of the texture-making silicon wafer is high.
Specifically, the diffusion may be conducted at a temperature of 750-880 ℃ with N being introduced2、POCl3And O2And performing phosphorus diffusion treatment to form an N-type layer on the surface of the P-type silicon wafer to form a PN junction, wherein the sheet resistance of the silicon wafer after phosphorus diffusion is 85-120 omega/sq.
PN junctions and phosphosilicate glass (PSG) are formed on the front surface, the periphery and the back surface of the diffused silicon wafer, for a subsequent battery, only the PN junctions on the front surface are needed, if the PN junctions on other places are not removed, the electric leakage of the battery is increased, and if the PSG on the back surface is not removed, the battery efficiency is also seriously influenced. Alternatively, the peripheral edge of the diffused silicon wafer and the PN junction on the back surface can be removed by using a mixed solution of HF and nitric acid, and phosphosilicate glass (PSG) on the back surface can be removed by using an HF solution.
Alternatively, the front-side deposition antireflection film can be realized by the following method: placing a silicon wafer to be coated in a furnace tube of Plasma Enhanced Chemical Vapor Deposition (PECVD) equipment, and introducing SiH at the temperature of 400-4And NH3And forming the SiNx antireflection film under the high-frequency glow discharge condition. Wherein, the thickness of the SiNx film can be 77-83nm, and the refractive index is 2.06-2.12.
Optionally, the printed electrode comprises: and printing back silver paste and back aluminum paste on the back of the silicon wafer with the front plated with the antireflection film to form a back electric field, and printing positive electrode silver paste on the front of the silicon wafer to form a positive electric field. The back electric field can passivate back defects, improve efficiency, facilitate assembly welding and the like; the positive battery can collect the current generated by the front side and conduct it out.
Alternatively, the sintering may be performed at temperatures of 300 ℃ - > 900 ℃. The organic matters in the printed electrode slurry can be dried and removed by sintering, and the forming of silicon-aluminum alloy, silver-silicon alloy and the like is facilitated, so that better ohmic contact is formed in the battery.
The present application is further illustrated by the following specific examples.
Example 1
A texturing method for a diamond wire cutting polycrystalline silicon wafer comprises the following steps:
(1) cleaning pretreatment: firstly, carrying out alkali polishing treatment on a diamond wire-cut polycrystalline silicon wafer for 180s at 85 ℃ by using 10 wt% KOH solution, washing with water, then carrying out acid cleaning by using a mixed solution of hydrofluoric acid and hydrochloric acid, then cleaning with deionized water until the silicon wafer is neutral, and finally drying;
(2) and (3) oxidation: placing the cleaned and pretreated polycrystalline silicon wafer in a chain furnace, introducing nitrogen at a flow rate of 5L/min, introducing oxygen at a flow rate of 0.8L/min, and performing dry-oxygen thermal oxidation at 800 deg.C for 20min to form SiO with a thickness of 40nm2A film layer;
(3) and (3) texturing by using a conventional acid: will be provided with SiO2And placing the diamond wire-cutting polycrystalline silicon wafer of the film layer into an acid texturing solution, wherein the acid texturing solution is prepared from a raw material comprising 4: 1: 2 (65 wt%), hydrofluoric acid (49 wt%) and water, and acid texturing at 8 ℃ for 120s to obtain textured silicon wafers.
The textured surface of the textured silicon wafer in the embodiment 1 is uniform in size distribution, the average reflectivity of the textured silicon wafer in the wave band of 400nm-1000nm is 21%, and the reflectivity of the textured silicon wafer is basically equivalent to the reflectivity of a polycrystalline silicon wafer cut by mortar after being textured by the conventional acid in the step (3).
Further, in order to highlight the advantageous effects of the present invention, the following comparative examples 1 to 2 were provided.
Comparative example 1
A texturing method of a diamond wire-cut polycrystalline silicon wafer, which is different from embodiment 1 in that: the treatment of the above step (2) is not performed. That is, the diamond-wire-cut polycrystalline silicon wafer was subjected to the treatments of only step (1) and step (3) of example 1 in this order to obtain a textured silicon wafer.
Comparative example 2
A texturing method of a diamond wire-cut polycrystalline silicon wafer, which is different from example 1 in that the cleaning pretreatment of step (1) is not alkali-polished, and only the following treatments are carried out: and carrying out acid cleaning on the diamond wire-cutting polycrystalline silicon wafer by using a mixed solution of hydrofluoric acid and hydrochloric acid, then cleaning the diamond wire-cutting polycrystalline silicon wafer by using deionized water until the diamond wire-cutting polycrystalline silicon wafer is neutral, and drying the diamond wire-cutting polycrystalline silicon wafer.
As a result, the reflectivity of the obtained textured silicon wafer of comparative example 1 can reach 27% after the diamond wire-cut polycrystalline silicon wafer is directly subjected to conventional acid texturing, and is much higher than that of the textured silicon wafer of example 1. If the diamond wire-cut polycrystalline silicon wafer is not subjected to alkali polishing cleaning, but is only subjected to oxidation treatment and acid texturing after acid cleaning, the reflectivity of the textured silicon wafer obtained in the comparative example 2 is high and is as high as 30%, which indicates that the acid cleaning cannot effectively remove the wire marks, oil stains and the like of the diamond wire-cut polycrystalline silicon wafer, and further cannot effectively perform subsequent oxidation treatment and the like. The results show that the silicon wafer with lower reflectivity can be obtained by processing the diamond wire cutting polycrystalline silicon wafer by the texturing method provided by the application.
To enrich the application of the present application, the textured silicon wafer prepared in example 1 was made into a battery by the following specific process:
(1) diffusion: placing the P-type texturing silicon wafer in a diffusion furnace, and introducing N at the temperature of 800 DEG C2、POCl3And O2Performing phosphorus diffusion treatment to form an N-type layer on the surface of the P-type silicon wafer to form a PN junction, wherein the sheet resistance of the silicon wafer after phosphorus diffusion is 95 omega/sq;
(2) removing edges, removing back PN junctions and removing PSG on the front surface: adopting a mixed solution of HF and nitric acid to remove PN junctions at the periphery and the back of the diffused silicon wafer, and removing PSG at the back by using an HF solution;
(3)plating a SiNx antireflection film on the front side: placing the treated silicon wafer in a furnace tube of Plasma Enhanced Chemical Vapor Deposition (PECVD) equipment, and introducing SiH at 450 DEG C4And NH3Forming a SiNx antireflection film under a high-frequency glow discharge condition, wherein the thickness of the SiNx film is 79nm, and the refractive index is 2.08;
(4) printing an electrode: printing back silver paste and back aluminum paste on the back of the silicon chip plated with the SiNx film to form a standby electric field so as to passivate back defects, improve efficiency, facilitate component welding and the like; printing positive electrode silver paste on the front surface of the silicon wafer to collect and lead out current generated by the front surface; wherein, the back pole is wet and heavy: 0.037g/pcs, back field wet weight: 1.35 g/pcs; anode wet weight: 0.1 g/pcs;
(5) and (3) sintering: and sintering the silicon wafer with the printed electrode in a furnace at 600 ℃ to dry organic matters in the slurry and form silicon-aluminum alloy, silver-silicon alloy and the like, so that better ohmic contact is formed inside the battery, and the battery piece is obtained.
In addition, to further highlight the beneficial effects of the present application, the texturized silicon wafer of comparative example 1 above was also fabricated into a battery (denoted as comparative example 1 battery) in the manner provided for the fabrication of the battery in example 1, and performance comparisons were made with the battery fabricated from the texturized silicon wafer of example 1 of the present application, and the results are summarized in table 1 below.
Table 1 results of comparing the performance of the example battery with that of the comparative example battery
In table 1 above, Isc represents the short-circuit current of the battery, Uoc represents the open-circuit voltage, FF represents the fill factor, Eta represents the conversion efficiency of the battery, IRev2 represents the leakage current, Rs represents the series resistance of the battery, and Rsh represents the parallel resistance of the battery.
As can be seen from table 1, the short-circuit current (Isc) of the cell of the embodiment of the present application is greater than the Isc of the comparative cell, which is mainly because the diamond wire-cut silicon wafer is processed by the texturing method provided by the present application, the textured structure of the obtained textured silicon wafer is more uniform, the reflectivity is lower (lower than that after the diamond wire-cut polycrystalline silicon wafer is directly textured with conventional acid), and therefore, the light absorption to sunlight becomes more, so that the efficiency (Eta) of the cell is also improved. In addition, the efficiency Eta of the cell made from the textured silicon wafer of comparative example 2 was only 18.72%, which is also much lower than the cell made from the textured silicon wafer of example 1 of the present application.
Example 2
A texturing method for a diamond wire cutting polycrystalline silicon wafer comprises the following steps:
(1) cleaning pretreatment: firstly, carrying out alkali polishing treatment on a diamond wire-cut polycrystalline silicon wafer for 150s at 70 ℃ by using a KOH solution with the concentration of 8 wt%, washing the diamond wire-cut polycrystalline silicon wafer by using a mixed solution of hydrofluoric acid and hydrochloric acid after washing, then washing the diamond wire-cut polycrystalline silicon wafer by using deionized water until the diamond wire-cut polycrystalline silicon wafer is neutral, and then washing the diamond wire-cut polycrystalline silicon wafer by using ethanol and drying the diamond wire-cut polycrystalline silicon wafer;
(2) and (3) oxidation: placing the cleaned and pretreated polycrystalline silicon wafer in ozone water with concentration of 25ppm, and performing wet oxidation for 1min to form SiO with thickness of about 2-5nm2A film layer;
(3) and (3) texturing by using a conventional acid: will be provided with SiO2And (3) placing the diamond wire-cut polycrystalline silicon wafer of the film layer into a mixed aqueous solution containing hydrofluoric acid and nitric acid, and performing acid texturing for 120s at the temperature of 8 ℃ to obtain a textured silicon wafer.
The textured silicon wafer obtained in example 2 was measured to have a reflectance of 25%, and the cell prepared from the textured silicon wafer had an efficiency Eta of 18.95%.
Example 3
A texturing method of diamond wire-cut polycrystalline silicon wafer is different from that of example 1 in that SiO2The thickness of the film layer was 20 nm.
The textured silicon wafer obtained in example 3 was found to have a reflectance of 22% and the cell prepared from the textured silicon wafer had an efficiency Eta of 19.07%.
Example 4
A texturing method of diamond wire-cut polycrystalline silicon wafer is different from that of example 1 in that SiO2The thickness of the film layer is in the range of 10-12 nm.
The reflectance of the texturized silicon wafer of example 4 was measured to be 23% and the efficiency Eta of the cell made from the texturized silicon wafer was 19.01%.
The above-described embodiments are merely illustrative of several exemplary embodiments of the present application, which are described in more detail and detail, but are not to be construed as limiting the scope of the present application. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application.
Claims (10)
1. A texturing method for a diamond wire-cut polycrystalline silicon wafer is characterized by comprising the following steps:
carrying out alkali polishing treatment on the diamond wire-cut polycrystalline silicon wafer, and then forming a silicon dioxide film layer on the surface of the diamond wire-cut polycrystalline silicon wafer;
and carrying out acid texturing on the diamond wire-electrode-cutting polycrystalline silicon wafer with the silicon dioxide film layer to obtain a textured silicon wafer.
2. The texturing method of claim 1, wherein the thickness of the silica film layer is 2 to 50 nm.
3. The texturing method of claim 2, wherein the thickness of the silicon dioxide film layer is 10 to 40 nm.
4. The texturing method of claim 1, wherein the silicon dioxide film layer is formed in a manner comprising one of:
performing dry-oxygen thermal oxidation at 600-850 ℃ in an oxygen-containing dry atmosphere; or alternatively
Performing wet-oxygen thermal oxidation at 600-850 ℃ under a wet-oxygen atmosphere containing oxygen and water vapor; or
Ozone oxidation is carried out under an ozone atmosphere or in ozone water.
5. The texturing method according to claim 1, wherein the alkali polishing treatment uses a strong alkali solution with a concentration of 7 wt% to 11 wt%, the temperature of the alkali polishing treatment is 65 to 85 ℃, and the treatment time is 150s to 240 s.
6. The texturing method according to claim 1, further comprising an acid cleaning treatment after the alkali polishing treatment, wherein the acid cleaning treatment uses a dilute HF solution or a mixed solution of HF and hydrochloric acid.
7. The method according to claim 1, wherein the acid texturing solution is a mixed aqueous solution containing nitric acid and hydrofluoric acid.
8. A texturized silicon wafer, wherein said texturized silicon wafer has been produced by the texturizing method according to any one of claims 1-7.
9. A solar cell prepared from the texturized silicon wafer of any one of claims 1-7.
10. The solar cell of claim 1, wherein the textured silicon wafer is obtained by sequentially performing diffusion, edge removal, back PN junction removal, front phosphorus-silicon glass removal, antireflection film deposition, electrode printing and high-temperature sintering on the textured silicon wafer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011436401.3A CN114628539A (en) | 2020-12-10 | 2020-12-10 | Texturing method for diamond wire-cut polycrystalline silicon wafer, textured silicon wafer and solar cell |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011436401.3A CN114628539A (en) | 2020-12-10 | 2020-12-10 | Texturing method for diamond wire-cut polycrystalline silicon wafer, textured silicon wafer and solar cell |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114628539A true CN114628539A (en) | 2022-06-14 |
Family
ID=81895937
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011436401.3A Pending CN114628539A (en) | 2020-12-10 | 2020-12-10 | Texturing method for diamond wire-cut polycrystalline silicon wafer, textured silicon wafer and solar cell |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114628539A (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104073883A (en) * | 2014-06-11 | 2014-10-01 | 邬时伟 | Texturing process for polycrystalline silicon solar cell slice |
| CN104485386A (en) * | 2014-11-21 | 2015-04-01 | 广东爱康太阳能科技有限公司 | Texturization method for polycrystalline silicon solar battery |
| CN105576080A (en) * | 2016-01-29 | 2016-05-11 | 江西赛维Ldk太阳能高科技有限公司 | Single-surface texturing method for diamond wire cut polycrystalline silicon wafer, and diamond wire cut polycrystalline silicon wafer with single surface textured |
| CN108505121A (en) * | 2018-03-15 | 2018-09-07 | 张家港国龙光伏科技有限公司 | A kind of etching method improving polysilicon chip cashmere output rate |
| US20190067496A1 (en) * | 2016-04-29 | 2019-02-28 | Nanjing Tech University | Texturing Method for Diamond Wire Cut Polycrystalline Silicon Slice |
-
2020
- 2020-12-10 CN CN202011436401.3A patent/CN114628539A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104073883A (en) * | 2014-06-11 | 2014-10-01 | 邬时伟 | Texturing process for polycrystalline silicon solar cell slice |
| CN104485386A (en) * | 2014-11-21 | 2015-04-01 | 广东爱康太阳能科技有限公司 | Texturization method for polycrystalline silicon solar battery |
| CN105576080A (en) * | 2016-01-29 | 2016-05-11 | 江西赛维Ldk太阳能高科技有限公司 | Single-surface texturing method for diamond wire cut polycrystalline silicon wafer, and diamond wire cut polycrystalline silicon wafer with single surface textured |
| US20190067496A1 (en) * | 2016-04-29 | 2019-02-28 | Nanjing Tech University | Texturing Method for Diamond Wire Cut Polycrystalline Silicon Slice |
| CN108505121A (en) * | 2018-03-15 | 2018-09-07 | 张家港国龙光伏科技有限公司 | A kind of etching method improving polysilicon chip cashmere output rate |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| TWI669830B (en) | Method for manufacturing local back contact solar cell | |
| CN105226112B (en) | A kind of preparation method of efficient crystal silicon solar batteries | |
| CN111668345A (en) | Solar cell and preparation method thereof | |
| CN112542531B (en) | Silicon wafer pretreatment and heterojunction battery preparation method | |
| Barrio et al. | Optimisation of NaOH texturisation process of silicon wafers for heterojunction solar-cells applications | |
| CN111933752A (en) | Solar cell and preparation method thereof | |
| CN112510121B (en) | Pre-and-post alkali polishing protection process for perc battery | |
| TWI722078B (en) | Manufacturing method of photoelectric conversion device | |
| US9123840B2 (en) | Solar cell element manufacturing method, solar cell element, and solar cell module | |
| CN106711280B (en) | A kind of production method of N-type double-side cell | |
| CN110890432A (en) | Efficient polycrystalline silicon solar cell and preparation method thereof | |
| Wang et al. | Etch-back silicon texturing for light-trapping in electron beam evaporated thin-film polycrystalline silicon solar cells | |
| CN116741877A (en) | TBC battery preparation method and TBC battery | |
| Chaoui et al. | Porous silicon antireflection layer for solar cells using metal‐assisted chemical etching | |
| Chen et al. | Improvement of conversion efficiency of multi-crystalline silicon solar cells using reactive ion etching with surface pre-etching | |
| Hsu et al. | High-efficiency 6′′ multicrystalline black solar cells based on metal-nanoparticle-assisted chemical etching | |
| CN113921649A (en) | Preparation method of silicon-based heterojunction solar cell | |
| CN105529380A (en) | Preparation method for single crystalline silicon solar cell piece with polished back surface | |
| Zhou et al. | Experimental study on the elimination of over-plating problems in industrial manufacturing of large-area acidic-textured laser-doped multi-crystalline solar cells | |
| CN113257954B (en) | Method for solving poor EL of alkali-polished SE-PERC battery | |
| CN114628539A (en) | Texturing method for diamond wire-cut polycrystalline silicon wafer, textured silicon wafer and solar cell | |
| CN111040766B (en) | Polycrystalline silicon wafer texturing solution, preparation method of black silicon material and application of black silicon material in accelerating PERC battery LeTID recovery | |
| CN112531074A (en) | Back passivation solar cell and preparation method thereof | |
| CN113241391A (en) | PERC battery processing technology for reducing back surface field recombination loss | |
| Chaoui et al. | Improvement of screen-printed textured monocrystalline silicon solar cell performance by metal-assisted chemical etching |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |