CN108511539B - Preparation method of solar cell - Google Patents
Preparation method of solar cell Download PDFInfo
- Publication number
- CN108511539B CN108511539B CN201710111365.5A CN201710111365A CN108511539B CN 108511539 B CN108511539 B CN 108511539B CN 201710111365 A CN201710111365 A CN 201710111365A CN 108511539 B CN108511539 B CN 108511539B
- Authority
- CN
- China
- Prior art keywords
- solar cell
- volume
- hydrofluoric acid
- silicon substrate
- 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.)
- Active
Links
- 238000002360 preparation method Methods 0.000 title claims abstract description 10
- 238000004519 manufacturing process Methods 0.000 claims abstract description 10
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 146
- 229910052710 silicon Inorganic materials 0.000 claims description 145
- 239000010703 silicon Substances 0.000 claims description 145
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 claims description 129
- 239000000758 substrate Substances 0.000 claims description 111
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims description 62
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 49
- 238000009792 diffusion process Methods 0.000 claims description 35
- 238000000034 method Methods 0.000 claims description 35
- 239000002253 acid Substances 0.000 claims description 32
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims description 31
- 238000005530 etching Methods 0.000 claims description 31
- 229910017604 nitric acid Inorganic materials 0.000 claims description 31
- 239000000243 solution Substances 0.000 claims description 29
- 238000005520 cutting process Methods 0.000 claims description 27
- 239000002923 metal particle Substances 0.000 claims description 25
- 239000007788 liquid Substances 0.000 claims description 21
- 238000004140 cleaning Methods 0.000 claims description 20
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 18
- 229910021645 metal ion Inorganic materials 0.000 claims description 18
- 239000003513 alkali Substances 0.000 claims description 15
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 claims description 9
- 238000001035 drying Methods 0.000 claims description 9
- 238000007747 plating Methods 0.000 claims description 9
- 239000011259 mixed solution Substances 0.000 claims description 8
- 229910021426 porous silicon Inorganic materials 0.000 claims description 8
- 238000000151 deposition Methods 0.000 claims description 6
- 150000003839 salts Chemical class 0.000 claims description 6
- 239000011521 glass Substances 0.000 claims description 5
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims description 4
- 238000005498 polishing Methods 0.000 claims description 4
- HIVGXUNKSAJJDN-UHFFFAOYSA-N [Si].[P] Chemical compound [Si].[P] HIVGXUNKSAJJDN-UHFFFAOYSA-N 0.000 claims description 2
- 229910021529 ammonia Inorganic materials 0.000 claims 1
- 238000006243 chemical reaction Methods 0.000 abstract description 25
- 239000013078 crystal Substances 0.000 abstract description 18
- 235000012431 wafers Nutrition 0.000 description 57
- 239000010410 layer Substances 0.000 description 42
- 229940074355 nitric acid Drugs 0.000 description 27
- 229910003460 diamond Inorganic materials 0.000 description 15
- 239000010432 diamond Substances 0.000 description 15
- 229910021420 polycrystalline silicon Inorganic materials 0.000 description 15
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 14
- 230000000694 effects Effects 0.000 description 14
- 239000008367 deionised water Substances 0.000 description 13
- 229910021641 deionized water Inorganic materials 0.000 description 13
- 238000005516 engineering process Methods 0.000 description 13
- 230000008569 process Effects 0.000 description 13
- 230000000052 comparative effect Effects 0.000 description 12
- 229910052709 silver Inorganic materials 0.000 description 10
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 9
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 9
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 9
- 235000011114 ammonium hydroxide Nutrition 0.000 description 9
- 239000004570 mortar (masonry) Substances 0.000 description 9
- 230000035484 reaction time Effects 0.000 description 9
- 239000004332 silver Substances 0.000 description 9
- 238000012360 testing method Methods 0.000 description 9
- 238000002310 reflectometry Methods 0.000 description 7
- 239000000969 carrier Substances 0.000 description 6
- 230000006798 recombination Effects 0.000 description 6
- SQGYOTSLMSWVJD-UHFFFAOYSA-N silver(1+) nitrate Chemical compound [Ag+].[O-]N(=O)=O SQGYOTSLMSWVJD-UHFFFAOYSA-N 0.000 description 6
- 239000002245 particle Substances 0.000 description 5
- 238000002161 passivation Methods 0.000 description 5
- 238000000623 plasma-assisted chemical vapour deposition Methods 0.000 description 5
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 4
- 101100332285 Saccharomyces cerevisiae (strain ATCC 204508 / S288c) DSS4 gene Proteins 0.000 description 4
- 239000007789 gas Substances 0.000 description 4
- 150000002500 ions Chemical class 0.000 description 4
- 239000011574 phosphorus Substances 0.000 description 4
- 229910052698 phosphorus Inorganic materials 0.000 description 4
- 238000001878 scanning electron micrograph Methods 0.000 description 4
- 239000000377 silicon dioxide Substances 0.000 description 4
- 235000012239 silicon dioxide Nutrition 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- 239000002344 surface layer Substances 0.000 description 4
- 102100023817 26S proteasome complex subunit SEM1 Human genes 0.000 description 3
- 101000684297 Homo sapiens 26S proteasome complex subunit SEM1 Proteins 0.000 description 3
- 101000873438 Homo sapiens Putative protein SEM1, isoform 2 Proteins 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 229910001961 silver nitrate Inorganic materials 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-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
- 230000008901 benefit Effects 0.000 description 2
- 229910021418 black silicon Inorganic materials 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 238000012937 correction Methods 0.000 description 2
- 230000008021 deposition Effects 0.000 description 2
- 230000003670 easy-to-clean Effects 0.000 description 2
- 238000003487 electrochemical reaction Methods 0.000 description 2
- 239000007888 film coating Substances 0.000 description 2
- 238000009501 film coating Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 229910021421 monocrystalline silicon Inorganic materials 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 238000007639 printing Methods 0.000 description 2
- 230000036632 reaction speed Effects 0.000 description 2
- 238000005215 recombination Methods 0.000 description 2
- 238000005245 sintering Methods 0.000 description 2
- 230000004580 weight loss Effects 0.000 description 2
- 239000013585 weight reducing agent Substances 0.000 description 2
- 101710134784 Agnoprotein Proteins 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- YZCKVEUIGOORGS-UHFFFAOYSA-N Hydrogen atom Chemical compound [H] YZCKVEUIGOORGS-UHFFFAOYSA-N 0.000 description 1
- 241000084978 Rena Species 0.000 description 1
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical compound [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 239000002585 base Substances 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 238000012512 characterization method Methods 0.000 description 1
- 238000010668 complexation reaction Methods 0.000 description 1
- 239000008139 complexing agent Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000007667 floating Methods 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 238000009616 inductively coupled plasma Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000002105 nanoparticle Substances 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 229910000510 noble metal Inorganic materials 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 238000001579 optical reflectometry Methods 0.000 description 1
- 239000007800 oxidant agent Substances 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 238000005554 pickling Methods 0.000 description 1
- 238000010248 power generation Methods 0.000 description 1
- 238000002203 pretreatment Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000005488 sandblasting Methods 0.000 description 1
- 238000004626 scanning electron microscopy Methods 0.000 description 1
- 229910000077 silane Inorganic materials 0.000 description 1
- 239000005368 silicate glass Substances 0.000 description 1
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 1
- 229910010271 silicon carbide Inorganic materials 0.000 description 1
- -1 silver amine Chemical class 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 229910021654 trace metal Inorganic materials 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
Images
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
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/547—Monocrystalline silicon PV cells
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
Abstract
The invention provides a preparation method of a solar cell. The surface of the solar cell is provided with cell holes, the opening width of the cell holes is 400-1000 nm, and the depth of the cell holes is 100-400 nm. High photoelectric conversion efficiency, no obvious crystal flower on the appearance and large-scale practical production.
Description
Technical Field
The invention relates to the field of solar cells, in particular to a preparation method of 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. The diamond wire saw cutting technology is applied to the cutting production of crystal silicon wafers in recent years, and compared with the existing mainstream silicon carbide abrasive mortar wire cutting technology, the diamond wire saw cutting technology has the advantages of high cutting rate, small environmental load, small mechanical damage on the surfaces of the silicon wafers, less silicon sawdust, easiness in recovery, and small bending degree and total thickness deviation of the silicon wafers, and the diamond wire saw cutting technology can greatly reduce the cost of polycrystalline silicon wafers. Compared with the existing mortar wire saw cutting silicon wafer, the surface of the diamond wire saw cutting silicon wafer always presents obvious cutting lines and higher surface reflectivity. In fact, the micro roughness of the diamond wire-cut silicon wafer is smaller than that of the mortar-cut silicon wafer, so that the performance of the solar cell is not influenced by the cutting lines, but the photovoltaic market reflection shows that the cutting lines can sufficiently block the market development. Theories and practices show that in the anisotropic alkali etching texturing process, diamond cutting lines on the monocrystalline silicon wafer can be completely removed, so that the diamond cutting technology is applied to the production of the monocrystalline silicon wafer. However, for the diamond-cut polycrystalline silicon wafer, the reflectivity of the diamond-cut polycrystalline silicon wafer is not reduced to the current industrial standard by adopting the conventional mixed acid etching texturing, and the diamond-cut polycrystalline silicon wafer has obvious appearance defects such as line marks and the like, so that the battery efficiency is seriously reduced. If the polycrystalline silicon wafer is etched by alkali, the surface of the crystal grain close to the (001) orientation has a good texturing effect, micro scratches and macro reciprocating lines can be completely removed, but the micro scratches and the macro reciprocating lines have no effect on the crystal grains of other orientations, and the efficiency of the prepared battery is still low.
In order to solve the texturing problem of the diamond-cut silicon wafer, some photovoltaic enterprises in Japan introduce a sand blasting pretreatment technology to remove cutting lines on the surface of the diamond wire-cut polycrystalline silicon wafer, but the additional cost is high and the equipment is complex. In addition, a few potential diamond wire cutting silicon wafer texturing technologies, such as a plasma reactive etching (IRE) method, require equipment which is more complex and expensive than the existing production line technology, and the transfer of mature technologies to the production line is a long time.
The metal ion assisted texturing (black silicon) technology is a method for better solving texturing of diamond wire silicon wafer cutting in recent years. The technology adopts noble metal ions such as Au, Ag and the like, hydrogen peroxide and hydrofluoric acid to form combined etching liquid, in the process of etching a silicon wafer, the metal ions are reduced into nano particles by silicon and are attached to the surface of the silicon wafer, then the metal particles are used as a cathode, the silicon is used as an anode, and a micro electrochemical reaction channel is formed on the surface of the silicon. The hydrogen peroxide acts on the surface of the silicon to generate silicon dioxide, and hydrofluoric acid carries out complexation on the silicon dioxide to generate a complex soluble in water, so that micro-nano holes are quickly etched below the nano metal particles, and the hole structure has a good light trapping effect. However, in actual production, the metal ions assist in forming the micro-nano textured surface, although the surface reflectivity is reduced, the efficiency of the battery is not improved, and the appearance is also poor, so that how to apply the metal ion assisted texturing (black silicon) technology to the production practice in a large scale is still a problem which needs to be solved urgently at present.
Disclosure of Invention
The invention provides a preparation method of a solar cell, which is high in photoelectric conversion efficiency, free of obvious crystal grains in appearance and capable of realizing large-scale practical production, and aims to solve the technical problem that the existing metal ion assisted texturing technology cannot be applied in large scale in practical production.
The invention aims to provide a preparation method of the solar cell, which comprises the following steps: forming a substrate hole with an opening width of 500-1200 nm and a depth of 200-500 nm on the surface of a silicon substrate, and then diffusing and attaching an antireflection film to obtain a solar cell;
the method comprises the following steps: s11, depositing metal particles: placing the silicon substrate in a mixed solution containing metal ion salt and hydrofluoric acid to deposit metal particles;
s21, forming micro-nano holes: placing the silicon substrate obtained in the step S11 in an etching solution containing hydrofluoric acid and hydrogen peroxide for etching; the volume of hydrogen peroxide in the etching liquid is as follows: volume of hydrofluoric acid: volume of water is (2-5): 1: (5-8); in the step S21, the mass concentration of the hydrogen peroxide is 30-32%; the mass concentration of the hydrofluoric acid is 49-50%;
s31, micro-nano hole cutting and expanding: putting the silicon substrate obtained in the step S21 into a mixed acid liquid containing nitric acid and hydrofluoric acid, wherein the volume of the nitric acid in the mixed acid liquid is as follows: volume of hydrofluoric acid: the volume of water is (5.0-9.0) and (7-10) is 1; in the step S31, the mass concentration of the nitric acid is 65-68%; the mass concentration of the hydrofluoric acid is 49-50%;
s41, removing porous silicon and correcting micro-nano holes: placing the silicon substrate obtained in the step S31 in alkali liquor to remove the porous silicon layer and correct the micro-nano holes;
s51, removing metal particles;
s61, diffusion;
s71, plating an antireflection film;
s81, preparing a solar cell electrode;
and (5) preparing the solar cell.
The inventor of the invention discovers through long-term practical research that the size, the direction and the depth of the opening of the micro-nano hole are different due to the boundary effect and the crystal orientation of the silicon substrate, so that barriers are formed for reaction gases of subsequent diffusion, PECVD (plasma enhanced chemical vapor deposition) and other processes to enter the hole. In addition, the surface area of the textured surface which is greatly increased can also become a recombination center of a carrier, so that the photoelectric conversion efficiency of the solar cell which is actually produced in a large scale is low.
On the basis, the invention obtains micro-nano holes with specific size and depth by specific metal ion assisted texturing, and prepares a polycrystalline silicon wafer cut by a diamond wire into a polycrystalline silicon solar cell with a surface having a special hole structure by the processes of diffusion, antireflection film plating and the like, for a common solar cell, the solar cell comprises a silicon substrate, a diffusion layer and an antireflection film layer, wherein the diffusion layer and the antireflection film layer are attached to the surface of the silicon substrate, namely, the invention obtains the substrate holes with specific size and depth on the surface of the silicon substrate by the specific metal ion assisted texturing, the diffusion layer and the antireflection film layer positioned at the substrate holes are attached to the hole wall and the bottom of the substrate holes to form the cell holes with the special hole structure, and the photoelectric conversion efficiency of the solar cell with the special structure is unexpectedly found to be remarkably improved and even higher than that the cell obtained by the conventional mortar silicon wafer acid texturing, and the appearance is close to that of a mortar silicon slice battery piece, and no obvious crystal flower phenomenon exists, the reason is presumably that 1, the battery piece holes with specific size and depth have excellent light trapping performance, and compared with the traditional acid textured mortar cutting conventional battery piece, the light reflection loss can be greatly reduced. 2. The holes of the substrate enable the diffusion layer and the antireflection film layer to be uniformly distributed in the holes, the passivation effect on the silicon surface layer in the holes is good, and the residual nano metal particles subjected to metal ion assisted texturing are easy to clean out, so that the recombination center of current carriers is eliminated. Particularly, the prepared substrate hole with the bottom surface width smaller than the opening width and the specific size and depth is provided with an inverted trumpet-shaped structure, as shown in figure 1, in the diffusion and antireflection film plating process of the cell, the structure enables working gas to be easily diffused and cover the wall surface and the bottom of the hole, so that the prepared diffusion layer and the prepared antireflection film layer are relatively uniformly distributed in the hole, the passivation effect on the silicon surface layer in the hole is good, and the performance of the solar cell can be further improved. In addition, with the holes of the inverted trumpet-shaped structure, residual nano metal particles are easier to clean, and recombination centers of carriers are eliminated. The solar cell prepared by the invention has greatly improved efficiency compared with the solar cell prepared by cutting the silicon wafer by the existing diamond wire saw, and even compared with the cell prepared by cutting the silicon wafer by the conventional mortar, the absolute value of the average photoelectric efficiency of the solar cell prepared by the invention can be improved by more than 0.30%.
Drawings
Fig. 1 is a schematic view of a partially enlarged cross section of a micro-nano hole, i.e., a substrate hole, of a silicon substrate prepared in embodiment 1 of the present invention, where d1 is an opening width of the micro-nano hole, d2 is a width of a bottom surface of the micro-nano hole, h is a depth of the micro-nano hole, and α is an included angle between a side surface and the bottom surface of the micro-nano hole.
Fig. 2 is a partially enlarged sectional view of a cell hole prepared in example 1 of the present invention.
FIG. 3 is an SEM image (magnification of 50000 times) of the pores of the substrate prepared in example 1 of the present invention.
FIG. 4 is an SEM image (magnification 20000 times) of the holes of the battery plate prepared in example 1 of the present invention.
Fig. 5 is an SEM image (magnified 50000 times) of micro-nano holes on the surface of the silicon substrate prepared in comparative example 1 of the present invention.
Fig. 6 is an SEM image (magnified 10000 times) of micro pits of the surface of the silicon substrate prepared in comparative example 4 of the present invention.
FIG. 7 is a schematic external view of a silicon substrate prepared in example 1 of the present invention.
FIG. 8 is a schematic external view of a silicon substrate prepared in comparative example 1 of the present invention.
FIG. 9 is a schematic external view of a silicon substrate prepared in comparative example 4 of the present invention.
Fig. 10 is a physical appearance diagram of the solar cell sheet prepared in example 1 of the present invention.
Fig. 11 is a view showing an appearance of a solar cell sheet prepared in comparative example 1 of the present invention.
Fig. 12 is a view showing an appearance of a solar cell sheet prepared in comparative example 4 of the present invention.
Detailed Description
In order to make the technical problems, technical solutions and advantageous effects solved by the present invention more clearly apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
The invention provides a solar cell, wherein the surface of the solar cell is provided with cell holes, the opening width of the cell holes is 400-1000 nm, and the depth of the cell holes is 100-400 nm. Preferably, the width of the opening of the battery piece hole is 500-800 nm, and the depth of the battery piece hole is 150-300 nm. The photoelectric conversion efficiency of the solar cell can be remarkably improved, and the prepared solar cell has no obvious crystal flower in appearance.
Preferably, the width of the bottom surface of the hole of the battery piece is smaller than the width of the opening. For example, a flared structure, as shown in FIG. 2, where d2 is less than d1, can greatly reduce the light reflection loss. The common solar cell comprises a silicon substrate, and a diffusion layer and an antireflection film layer which are attached to the surface of the silicon substrate, wherein the solar cell can be obtained by forming substrate holes in the shape on the surface of the silicon substrate and then preparing the uniform diffusion layer and the antireflection film layer. The solar cell has good collection effect of photon-generated carriers, high short-circuit current and open-circuit voltage, and improved average photoelectric efficiency (absolute value) by more than 0.30% compared with the cell prepared by conventional mortar silicon-cutting wafers.
More preferably, as shown in fig. 2, an included angle α between the side surface and the bottom surface of the cell hole is 100 to 135 degrees, and still more preferably, an included angle between the side surface and the bottom surface of the cell hole is 110 to 120 degrees, so that the hole structure is further optimized, and the solar cell obtained by specifying the opening width, the inclination and the depth has better performance.
The solar cell generally comprises a silicon substrate, a diffusion layer and an antireflection film layer, wherein the diffusion layer and the antireflection film layer are attached to the surface of the silicon substrate, the surface of the silicon substrate is provided with a substrate hole, and the diffusion layer and the antireflection film layer which are positioned at the substrate hole are attached to the side surface and the bottom surface, namely the hole wall and the bottom of the substrate hole to form the cell hole. Preferably, the opening width of the substrate hole is 500-1200 nm, preferably 600-1000 nm; the depth of the holes in the substrate is 200-500 nm, preferably 300-400 nm. The diffusion layer and the antireflection film layer are uniformly distributed in the holes, the passivation effect on the silicon surface layer in the holes is good, the residual nano metal particles subjected to metal ion assisted texturing are easy to clean, and the recombination center of current carriers is eliminated.
Preferably, the thickness of the antireflection film layer is 80-90 nm.
The invention also provides a preparation method of the solar cell, which comprises the following steps: and forming a substrate hole with the opening width of 500-1200 nm and the depth of 200-500 nm on the surface of the silicon substrate, and then diffusing and attaching an antireflection film to obtain the solar cell.
The specific steps may include:
s11, depositing metal particles: placing the silicon substrate in a mixed solution containing metal ion salt and hydrofluoric acid to deposit metal particles; specifically, the silicon substrate may be placed in a salt containing a metal ion (e.g., AgNO)3) And in the mixed liquid tank of hydrofluoric acid, reducing metal ions into nano metal particles by silicon and depositing the nano metal particles on the surface of the silicon substrate. Preferably, in step S11, the concentration of the metal ions in the mixed solution of the salt containing the metal ions and the hydrofluoric acid is 10 to 100ppm, and the volume concentration of the hydrofluoric acid in the mixed solution is 0.5 to 10%; wherein the mass concentration of the hydrofluoric acid is 49-50%; further optimizing the particle size of the generated nano metal particles and the distribution on the surface of the silicon substrate. Preferably, the reaction temperature in the step is 20-30 ℃, and the reaction time is 50-150 s. Generally, after the reaction is finished, deionized water can be used for cleaning for 120-240 s.
Preferably, the silicon substrate is pretreated before step S11, and the pretreatment of the present invention is not limited to any of the various pretreatments known to those skilled in the art, and the present invention is preferably:
s01, primary alkali polishing; preferably, the polycrystalline silicon substrate is initially polished by using a sodium hydroxide or potassium hydroxide solution at a certain temperature to remove oil stains and damage layers on the surface of the silicon substrate, so that a relatively flat micron suede is formed on the surface of the silicon substrate, and then the polycrystalline silicon substrate is cleaned by deionized water for 120-240 seconds. In the stage, the mass concentration of the strong base can be controlled to be 2.0-15 wt%, the temperature can be controlled to be 60-90 ℃, the reaction time can be 1.0-5.0 min, the average weight reduction can be 0.20-0.35 g, and the damaged layer left by the diamond wire cutting silicon wafer can be removed better.
S02, acid cleaning; preferably, the silicon substrate obtained in the step S01 may be cleaned by using dilute nitric acid with a volume concentration of 0.2-2.0%, the cleaning temperature may be normal temperature, the cleaning time may be 50-100 seconds, and then cleaned by using deionized water for 120-240 seconds.
S21, forming micro-nano holes: placing the silicon substrate obtained in the step S11 in an etching solution containing hydrofluoric acid and hydrogen peroxide for etching; the volume of hydrogen peroxide in the etching liquid is as follows: volume of hydrofluoric acid: volume of water is (2-5): 1: (5-8), in the step S21, the mass concentration of the hydrogen peroxide is 30-32%; the mass concentration of the hydrofluoric acid is 49-50%; namely, the hydrogen peroxide and the hydrofluoric acid with the mass concentration are adopted to prepare the etching liquid according to the volume ratio. Specifically, the silicon substrate can be placed in an etching liquid tank containing hydrofluoric acid and hydrogen peroxide. S11, the nanometer metal particles deposited on the surface of the silicon substrate are used as a cathode, the silicon is used as an anode, a micro electrochemical reaction channel is formed on the surface of the silicon substrate, hydrogen peroxide and hydrofluoric acid are jointly used as etching liquid, the hydrogen peroxide acts on the silicon to generate silicon dioxide, the hydrofluoric acid complexes the silicon dioxide to generate a water-soluble complex, so that a micro-nano hole structure is quickly etched below the nanometer metal particles, the opening shape of the formed micro-nano hole is related to the crystal direction due to etching anisotropy, a quadrilateral micro-nano hole is generally formed in the crystal direction (100), a hexagonal micro-nano hole is generally formed in the crystal direction (111), and the like.
Since the etching action of the etching liquid on silicon in the same crystal orientation is substantially the same except for the crystal boundaries, the shape, width (distance between two parallel sides of a quadrangle or hexagon), and depth of the hole in the same crystal orientation are substantially the same. The size and depth of the opening can be controlled by adjusting the concentration, temperature or time of the etching liquid for different crystal orientations. The invention adopts the volume of hydrogen peroxide: volume of hydrofluoric acid: volume of water is (2-5): 1: (5-8), further preferably selecting the volume of hydrogen peroxide: volume of hydrofluoric acid: volume of water is (3-5): 1: (5-8) so as to prepare the substrate holes with unique size and depth. Further preferably, the reaction temperature is 30-40 ℃, and the etching time is 200-300 s. Due to the appropriate holes, the difficulty increase of the subsequent battery process can be avoided, the light trapping effect is avoided, and the efficiency of the battery piece is optimized. Generally, after the hole is opened, the silicon substrate is washed by deionized water for 120-240 s.
S31, micro-nano hole cutting and expanding: putting the silicon substrate obtained in the step S21 into a mixed acid liquid containing nitric acid and hydrofluoric acid, wherein the volume of the nitric acid in the mixed acid liquid is as follows: volume of hydrofluoric acid: the volume of water is (5.0-9.0) and (7-10) is 1; in the step S31, the mass concentration of the nitric acid is 65-68%; the mass concentration of the hydrofluoric acid is 49-50%; namely, the mixed acid liquid is prepared by adopting the nitric acid and the hydrofluoric acid with the mass concentration according to the volume ratio. Specifically, the silicon substrate is placed in a mixed acid solution containing nitric acid and hydrofluoric acid, micro-nano holes formed by etching the surface of the silicon substrate are jointly etched by the nitric acid and the hydrofluoric acid, the micro-nano holes are etched by the mixed acid solution with high concentration and high nitric acid content, the hole depth of the micro-nano holes can be reduced, meanwhile, the micro-nano holes are further optimized, the opening shapes and sizes of the micro-nano holes are optimized, and the mixed acid liquid with high concentration and high nitric acid content is unexpectedly found to passivate the original quadrilateral or hexagonal edges to form arc angles, so that the openings of the micro-nano holes are changed from the original quadrilateral or hexagonal to a quasi-circular shape (the quasi-circular shape of the invention is similar to a circular shape, only the edges are etched into circular arcs because the edges of the original polygon are not etched, and the width of the quasi-circular shape refers to the radial width passing through the central point), and meanwhile, the micro-nano holes can be further reamed. Because the depth of the micro-nano holes is deep, the mixed acid solution needs a certain time to enter the holes, the outer surface edges and the wall surfaces of the micro-nano holes are etched preferentially, and under a high-concentration and high-nitric-acid-rich mixed acid solution system, the etching solution has a high etching speed on a silicon substrate, so that the remaining micro-nano holes (on which a layer of micro-nano holes has been cut) are etched to form quasi-circular truncated cone-shaped micro-nano holes with wide outside and narrow inside and inverted trumpet shape (observed from the outside to the inside of the silicon surface), as shown in fig. 3.
The volume of nitric acid is preferably selected, the volume of hydrofluoric acid is preferably selected, the volume of water is (6.0-8.0): 1, (8-9), a hole structure with a specific shape is prepared by adopting a mixed acid solution containing specific concentrations of nitric acid and hydrofluoric acid, the concentration ratio gamma of nitric acid to hydrofluoric acid is preferably 5-9, and more preferably 6-8, under the same total acid concentration, if gamma is small, the reaction speed is slow, the etching speed of the top and the bottom of the micropore is close, namely, a hole with an inverted horn shape cannot be formed, at the moment, the included angle α between the inclined surface and the bottom surface of the hole is 90 degrees or close to 90 degrees (α is α degrees, namely, the micro-nano hole is a quasi-cylindrical hole), as shown in fig. 5, the larger gamma is, the reaction speed is higher, the difference between the width d1 of the top surface (opening) and the width d2 of the quasi-cylindrical micro-nano-hole is larger, the included angle α of the hole is larger, the amount of holes reflected after light incidence is more, the reflectivity is also larger, the advantage of the light trap hole is not easily lost, and otherwise, the light trap effect is not too large.
Preferably, the reaction temperature in the step is 8-13 ℃, the optimal temperature is 9-11 ℃, the reaction time is 80-180 s, and the optimal time is 100-150 s. The micro-nano pore structure is further optimized, the phenomena of average reflectivity increase and crystal flower generation are avoided, and the process is simplified. Preferably, the weight reduction amount of the single silicon substrate before and after the working procedure is controlled to be 0.06-0.15 g, the optimal range is 0.08-0.12 g, and the performance of the solar cell piece is further optimized.
Generally, after micro-nano holes are cut and expanded, the silicon substrate is washed by deionized water for 120-240 s.
S41, removing porous silicon and correcting micro-nano holes: and (5) placing the silicon substrate obtained in the step (S31) in alkali liquor to remove the porous silicon layer and correct the micro-nano holes. Preferably, the alkali liquor is a sodium hydroxide or potassium hydroxide solution with the mass concentration of 0.2-5.0%, and the time for placing the alkali liquor in the alkali liquor is 5.0-30 s. Specifically, the silicon substrate is placed in a groove containing sodium hydroxide or potassium hydroxide solution for etching, and the loose porous silicon structure on the outer surface layer of the silicon is quickly removed by low-concentration strong alkali, so that the suede formed by the quasi-circular truncated cone-shaped micro-nano holes with the characteristics of the invention is exposed. Preferably, the reaction temperature is normal temperature, the reaction time is 5.0-30 s, the micro-nano holes cut and expanded in the step cannot be damaged, and the shape and the volume cannot be changed greatly. Generally, after the reaction is finished, the silicon substrate is washed by deionized water for 120-240 s.
And S51, removing the metal particles. It is preferable that the silicon substrate obtained in step S41 is placed in a solution containing aqueous ammonia and hydrogen peroxide. Specifically, the silicon substrate obtained in the step S41 may be placed in a mixed liquid tank containing ammonia water and hydrogen peroxide, where the volume of the ammonia water is: volume of hydrogen peroxide: volume of water 1: (1-4): (40-50); in the step S41, the mass concentration of the ammonia water is 25-28%, and the mass concentration of the hydrogen peroxide is 30-32%; the ammonia water and hydrogen peroxide with the mass concentration are adopted to prepare mixed liquid according to the volume, the hydrogen peroxide is used as an oxidant, nano metal (such as silver) particles which are not removed in the previous cleaning are oxidized, and the ammonia water is used as a complexing agent to form silver amine complex ions which are dissolved in water and are removed. Preferably, the reaction temperature is normal temperature, the reaction time is 50-300 s, and generally, the silicon substrate can be washed by deionized water for 120-240 s after the reaction is finished.
The step S51 is followed by:
and S52, washing with mixed acid. Specifically, the silicon substrate obtained in step S51 may be placed in an acid solution containing hydrofluoric acid and hydrochloric acid to be washed to remove other trace metal impurities (such as metal impurities including iron, nickel, etc.), and the material volume fraction ratio in the acid solution containing hydrofluoric acid and hydrochloric acid is hydrochloric acid: hydrofluoric acid: water (2-3): 1: (5-6), in the step S52, the mass concentration of the hydrochloric acid is 35-38%, and the mass concentration of the hydrofluoric acid is 49-50%. Preferably, the reaction temperature is normal temperature, and the cleaning time is 50-300 s. After the reaction, the silicon substrate may be washed with deionized water for 120-240 s.
And S53, slowly pulling. Specifically, the silicon substrate obtained in the step S52 may be cleaned with hot deionized water at a temperature of 60 to 80 ℃ for 120 to 240 seconds, and then slowly pulled to lift the silicon substrate out of the water. The pulling time is 5-20 s. The residual ion concentration of water in the tank can be controlled, the resistance value of deionized water in the tank is tested by a conductivity meter, and the conductivity value is controlled to be less than or equal to 1.0 mu S/cm at 70 +/-2 ℃.
And S54, drying, specifically, drying the silicon substrate obtained in the step S53 in a hot drying mode at the drying temperature of 100-150 ℃ for 5-15 min.
Preferably, the concentration of metal atoms or ions on the surface of the silicon substrate obtained after drying is less than or equal to 50ppb, and an inductively coupled plasma mass spectrometer (ICP-MS) is used for testing. The silicon substrate with the special structure of the invention has less residual nano metal particles due to the holes of the substrate with the special structure on the surface, eliminates the recombination center of current carriers and can improve the photoelectric conversion efficiency.
After the steps are specifically implemented, the silicon substrate subjected to texturing on the diamond wire cutting silicon substrate is obtained, as can be seen from fig. 7, texturing on the surface of the silicon substrate is uniform, no crystal boundary phenomenon exists, and the average light reflectivity of the silicon substrate is 14-22%, preferably 16-20% within a wave band of 400-1100 nm through detection of a textured reflectivity instrument. When the texture of the silicon substrate prepared by the invention is observed under a Scanning Electron Microscope (SEM), the texture is formed by micro-nano holes with certain opening width, inclination angle and hole depth.
And S61, diffusion. Diffusion process the present invention is not limited and various diffusion processes known to those skilled in the art may be employed and will not be described herein. After the silicon substrate with the texture surface is prepared, the silicon substrate enters a diffusion furnace to prepare PN junctions through phosphorus diffusion, and the diffusion process is approximately the same as that of a mortar silicon slice subjected to conventional acid texturing. Because the quasi-circular truncated-cone-shaped micro-nano hole has the inverted-trumpet-shaped structure, phosphorus source gas is easy to diffuse and covers the wall surface and the bottom of the hole in the diffusion process, so that the N-type diffusion layer is uniformly distributed along the hole, the effect of collecting carriers by the N layer is good, and the open-circuit voltage and the short-circuit current of the battery are high. In the invention, the diffusion temperature or the phosphorus source amount is adjusted, so that the average sheet resistance of the diffused silicon wafer is 80-100 omega/□, and the optimal sheet resistance is 85-90 omega/□, and the sheet resistance range has better matching degree with the texture surface characterized by the invention.
Preferably, after step S61, the method further includes:
s62, removing phosphorus silicon glass. The phosphorosilicate glass is generally removed by secondary cleaning, the phosphorosilicate glass layer is removed, and the periphery of the silicon substrate is etched.
And S71, plating an antireflection film. PECVD SiN platingxAn antireflection film. The coating process is not limited by the invention, and the field can be adoptedVarious coating processes known to the skilled person are not described in detail herein. The substrate hole with the special structure prepared by the method enables silane gas and ammonia gas to smoothly enter the hole, so that atomic hydrogen has a good passivation effect on the hole wall and the bottom in the film coating process, dangling bonds generated by silicon in the hole in the etching texturing process are greatly reduced, the number of recombination centers is reduced, the open-circuit voltage and the short-circuit current of the battery are improved to a certain extent, and preferably, the thickness of an antireflection film layer is 80-90 nm, and the average refractive index is 2.00-2.20.
And S81, preparing the solar cell electrode. Generally, the electrodes are printed and metallized to form a light receiving surface electrode and a backlight surface electrode for extracting current, and the light receiving surface electrode and the backlight surface electrode can adopt various electrode structures, for example, a back aluminum paste and a back silver paste can be printed on the back surface, a front silver paste can be printed on the front surface, and after the front silver paste passes through a sintering furnace, a solar cell with a positive electrode and a negative electrode is obtained.
The invention also provides a solar cell which comprises the solar cell piece. Other structures of solar cells are known and will not be described in detail herein.
In order to make the technical problems, technical solutions and advantageous effects solved by the present invention more apparent, the present invention is further described in detail below with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Example 1
The raw material grades and concentrations adopted in the embodiment are respectively as follows: potassium hydroxide, electronic grade, mass concentration 45%; nitric acid: electronic grade, mass concentration of 65-68%, hydrofluoric acid: an electronic grade, wherein the mass concentration is 49-50%; silver nitrate: analytically pure, solid, purity 99.9%; ammonia water: an electronic grade, wherein the mass concentration is 25-28%; hydrogen peroxide and an electronic grade, wherein the mass concentration is 30-32%; hydrochloric acid: an electronic grade, wherein the mass concentration is 35-38%;
the 156 x 156 polycrystalline silicon wafer cut by diamond wires is tested to have the resistivity value range of 1.20-2.50 omega cm, and meets the resistivity requirement of the silicon wafer. The minority carrier lifetime value range is 1.10-1.60 mu s, and the minority carrier lifetime requirement of the silicon wafer is met. The experiment is carried out by adopting 200 pieces (2 flower baskets, 100 pieces in each basket) each time, the experimental result is averaged, and the volume of each process tank is about 120 liters. The whole texturing process comprises the following process steps:
a (initial alkali polishing): adding 15L of potassium hydroxide solution into the primary polishing groove, adding 105L of water to obtain 7.83% of potassium hydroxide solution, heating the solution to 80 ℃, and putting the silicon wafer into the solution, wherein the etching time is 4.0 min. And after the etching is finished, the silicon wafer is washed for 150s away from water, and the polycrystalline silicon wafer without greasy dirt and damage layers is obtained. The weight loss in this step was measured by an electronic scale to be 0.282 g/piece.
B (acid wash): and (3) putting the silicon wafer in the step (1) into a cleaning tank, wherein the cleaning solution in the tank is diluted nitric acid with the volume concentration of 1%, the cleaning time is 2min, and the silicon wafer is cleaned for 150s away from water.
C (deposit metal particles): and (3) putting the silicon wafer in the step into a metal particle deposition tank, adding 4L of hydrofluoric acid and 116L of water into the metal particle deposition tank, adding 4g of silver nitrate crystal to obtain the silver nitrate with the concentration of 33.4ppm, heating the solution in the tank to 20 +/-1 ℃, and reacting for 60 s. After the reaction was complete, the wafer was washed away from water for 10s to remove floating silver particles.
D (forming micro-nano holes), namely placing the silicon wafer in the step A into a hole forming groove, and adding 10L of hydrofluoric acid, 40L of hydrogen peroxide, 70L of deionized water and the volume of hydrogen peroxide: volume of hydrofluoric acid: volume of water 4:1: 7; the temperature was raised to 35 ℃ for 240s and after the reaction was complete, the wafer was rinsed away from water for 150 s.
E (micro-nano hole cutting and expanding): placing the silicon wafer in the step into a micro-nano hole cutting and expanding groove, wherein the volume ratio of nitric acid to hydrofluoric acid in the groove is nitric acid: hydrofluoric acid: and (3) weighing the weight loss of the step by using an electronic scale to be 0.103 g/piece, wherein the water is 7:1:9, the temperature of the mixed acid solution is 10 ℃, the reaction time is 120 seconds, the silicon wafer is taken out after the reaction is finished, and the silicon wafer is washed away from water for 150 seconds.
F (porous silicon removal and micro-nano hole correction): and (3) putting the silicon wafer in the step into a tank with sodium hydroxide added for correction reaction, wherein the mass concentration of the sodium hydroxide is 2.0%. The reaction temperature is 20 ℃, the reaction time is 15s, and after the reaction is finished, the silicon wafer is washed away from water for 150 s.
G (removal of metal particles): and (3) putting the silicon wafer in the step into a mixed liquid tank added with ammonia water and hydrogen peroxide for cleaning nano silver particles, wherein the volume concentration of the ammonia water in the tank is 3%, and the volume concentration of the hydrogen peroxide in the tank is 5%. The temperature of the solution was 20 c and the cleaning time was 200 seconds, after which the wafer was washed away from water for 150 seconds.
H (mixed acid wash): and (3) cleaning the silicon wafer in the previous step in a mixed acid solution of hydrofluoric acid and hydrochloric acid, wherein the volume concentration of the hydrofluoric acid in the mixed solution is 10%, the volume concentration of the hydrochloric acid is 20%, the temperature of the solution is 20 ℃, the pickling time is 200s, and then cleaning the silicon wafer in water for 150 s.
I (slow pull): and cleaning the silicon wafer cleaned in the previous step by hot deionized water for 150S, wherein the temperature of the water is 70 ℃, then slowly lifting, lifting the silicon wafer out of the water surface for 10S, and testing the conductivity value of the deionized water in the tank at 69 ℃ to be 0.50-0.70 mu S/cm by using a conductivity meter.
J (dry): and (3) drying the silicon wafer cleaned in the previous step by using heat, wherein the drying temperature is 120 ℃, and the drying time is 10 min.
After the above steps were performed, the silicon substrate 1 sample SA1 obtained in this example was obtained, and SA1 was observed by Scanning Electron Microscope (SEM) at 50000 times magnification, and the result is shown in FIG. 3. The appearance of the SA1 is shown in fig. 7.
The surface was tested for a residual silver particle concentration of 17.30PPb using an ICP-MS instrument.
K (diffusion): and (3) putting the silicon substrate 1 sample SA1 dried in the step into a diffusion furnace, and preparing a PN junction through phosphorus diffusion.
L (dephosphorized silicate glass): and (4) carrying out secondary cleaning on the silicon wafer subjected to diffusion in the previous step to etch and remove the phosphorosilicate glass and the peripheral diffusion layer.
M (plating an antireflection film), cleaning the silicon wafer diffused in the previous step twice, and then carrying out PECVD (plasma enhanced chemical vapor deposition) SiN platingxAnd the antireflection film has an average thickness of 82nm and an average refractive index of 2.10.
N (preparation of solar cell electrode): printing back aluminum paste and back silver paste on the back surface of the silicon wafer coated by the film in the previous step, printing front silver paste on the front surface of the silicon wafer, and performing a sintering furnace to obtain a polycrystalline silicon solar cell sample SS1 of the invention, as shown in FIG. 2, the prepared solar cell comprises a silicon substrate 1, and a diffusion layer 2 and an antireflection film layer 3 attached to the surface of the silicon substrate 1, wherein the surface of the silicon substrate 1 is provided with a substrate hole 4, the diffusion layer 2 and the antireflection film layer 3 located at the substrate hole 4 are attached to the side surface and the bottom surface, namely the hole wall and the bottom of the substrate hole 4 to form a cell hole 5, and in the embodiment, a hydrogen passivation layer 6 is formed on the surface of the diffusion layer 2 in the antireflection film coating process, namely, the diffusion layer 2 and the antireflection film layer.
SS1 was observed by scanning electron microscope at 20000 times, and the results are shown in FIG. 4. The appearance of SS1 is shown in fig. 10.
Example 2
A solar cell sample SS2 was prepared using the same method steps as in example 1, except that the substance volume ratio of nitric acid and hydrofluoric acid in step E (micro-nano hole shaving) was changed to nitric acid: hydrofluoric acid: water 5:1:10, a silicon substrate sample SA2 was prepared.
Example 3
A solar cell sample SS3 was prepared using the same method steps as in example 1, except that the substance volume ratio of nitric acid and hydrofluoric acid in step E (micro-nano hole shaving) was changed to nitric acid: hydrofluoric acid: water 9:1:9, a silicon substrate sample SA3 was prepared.
Example 4
A solar cell sample SS4 was prepared using the same method steps as in example 1, except that the substance volume ratio of nitric acid and hydrofluoric acid in step E (micro-nano hole shaving) was changed to nitric acid: hydrofluoric acid: water 8:1:7, a silicon substrate sample SA4 was prepared.
Example 5
A solar cell sample SS5 was prepared using the same method steps as in example 1, except that the reaction time of step E (micro-nano hole reaming) was 150s, and a silicon substrate sample SA5 was prepared.
Example 6
A solar cell sample SS6 was prepared using the same method steps as in example 1, except that the volume of hydrogen peroxide in step D (micro-nano hole opening): volume of hydrofluoric acid: volume of water 3: 1: 8, a silicon substrate sample SA6 was prepared.
Comparative example 1
A solar cell sample DSS1 was prepared using the same method steps as in example 1, except that the substance volume ratio of nitric acid to hydrofluoric acid in step E (micro-nano hole shaving) was changed to nitric acid: hydrofluoric acid: a silicon substrate sample DSA1 was prepared with water at 4:1:10, and DSA1 was observed by scanning electron microscopy at 50000 magnifications, the results are shown in fig. 5. The appearance of DSA1 is as in fig. 8. The appearance of DSS1 is as in fig. 11.
Comparative example 2
A solar cell sample DSS2 was prepared according to the same method steps as in example 1, except that the reaction time of step E (micro-nano hole reaming) was 200s, and a silicon substrate sample DSA2 was prepared.
Comparative example 3
A solar cell sample DSS3 was prepared using the same method steps as in example 1, except that the volume of hydrogen peroxide in step D (micro-nano hole opening): volume of hydrofluoric acid: volume of water 6: 1:7, a silicon substrate sample DSA3 was prepared.
Comparative example 4
Preparing a polycrystalline silicon suede (namely a one-step cleaning process) on a Rena chain machine by adopting a mortar-cut 156X 156 polycrystalline silicon wafer and adopting a traditional mixed acid to obtain a silicon substrate sample DSA4, observing DSA4 by adopting a scanning electron microscope, and amplifying by 10000 times, wherein the result is shown in an attached figure 6; the appearance of DSA4 is as in fig. 9; a solar cell sample DSS4 was obtained through the same procedures as those for preparing K (diffusion), L (dephosphorized silica glass), M (plating antireflection film) and N (preparing solar cell electrodes) in example 1. The appearance of DSS4 is as in fig. 12.
Performance testing
The silicon substrates SA1-SA6 and DSA1-DSA4 are characterized in that micro-nano holes of the silicon substrates SA1-SA6 and DSA1-DSA4 are observed and tested under a Scanning Electron Microscope (SEM), and the shape parameters of the micro-nano holes comprise the width of an opening on the top surface (d1, unit: nm), the included angle between the side surface and the bottom surface (α, unit: degree) and the depth (h, unit: nm), and the prepared silicon substrates are detected by a suede reflectivity meterAverage light reflectance within a wavelength range of 400 to 1100 nm: (
Unit: %).
The electrical performance parameters of the battery piece are as follows: and testing by using a special testing instrument for the solar cell, such as a single flash simulator. Test conditions were Standard Test Conditions (STC): light intensity: 1000W/m2(ii) a Spectrum: 1.5 of AM; temperature: 25. the test method was carried out according to IEC 904-1. The main electrical property parameters of the battery piece are as follows: photoelectric conversion efficiency (Eta, unit:%), short-circuit current (Isc, unit: A), open-circuit voltage (Voc, unit: V), (fill factor (FF, unit:%), leakage current (IRev)2The unit: A) series resistance (Rs, unit: m Ω), parallel resistance (Rsh, unit: Ω).
The results of the silicon substrate characterization parameter test are shown in table 1:
TABLE 1
The results of the cell electrical property parameter tests are shown in table 2.
TABLE 2
| Sample (I) | Eta | Isc | Voc | FF | IRev2 | Rs | Rsh |
| SS1 | 19.08 | 9.1055 | 0.6324 | 80.74 | 0.3098 | 0.00105 | 556.673 |
| SS2 | 18.85 | 8.9481 | 0.6318 | 80.51 | 0.2753 | 0.00119 | 414.774 |
| SS3 | 18.90 | 8.9842 | 0.6317 | 80.76 | 0.3267 | 0.00110 | 573.820 |
| SS4 | 18.97 | 8.9991 | 0.6315 | 80.57 | 0.2750 | 0.00109 | 402.778 |
| SS5 | 18.92 | 8.9671 | 0.6316 | 80.72 | 0.3067 | 0.00121 | 512.820 |
| SS6 | 18.80 | 8.9521 | 0.6319 | 80.65 | 0.4821 | 0.00110 | 237.000 |
| DSS1 | 18.49 | 8.8425 | 0.6305 | 80.70 | 0.5479 | 0.00130 | 386.774 |
| DSS2 | 18.56 | 8.8372 | 0.6319 | 80.87 | 0.3336 | 0.00114 | 277.572 |
| DSS3 | 18.27 | 8.7574 | 0.6293 | 80.68 | 0.3478 | 0.00094 | 229.732 |
| DSS4 | 18.44 | 8.7821 | 0.6311 | 80.73 | 0.4370 | 0.00180 | 299.042 |
As can be seen from the results in table 2, the short-circuit current of the battery cell prepared in the embodiment of the present invention is greatly improved, all over 150mA, and the open-circuit voltage is also improved within a certain range, compared with the conventional mortar cell (comparative example DSS4), so that the conversion efficiency of the battery cell is significantly improved, all over 0.30%. The battery plate prepared by the comparative example has lower efficiency, and the open-circuit voltage of the battery plate without the battery plate hole with the special structure of the invention is obviously reduced (for example, the open-circuit voltage of DSS3 is reduced by more than 3 mV).
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included therein.
It will be understood by those skilled in the art that the foregoing is merely exemplary of the present invention, and is not intended to limit the invention to the particular forms disclosed herein, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. The scope of the invention is defined by the claims.
Claims (7)
1. A preparation method of a solar cell is characterized by comprising the following steps: forming a substrate hole with an opening width of 500-1200 nm and a depth of 200-500 nm on the surface of a silicon substrate, and then diffusing and attaching an antireflection film to obtain a solar cell;
the method comprises the following steps: s11, depositing metal particles: placing the silicon substrate in a mixed solution containing metal ion salt and hydrofluoric acid to deposit metal particles;
s21, forming micro-nano holes: placing the silicon substrate obtained in the step S11 in an etching solution containing hydrofluoric acid and hydrogen peroxide for etching; the volume of hydrogen peroxide in the etching liquid is as follows: volume of hydrofluoric acid: volume of water is (2-5): 1: (5-8); in the step S21, the mass concentration of the hydrogen peroxide is 30-32%; the mass concentration of the hydrofluoric acid is 49-50%;
s31, micro-nano hole cutting and expanding: putting the silicon substrate obtained in the step S21 into a mixed acid liquid containing nitric acid and hydrofluoric acid, wherein the volume of the nitric acid in the mixed acid liquid is as follows: volume of hydrofluoric acid: the volume of water is (5.0-9.0) and (7-10) is 1; in the step S31, the mass concentration of the nitric acid is 65-68%; the mass concentration of the hydrofluoric acid is 49-50%;
s41, removing porous silicon and correcting micro-nano holes: placing the silicon substrate obtained in the step S31 in alkali liquor to remove the porous silicon layer and correct the micro-nano holes;
s51, removing metal particles;
s61, diffusion;
s71, plating an antireflection film;
s81, preparing a solar cell electrode;
and (5) preparing the solar cell.
2. The preparation method of the solar cell piece according to claim 1, wherein the etching time in the step S21 is 200-300S.
3. The method for manufacturing a solar cell according to claim 1, wherein the volume of nitric acid in the mixed acid solution in step S31 is: volume of hydrofluoric acid: the volume of the water is (6.0-8.0) and (8-9) respectively.
4. The method for preparing the solar cell piece according to claim 1, wherein the step S31 is carried out in the mixed acid solution for 80-180S, and the temperature of the mixed acid solution is 8-13 ℃.
5. The method for preparing the solar cell piece according to claim 1, wherein the alkali solution in the step S41 is a sodium hydroxide or potassium hydroxide solution with a mass concentration of 0.2-5.0%, and the time for placing the alkali solution in the alkali solution is 5.0-30S.
6. The method of claim 1, wherein the concentration of the metal ions in the mixed solution of the salt containing the metal ions and the hydrofluoric acid in step S11 is 10-100 ppm, and the volume concentration of the hydrofluoric acid in the mixed solution is 0.5-10%; wherein the mass concentration of the hydrofluoric acid is 49-50%;
the step S51 of removing metal particles is to put the silicon substrate obtained in the step S41 into a solution containing ammonia and hydrogen peroxide.
7. The method for preparing the solar cell piece according to claim 1, wherein the step S11 is preceded by the steps of pre-treating a silicon substrate:
s01, primary alkali polishing;
s02, acid cleaning;
the step S51 is followed by:
s52, mixed acid cleaning;
s53, slowly pulling;
s54, drying;
the step S61 is followed by:
s62, removing phosphorus silicon glass.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710111365.5A CN108511539B (en) | 2017-02-28 | 2017-02-28 | Preparation method of solar cell |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710111365.5A CN108511539B (en) | 2017-02-28 | 2017-02-28 | Preparation method of solar cell |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108511539A CN108511539A (en) | 2018-09-07 |
| CN108511539B true CN108511539B (en) | 2020-02-04 |
Family
ID=63373141
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710111365.5A Active CN108511539B (en) | 2017-02-28 | 2017-02-28 | Preparation method of solar cell |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108511539B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109461791B (en) * | 2018-10-24 | 2020-08-25 | 盐城阿特斯协鑫阳光电力科技有限公司 | Texturing method of monocrystalline silicon wafer |
| CN112103278B (en) * | 2020-08-06 | 2021-05-11 | 常熟理工学院 | Silicon-based laminated solar cell with microstructure and preparation method thereof |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104393114A (en) * | 2014-11-17 | 2015-03-04 | 中国电子科技集团公司第四十八研究所 | Preparation method of polycrystalline black silicon of micro-nano composite suede structure |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012099953A1 (en) * | 2011-01-18 | 2012-07-26 | Bandgap Engineering, Inc. | Method of electrically contacting nanowire arrays |
| CN103219428B (en) * | 2013-04-12 | 2015-08-19 | 苏州大学 | Suede structure of a kind of crystal silicon solar energy battery and preparation method thereof |
| FR3038143B1 (en) * | 2015-06-26 | 2017-07-21 | Commissariat Energie Atomique | METHOD OF ISOLATING THE EDGES OF A HETEROJUNCTION PHOTOVOLTAIC CELL |
| CN105047734A (en) * | 2015-08-27 | 2015-11-11 | 江苏辉伦太阳能科技有限公司 | Inverted pyramid structure of polysilicon surface and fabrication method of inverted pyramid structure |
| CN105070792B (en) * | 2015-08-31 | 2018-06-05 | 南京航空航天大学 | A kind of preparation method of the polycrystalline solar cell based on solwution method |
| CN106057972A (en) * | 2016-06-27 | 2016-10-26 | 苏州阿特斯阳光电力科技有限公司 | Preparation method of crystalline silicon solar cell textured structure |
-
2017
- 2017-02-28 CN CN201710111365.5A patent/CN108511539B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104393114A (en) * | 2014-11-17 | 2015-03-04 | 中国电子科技集团公司第四十八研究所 | Preparation method of polycrystalline black silicon of micro-nano composite suede structure |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108511539A (en) | 2018-09-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Kim et al. | Texturing of large area multi-crystalline silicon wafers through different chemical approaches for solar cell fabrication | |
| Chen et al. | MACE nano-texture process applicable for both single-and multi-crystalline diamond-wire sawn Si solar cells | |
| US8815104B2 (en) | Copper-assisted, anti-reflection etching of silicon surfaces | |
| CN106229386B (en) | A kind of method that silver-bearing copper bimetallic MACE method prepares black silicon structure | |
| EP3780121A1 (en) | Copper-assisted, anti-reflection etching of silicon surfaces | |
| CN103066160B (en) | A kind of method of solar cell silicon wafer Surface Creation porous silicon | |
| Wang et al. | 18.88%-efficient multi-crystalline silicon solar cells by combining Cu-catalyzed chemical etching and post-treatment process | |
| CN108365023A (en) | Coating process for the black silicon face passivation of polycrystalline | |
| CN108511539B (en) | Preparation method of solar cell | |
| CN105133038B (en) | The preparation method and applications of polysilicon with efficient nano suede structure | |
| CN104966762A (en) | Preparation method of texturized surface structure of crystalline silicon solar cell | |
| Zhang et al. | An 18.9% efficient black silicon solar cell achieved through control of pretreatment of Ag/Cu MACE | |
| Sreejith et al. | A low cost additive-free acid texturing process for large area commercial diamond-wire-sawn multicrystalline silicon solar cells | |
| Tong et al. | Influence of surface structure on the performance of mono-like Si PERC solar cell | |
| CN110518075B (en) | Black silicon passivation film, and preparation method and application thereof | |
| CN107611226A (en) | A kind of crystalline silicon method for manufacturing textured surface, solar cell and preparation method thereof | |
| CN110518080B (en) | Reworking method of acid texturing polycrystalline battery | |
| CN109671802A (en) | A kind of back passivation efficient polycrystalline silicon PERC double-side cell technique | |
| CN112701184A (en) | Method for manufacturing textured surface of crystalline silicon battery | |
| Park et al. | 25-cm2 glass-like transparent crystalline silicon solar cells with an efficiency of 14.5% | |
| CN110872729B (en) | Texturing and hole digging additive, texturing and silver sinking hole digging liquid, silicon wafer and solar cell of diamond wire cutting polycrystalline silicon wafer | |
| CN104409564B (en) | N-type nanometer black silicon manufacturing method and solar cell manufacturing method | |
| CN106057972A (en) | Preparation method of crystalline silicon solar cell textured structure | |
| CN105839192A (en) | Wet texturization method for pretreated silicon wafer | |
| Sreejith et al. | Optimization of MACE black silicon surface morphology in multi-crystalline wafers for excellent opto-electronic properties |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |