KR101733438B1 - Compositionally graded CZTSSe thin film and its preparation method - Google Patents
Compositionally graded CZTSSe thin film and its preparation method Download PDFInfo
- Publication number
- KR101733438B1 KR101733438B1 KR1020150020601A KR20150020601A KR101733438B1 KR 101733438 B1 KR101733438 B1 KR 101733438B1 KR 1020150020601 A KR1020150020601 A KR 1020150020601A KR 20150020601 A KR20150020601 A KR 20150020601A KR 101733438 B1 KR101733438 B1 KR 101733438B1
- Authority
- KR
- South Korea
- Prior art keywords
- thin film
- znsn
- solar cell
- selenium
- sulfur
- Prior art date
Links
- 239000010409 thin film Substances 0.000 title claims abstract description 88
- 238000002360 preparation method Methods 0.000 title description 2
- 239000011669 selenium Substances 0.000 claims abstract description 141
- 229910052711 selenium Inorganic materials 0.000 claims abstract description 104
- 229910052717 sulfur Inorganic materials 0.000 claims abstract description 94
- 239000000203 mixture Substances 0.000 claims abstract description 49
- BUGBHKTXTAQXES-UHFFFAOYSA-N Selenium Chemical compound [Se] BUGBHKTXTAQXES-UHFFFAOYSA-N 0.000 claims abstract description 47
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 claims abstract description 34
- 238000000034 method Methods 0.000 claims abstract description 34
- 239000011593 sulfur Substances 0.000 claims abstract description 29
- 239000012298 atmosphere Substances 0.000 claims abstract description 8
- 229910045601 alloy Inorganic materials 0.000 claims abstract description 6
- 239000000956 alloy Substances 0.000 claims abstract description 6
- 229910007610 Zn—Sn Inorganic materials 0.000 claims abstract description 4
- 238000010438 heat treatment Methods 0.000 claims description 35
- 238000004519 manufacturing process Methods 0.000 claims description 16
- 239000007789 gas Substances 0.000 claims description 15
- 239000000758 substrate Substances 0.000 claims description 13
- 230000008016 vaporization Effects 0.000 claims description 13
- 238000009834 vaporization Methods 0.000 claims description 12
- 239000010408 film Substances 0.000 claims description 10
- 239000012159 carrier gas Substances 0.000 claims description 8
- 229910001092 metal group alloy Inorganic materials 0.000 claims description 7
- 238000001816 cooling Methods 0.000 claims description 6
- 230000008018 melting Effects 0.000 claims description 6
- 238000002844 melting Methods 0.000 claims description 6
- 239000000843 powder Substances 0.000 claims description 6
- 230000008569 process Effects 0.000 abstract description 14
- 238000002441 X-ray diffraction Methods 0.000 abstract description 6
- 238000007740 vapor deposition Methods 0.000 abstract description 5
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 abstract description 4
- 238000004070 electrodeposition Methods 0.000 abstract description 4
- 230000015572 biosynthetic process Effects 0.000 abstract description 3
- 229910052750 molybdenum Inorganic materials 0.000 abstract description 3
- PDYXSJSAMVACOH-UHFFFAOYSA-N [Cu].[Zn].[Sn] Chemical compound [Cu].[Zn].[Sn] PDYXSJSAMVACOH-UHFFFAOYSA-N 0.000 abstract description 2
- 229910052786 argon Inorganic materials 0.000 abstract description 2
- 238000006243 chemical reaction Methods 0.000 abstract description 2
- 239000005361 soda-lime glass Substances 0.000 abstract description 2
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 abstract 1
- 238000000137 annealing Methods 0.000 abstract 1
- 238000001941 electron spectroscopy Methods 0.000 abstract 1
- 239000011733 molybdenum Substances 0.000 abstract 1
- 238000005580 one pot reaction Methods 0.000 abstract 1
- 239000010949 copper Substances 0.000 description 20
- 238000002149 energy-dispersive X-ray emission spectroscopy Methods 0.000 description 13
- OAKJQQAXSVQMHS-UHFFFAOYSA-N Hydrazine Chemical compound NN OAKJQQAXSVQMHS-UHFFFAOYSA-N 0.000 description 8
- 125000004434 sulfur atom Chemical group 0.000 description 8
- 238000005215 recombination Methods 0.000 description 7
- 230000004913 activation Effects 0.000 description 6
- 230000007423 decrease Effects 0.000 description 6
- 230000003247 decreasing effect Effects 0.000 description 6
- 230000006798 recombination Effects 0.000 description 6
- 238000005259 measurement Methods 0.000 description 5
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 125000003748 selenium group Chemical group *[Se]* 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- 229910016001 MoSe Inorganic materials 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 3
- 238000004364 calculation method Methods 0.000 description 3
- 229910052802 copper Inorganic materials 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000006872 improvement Effects 0.000 description 3
- 230000007246 mechanism Effects 0.000 description 3
- 238000011160 research Methods 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 238000000862 absorption spectrum Methods 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 238000000151 deposition Methods 0.000 description 2
- 230000008021 deposition Effects 0.000 description 2
- 238000002524 electron diffraction data Methods 0.000 description 2
- 230000004298 light response Effects 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 239000002243 precursor Substances 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 238000004098 selected area electron diffraction Methods 0.000 description 2
- 238000004611 spectroscopical analysis Methods 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 230000010748 Photoabsorption Effects 0.000 description 1
- 229910001128 Sn alloy Inorganic materials 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- ZQRRBZZVXPVWRB-UHFFFAOYSA-N [S].[Se] Chemical compound [S].[Se] ZQRRBZZVXPVWRB-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 150000001450 anions Chemical class 0.000 description 1
- 239000000969 carrier Substances 0.000 description 1
- 150000004770 chalcogenides Chemical class 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000008139 complexing agent Substances 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 230000006735 deficit Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000010790 dilution Methods 0.000 description 1
- 239000012895 dilution Substances 0.000 description 1
- 239000012153 distilled water Substances 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 238000013213 extrapolation Methods 0.000 description 1
- 238000003475 lamination Methods 0.000 description 1
- 230000031700 light absorption Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000005078 molybdenum compound Substances 0.000 description 1
- 150000002752 molybdenum compounds Chemical class 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000010248 power generation Methods 0.000 description 1
- 238000001552 radio frequency sputter deposition Methods 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 239000001509 sodium citrate Substances 0.000 description 1
- 230000003595 spectral effect Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 229910052718 tin Inorganic materials 0.000 description 1
- 239000011135 tin Substances 0.000 description 1
- -1 tin cations Chemical class 0.000 description 1
- 238000004627 transmission electron microscopy Methods 0.000 description 1
- HRXKRNGNAMMEHJ-UHFFFAOYSA-K trisodium citrate Chemical compound [Na+].[Na+].[Na+].[O-]C(=O)CC(O)(CC([O-])=O)C([O-])=O HRXKRNGNAMMEHJ-UHFFFAOYSA-K 0.000 description 1
- 229940038773 trisodium citrate Drugs 0.000 description 1
- 235000019263 trisodium citrate Nutrition 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 229910052724 xenon Inorganic materials 0.000 description 1
- FHNFHKCVQCLJFQ-UHFFFAOYSA-N xenon atom Chemical compound [Xe] FHNFHKCVQCLJFQ-UHFFFAOYSA-N 0.000 description 1
- 239000011701 zinc Substances 0.000 description 1
- 229910052725 zinc Inorganic materials 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
- H01L31/0248—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 characterised by their semiconductor bodies
- H01L31/036—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 characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes
- H01L31/0392—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 characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes including thin films deposited on metallic or insulating substrates ; characterised by specific substrate materials or substrate features or by the presence of intermediate layers, e.g. barrier layers, on the substrate
-
- 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
- H01L31/02366—Special surface textures of the substrate or of a layer on the substrate, e.g. textured ITO/glass substrate or superstrate, textured polymer layer on glass substrate
-
- 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
- H01L31/0248—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 characterised by their semiconductor bodies
- H01L31/0256—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 characterised by their semiconductor bodies characterised by the material
-
- 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
-
- 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
Abstract
We fabricated a Cu 2 ZnSn (S, Se) 4 (CZTSSe) thin film solar cell with high efficiency of about 10% by electrochemical deposition and subsequent annealing process. A copper-zinc-tin (Cu-Zn-Sn) alloy was formed on soda lime glass on which molybdenum (Mo) was deposited by using one-pot electrochemical vapor deposition, Was annealed in a mixed atmosphere of sulfur (S), selenium (Se) and argon (Ar) to form a CZTSSe thin film having a band gap of 1.13 eV. It was confirmed by X-ray diffraction and electron spectroscopy that a thin film with a high crystallinity of about 2.5 袖 m was successfully formed and a composition / band gap slope in the vertical direction of the CZTSSe thin film in element depth profiling . As a result of bandgap engineering such as adjustment of bandgap energy and formation of bandgap gradients, the optimum CZTSSe thin film solar cell showed a light conversion efficiency of 9.9%. This is the highest efficiency among the CZTSSe thin film solar cells using the electrochemical vapor deposition method so far reported.
Description
The present invention relates to a sloping composition type chalcogenide thin film, a thin film solar cell including the same, and a manufacturing method thereof.
The Cu 2 ZnSn (S, Se) 4 (CZTSSe) thin film is a light absorbing layer of the next generation thin film solar cell and has received considerable research / industrial interest. In particular, CZTSSe is expected to significantly reduce power generation costs due to its abundant constituents, low cost, and high efficiency. Currently, the hydrazine-based solution process shows a maximum efficiency of 12.7%.
Although the hydrazine-based solution process is an inexpensive process as compared with the vacuum process, it is problematic for commercialization and mass production due to the specificity (explosiveness) of hydrazine. In the non-vacuum solution process instead of the hydrazine process, electrochemical vapor deposition is used in several research groups because of its low initial cost of capital, effective utilization of materials, ease of facing, environmental friendliness, and mass production.
Until now, efficiency of CZTSSe thin film solar cell using electrochemical vapor deposition has not been reported more than 8% due to technological difficulties so far.
The present invention relates to a Cu 2 ZnSn (S, Se) 4 (CZTSSe) thin film solar cell and a Cu 2 ZnSn (S, Se) 4 (CZTSSe) thin film solar cell which can be applied thereto by using the electrochemical vapor deposition method and a subsequent heat treatment process. , And a method for producing the same.
One aspect of the present invention is a solar cell-Cu 2 ZnSn (S, Se) 4 thin film, (S s - S v) is a positive number and, (Se s - Se v) is negative, and the S s and S v are each sulfur composition value from the surface and the composition gradient branch point (%), and the Se s and Se v is a solar cell-Cu 2 ZnSn (s, Se), characterized in that the composition value (%) of selenium in each of the surface and the composition gradient of the fork 4 thin film.
In the present invention, a CZTSSe thin film having a band gap of 1.13 eV, which shows a high efficiency of 9.9%, has been successfully achieved by using electrochemical deposition and a subsequent heat treatment process in a mixed selenium-sulfur atmosphere. As compared with the conventional CZTSe having a band gap of 1.02 eV, since the increase of the band gap energy due to the formation of the band gap difference in the vertical direction minimizes the photocurrent reduction and the light voltage and the filling rate are greatly improved, Seems to be.
Figure 1 shows a schematic representation of a heat treatment system.
2 (a) compares X-ray diffraction patterns of CZTSSe (band gap 1.13 eV) and CZTSe (band gap 1.02 eV), which is an enlarged view around the diffraction peak of the 112 plane. FIG. 2 (b) is a cross-sectional clear-sky image using a transmission electron microscope (TEM), and the illustration is a selected area electron diffraction of the corresponding part. Figure 2 (c) shows the results of EDS line scanning.
FIG. 3 shows the horizontal ratio (left side) and the corresponding band gap energy (right side) of the sulfur composition through TEM EDS analysis of the CZTSSe thin film.
4 (a) compares light and dark current-voltage curvature of CZTSSe with CZTSe, and black line means CZTSSe gray line means CZTSe. 4 (b) is an external quantum efficiency (EQE) curve.
FIG. 5 shows (a) Voc-Tplot and (b) admittance spectroscopic characteristics of the temperature dependent characteristics of the CZTSSe thin film solar cell in the 1 sun state.
Hereinafter, various aspects and various embodiments of the present invention will be described in more detail.
One aspect of the present invention is a solar cell-Cu 2 ZnSn (S, Se) 4 thin film, (S s - S v) is a positive number and, (Se s - Se v) is negative, and the S s and S v are each sulfur composition value from the surface and the composition gradient branch point (%), and the Se s and Se v is a solar cell-Cu 2 ZnSn (S, Se), characterized in that the composition value (%) of selenium in each of the surface and the composition gradient of the fork 4 thin film.
In the present invention, the composition gradient point means a point where the composition of sulfur is increasing and the composition of selenium is decreasing from this point to the surface.
According to one embodiment of the present invention, the composition gradient point may be a point at a depth of about 300 to 1,000 nm, preferably 400 to 600 nm at the surface, or may be a specific point in the upper section, depending on the situation Or may be any point within the above section.
For example, in the right-hand elliptical dashed area in Fig. 2c, sulfur decreases from about 30% to about 50% from the surface to about 500 nm (position about 2,700 nm) to the surface (position about 3,200 nm) And selenium decreased from 30% to 25%.
In FIG. 2C, since Mo and S can not be distinguished from each other in the EDS analysis, pink is indicated as a composition of (Mo + S), and there is no possibility that Mo exists in the region from the surface to about 500 nm , And the pink line in the elliptic dotted line area in Fig. 2C may be interpreted as the composition of S.
In one implementation, the larger the value of S / (S + Se) from the surface than the composition gradient of the branch point, the S and Se is a solar cell, characterized in that the elemental composition values (%) of each of sulfur and selenium, Cu 2 ZnSn (S, Se) 4 thin film is disclosed.
In another embodiment, the value of S / (S + Se) from the concentration gradient branch point to the surface is increasing, and S and Se are elemental compositional values (%) of sulfur and selenium, respectively 2 ZnSn (S, Se) 4 thin film is disclosed.
Therefore, in the present invention, as defined above, the composition gradient point means a point where the composition of sulfur is increasing and the composition of selenium is decreasing from this point to the surface, or S / (S + Se) composition ratio may indicate an increasing trend.
In the present invention, the tendency to increase or increase indicates a tendency to increase as a whole although there are some decreasing intervals. Specifically, in FIG. 3, when the position is about 2,750 nm to 3,200 nm, about 2,900 the S / (S + Se) value is increasing at a position of approximately 2,750 nm to 3,200 nm according to the above definition of the present invention, although an extremely narrow region that is partially reduced in the vicinity of nm is observed have.
In yet another embodiment, S / (S + Se) value at the surface is 0.3 to 0.5, and the S and Se is a solar cell-Cu 2 ZnSn characterized in that the elemental composition values (%) of each of sulfur and selenium, (S, Se) 4 thin film is disclosed.
2C is a TEM EDS analytical value that is not calibrated and corresponds to raw data. FIG. 3C is a graph in which FIG. 3 is calibrated. In FIG. 2C, it is meaningful to compare composition ratios according to the depth of the same material, It is difficult to compare the composition values of materials (eg, S and Se) with each other. It is preferable to use the graph of Fig. 3 in order to compare the composition values of different materials (e.g., S and Se) with each other.
As shown in FIG. 3, S / (S + Se) is less than 0.5 over the entire depth range. As shown in FIG. 3, The desired band gap can be obtained.
In another embodiment, a Cu 2 ZnSn (S, Se) 4 thin film for a solar cell is disclosed, wherein the bandgap of the thin film is increasing from the concentration gradient bifurcation point to the surface.
In still other embodiments, the band gap of the thin film is a solar cell-Cu 2 ZnSn (S, Se) 4 thin film, it characterized in that the value of the surface larger 0.08 to 0.12 eV than the lowest point of the interior of the thin-film is disclosed.
Another aspect of the present invention is a method for manufacturing a solar cell comprising the steps of: (A) heat treating a metal alloy thin film composed of a substrate, Mo located on the substrate, and Cu-Zn-Sn alloy located on the Mo, Cu 2 ZnSn (S, Se) 4 thin film.
In one embodiment, the S is supplied by providing H 2 S together with the carrier gas, and the Se is supplied by heating and vaporizing the Se powder to form a Cu 2 ZnSn (S, Se) 4 thin film A method for producing the same is disclosed.
In other embodiments, the (A) step of the solar cell-Cu 2 ZnSn (S, Se) 4 thin film, characterized in that over time, keeping the amount of supply of H 2 S being carried out in the supply amount of Se is reduced atmosphere A manufacturing method is disclosed.
In another embodiment, the step (A) continuously supplies H 2 S together with the carrier gas, stops the heating of the Se powder, and naturally cools to the temperature below the melting point of Se, thereby reducing the amount of Se supplied the method of manufacturing a solar cell-Cu 2 ZnSn (S, Se) 4 thin film, characterized in that is carried out is disclosed.
In the present invention, the natural cooling means that the natural cooling is left without being heated. For example, it can be performed by heating the Se powder to 500 to 600 ° C, holding it for 10 minutes to 1 hour, and then stopping the heating.
In another embodiment, the step (A) is performed in an atmosphere having a partial pressure of S and Se of 0.01 to 0.1 atm in the total pressure (1 atm) of S and Se and the carrier gas. 2 ZnSn (S, Se) 4 thin film is disclosed.
If the upper limit is exceeded, the molybdenum compound is excessively formed on the rear electrode layer, thereby decreasing the conductivity of the rear electrode and increasing the series resistance value. The characteristics of the solar cell can be reduced.
Also, by adjusting the value within the above range, it is possible to control the composition gradient or the degree of inclination according to the depth of sulfur and selenium, and as a result, the gradient or the degree of inclination of the band gap depending on the depth can be controlled. That is, by increasing the pressure value, it is possible to increase the composition gradient or the degree of inclination according to the depth of sulfur and selenium, and to increase the gradient or inclination of the band gap depending on the depth.
In a further embodiment, the (A) step is a method for manufacturing a solar cell 2 ZnSn Cu (S, Se) 4 thin film, it characterized in that the partial pressure ratio of S and Se is 0.2 to 2.0 is disclosed.
If the value is less than the lower limit of the above range, the composition ratio of S and Se in the thin film becomes excessively low, so that the band gap becomes excessively small in the direction of 1.0 eV and the composition gradient does not occur. The composition ratio of S and Se is excessively increased, the band gap may be excessively increased in the direction of 1.5 eV, or a secondary phase may be generated and the problem of increasing the roughness of the thin film may occur.
Another aspect of the present invention relates to a solar cell comprising Cu 2 ZnSn (S, Se) 4 thin film according to various embodiments of the present invention.
Another aspect of the invention (A) the selenium vaporization zone, (B) a metal alloy thin film heating zone, (C-1) H 2 S gas inlet, (C-2) H 2 S for solar cells comprising a gas outlet Cu 2 ZnSn (S, Se) 4 thin film manufacturing apparatus.
H 2 S gas is introduced with the carrier gas through the H 2 S gas inlet and flows into the substrate heating zone together with selenium vapor vaporized in the selenium vaporization zone, and in the metal alloy thin film heating zone, (b- 1) substrate, (b-2) Mo disposed on the substrate, and (b-3) a Cu-Zn-Sn alloy located on the Mo phase.
Hereinafter, the present invention will be described in more detail with reference to Examples and the like, but the scope and content of the present invention can not be construed to be limited or limited by the following Examples. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the present invention as set forth in the following claims. It is natural that it belongs to the claims.
Example
Example 1
Copper-zinc-tin alloy thin films were prepared by electrochemical deposition using potentiostat (model: PARSTAT MC, Princeton Applied Research, USA). The aqueous electrolytes used included copper, zinc, tin cations and additional additives (0.02 M CuSO 4 .5H 2 O, 0.032 M ZnSO 4 .7H 2 O, 0.014 M SnCl 2 , 0.5 M tri-sodium citrate as complexing agent).
Since the conventional three-electrode method is difficult to apply to commercialization, it was deposited using a two-electrode method. Soda lime glass (3 x 4 cm 2 ) deposited with Mo was used as a working electrode, And used as an electrode. Alloy film deposition started with a constant current density of about -1.18 mA / cm 2 for 1,200 seconds. Before deposition, the substrate was cleaned with acetone, ethanol, distilled water, and then dried with nitrogen. The precursor films thus deposited were heat treated in a two-zone cylindrical furnace (FIG. 1), at which time an atmospheric condition of sulfur and selenium was formed and heated to 550 ° C at a rate of 5 ° C per minute and held for 15 minutes. Selenium vapor was formed by evaporating selenium powder at 380 ° C and sulfur vapor H 2 S gas was supplied (200 sccm) in a 1% dilution to Ar gas. While supplying H 2 S, the heating of the selenium powder was stopped and the CZTSSe thin film was formed by natural cooling until the selenium melting point was reached.
At this time, the substrate heating zone may stop heating only the selenium vaporization zone without stopping the heating and naturally cooling, or both the selenium vaporization zone and the substrate heating zone may stop heating and naturally cool. Preferably, both the selenium vaporization zone and the substrate heating zone are more advantageously interrupted and cooled naturally, in that the composition gradient and the bandgap composition gradient can be further increased to further improve the final performance.
The selenium vapor is generated by heating the elemental selenium powder in the selenium vaporization zone and the sulfur vapor is used as the carrier gas by using H 2 S gas mixed with argon, do. For this reason, the sulfur vapor is continuously supplied to the thin film until the heat treatment system is completely cooled, and the selenium vapor is supplied to the thin film until the selenium vaporization zone is cooled below the melting point of selenium.
For reference, selenium is vaporized at the melting point and vaporized together with steam, and the vapor generated in the selenium vaporization zone is transferred to the next zone.
After the formation of the thin film by heat treatment, the second phase of Cu x (S, Se) system was etched for 2 minutes in KCN solution. Then, a 60 nm CdS buffer layer was formed using a chemical wet process to form a pn junction. An i-ZnO / AZO layer (60 nm / 550 nm, RF sputtering), a Ni / Al upper electrode (50 nm / ) Was deposited to fabricate a solar cell. The antireflection film was not used and the area of each cell was about 0.4 cm 2 .
Test Example 1
The crystallographic properties of the prepared CZTSSe thin films were determined by X-ray diffraction spectroscopy (XRD model: D8 advanced, Bruker, Cu-Kα source λ = 1.54060 Å, 40 kV, 30 mA, θ-2θ mode). (EDS: model: PV9761, EDAX) equipped with a transmission electron microscope (TEM: Tecnai F20 G2, FEI, 200 kV) and a limited field electron diffraction pattern and EDS line scanning Respectively. The photocurrent density-voltage characteristics were measured using a solar cell measurement system (Keithley model 2400, solar simulator = model; YSS-50A, Yamashita Denso equipped with a 1000 W Xenon lamp and AM 1.5 filter). The light amount was adjusted to 1 SUN light amount by using the Si photodiode. The external quantum efficiency of the photovoltaic cell was measured using a photovoltaic current conversion efficiency measurement system (Model G1218A, PV Measurements). Capacitance-voltage measurement and admittance spectroscopy were performed using an impedance analyzer (Model: Agilent 4284, Hewlett- Packard). The temperature of the sample was adjusted using a liquid nitrogen-cooled cryostat (Model: LTS420E-P, LINKAM).
Test result
2 (a) compares X-ray diffraction patterns of CZTSSe (band gap 1.13 eV) and CZTSe (band gap 1.02 eV), which is an enlarged view around the diffraction peak of the 112 plane. In both samples, except for Mo and MoSe 2 , no other secondary phases were identified. The figure shows that the diffraction peak of CZTSSe is shifted to an elevation angle, which is replaced with a sulfur atom (covalent radius of 0.102 nm) of smaller selenium atom (covalent radius of 0.116 nm) and a unit cell of CZTSSe ) Is reduced in size. In the diffraction pattern, the sulfur content calculation using the lever rule was 23%, which was very similar to the 24% shown by energy dispersive X-ray spectroscopy (EDS).
FIG. 2 (b) is a cross-sectional clear-sky image using a transmission electron microscope (TEM), and the illustration is a selected area electron diffraction of the corresponding part. Transmission electron microscopy image shows the lamination structure of CZTSSe thin film solar cell, micron - sized crystal grains are distributed in the thin film of 2.5 μm thickness, and cavity is observed on the Mo electrode side. These cavities are found in several reported CZTSSe layers. It was confirmed that the limited field electron diffraction pattern was a single crystal of Kesterites through the clear one, which confirmed that it agrees well with the result of the X-ray diffraction analysis.
FIG. 2 (c) shows the vertical composition distribution of CZTSSe by EDS line scanning. As a result, it can be seen that the remaining elements except sulfur and selenium are relatively uniformly distributed in the CZTSSe thin film. In case of sulfur, And the content of selenium was decreased within the same range.
FIG. 3 shows the sulfur atom composition ratio and the corresponding band gap energy of the CZTSSe thin film according to the vertical direction. It should be noted that the corrected TEM EDS data were corrected through the SEM EDS results. The envelope calculation shows that the surface bandgap is about 0.1 eV larger than the lowest bandgap inside the CZTSSe thin film.
For reference, Cd is the CdS layer immediately above the CZTSSe layer, and it can be seen that the region is about 500 nm deep from the surface.
Thus, the compositional change near the surface appears to have been caused by a post-heat treatment process. During the heat treatment process, selenium vapor is supplied through heating of selenium powder and sulfur vapor is supplied through H 2 S gas diluted in Ar gas. In the case of Se vapor after the heat treatment process, the selenium at a relatively high melting point (about 220 ° C) is cut off relatively quickly due to the temperature drop. In the case of sulfur vapor, however, due to the continuous flow of H 2 S, . For this reason, it is easy for sulfur atoms to substitute for selenium atoms during cooling. The composition gradient of the sulfur / selenium atoms along the vertical direction creates a bandgap gradient in the CZTSSe film, which appears to affect the photoelectric properties of this film.
4 (a) compares light and dark current-voltage curvature of CZTSSe with CZTSe, and black line means CZTSSe gray line means CZTSe. Detailed solar cell parameters and electrical characteristics are summarized in Table 1. In the case of CZTSSe, which showed the highest efficiency, the short circuit current ( J sc ) was 33.7 mA / cm 2 , the open circuit voltage ( V oc ) was 0.48 V and the fill factor (FF) was 0.61 at 9.9 eV. A 24% improvement in efficiency was observed due to the addition of S atoms when compared to a CZTSe thin film solar cell with a bandgap of 1.02 eV, with an increase in open-circuit voltage of 23%, an increase in filling rate of 7%, and a shorting current reduction of 5%.
The factors affecting the short-circuit current were examined through the external quantum efficiency (EQE) curve (Fig. 4 (b)). It was confirmed that the absorption edge of the external quantum efficiency curve was shifted to the shorter wavelength due to the increase of the bandgap due to the addition of the sulfur atom. In the calculation of the band gap using the external quantum efficiency curve, the band gap showed 1.13 eV, which is similar to the 1.12 eV shown in the X-ray diffraction peak analysis and EDS analysis. Although the absorption spectrum is smaller than that of CZTSe, the short-circuit current shows a small decrease (33.4 mA / cm 2 -> 31.6 mA / cm 2 ). This is thought to be due to an increase in the light response at the longer wavelength side. The reason why the light response near the long wavelength is increased seems to be that the probability of collecting the minority carriers generated near the back electrode is increased due to the decrease in the thickness of the thin film. The shortcircuit current can be increased sufficiently by improving the CdS layer and the TCO layer and using the reflection ring film. The increased open-circuit voltage seems to have been mainly caused by the increase in band gap because the open-circuit voltage shortage ( V oc deficit = E g / q- V oc ) of CZTSSe is 0.65 V which is similar to 0.63 V of CZTSe Because. The increase in bandgap due to the addition of sulfur atoms may have resulted in a decrease in the reverse saturation current ( J 0 ) and shunt conductance, which leads to an improvement in the diode ideality factor and filling factor .
(%)
(V)
(eV)
(eV)
(mA
/ cm 2 )
(Ωcm 2 )
(mA
/ cm 2 )
FIG. 5 shows the effect of temperature on the open-circuit voltage of a CZTSSe thin-film solar cell, which gives information on the dark current and the electron-recombination method. The temperature dependence of the open-circuit voltage is expressed by the following relationship.
[Equation 1]
In this case, E A , A , k , T , J 00 , and J L represent the activation energy, the ideal diode factor, the absolute temperature, the reverse saturation current density factor, and the photocurrent density of the main recombination mechanism, respectively. If the open-circuit voltage exhibits a linear dependence on temperature, it can be said that A , J 00 , J L do not depend on the temperature. Therefore, the activation energies EA / q are calculated by using data extrapolation in the Voc-T plot and V oc Value, and it has an activation energy of about 0.99 eV. This is the largest value of CZTSSe with similar band gaps reported previously. The difference between the relatively small activation energy and the band gap energy (0.14 eV) suggests that the interface recombination between the buffer layer and the photoabsorption layer may be reduced. This is a good explanation for the effect of increasing the content of sulfur atoms on the aforementioned surface. Figure 3b shows the admittance spectral characteristics of CZTSSe thin film solar cell. Due to the relaxation behavior of the capacitance with respect to the measurement frequency, the characteristic frequency ( ω 0 ) is as shown in Figure 3b. d C ( ? ) / d ln ? the maximum value of ω plot. The characteristic frequency is determined by the following equations: the attempt-to-escape frequency (ν 0 ), the emission factor ( ξ 0 ), the defective energy ( E d : the energy distance difference between the valence band and the defect level), the Boltzmann constant ( k ) T ).
&Quot; (2) "
The Ed value is determined by the slope of ln (ω 0 / T 2 ) vs. 1 / Tplot as shown in Figure 3b and is confirmed to be 105 mV. It can be seen that this is somewhat similar to the activation energy difference (140 mV) of the previously measured band gap and main recombination mechanism.
As shown above, CZTSSe thin film solar cell through electrochemical deposition and post heat treatment process showed high efficiency of 9.9%. Band gap adjustment and bandgap inclination are important factors. When compared with pure CZTSe with a bandgap of 1.02 eV, CZTSSe thin film solar cell with a band gap of 1.13 eV has a bandgap increase, a small reverse saturation current and an increased shunt resistance The open-circuit voltage was greatly increased. On the other hand, the decrease in the light absorption spectrum due to the increase in the band gap has resulted in a relatively small decrease in the open current due to the improvement in the optical response near the band edge, which is presumably related to the band gap slope. In addition, this CZTSSe thin film solar cell exhibited a relatively high primary recombination mechanism activation energy, which appears to be due to an increase in the content of sulfur atoms near the surface.
Example 2
In the production of CZTSSe thin film using the heat treatment system shown in FIG. 1, the internal partial pressure of sulfur or selenium is closely related to the final CZTSSe thin film solar cell. When the internal partial pressure is insufficient, the anion sulfur or selenium (MoSe x or MoS x or MoSe x S y ) is excessively formed on the rear electrode layer and the conductivity of the back electrode is excessively high, It is confirmed that the series resistance of the solar cell can be increased and the solar cell characteristics can be further reduced.
In addition, the thin film produced in the region where the internal partial pressure is too high is difficult to have a flat surface due to excessive growth of particles, and when the surface is not flat, the overall efficiency of the solar cell is deteriorated due to the possibility of recombination due to the increase of the interface. It was confirmed that maintaining proper internal partial pressure is very important because it is imported.
Example 3
Sulfur and selenium ratio and bandgap of the CZTSSe thin film were determined by the ratio of sulfur and selenium in the atmosphere in the heat treated tube. It was confirmed that not only this ratio but also the total pressure inside the heat treatment tube had an effect of CZTSSe. The system according to one embodiment of the present invention produces selenium vapor through particle vaporization, whereas sulfur provides through an H 2 S gas supply. At this time, when the exhaust pressure of the heat treatment tube is increased to increase the internal total pressure (for example, 1.2 atm), the selenium supply stops more rapidly than when the internal total pressure of 1 atm is formed in a general heat treatment, The slope of the slope of the photovoltaic device can be rapidly increased to form a graded thin film whose surface sulfur ratio is increased compared with the inside. This can reduce the surface recombination and selectively increase the bandgap to improve the rectifying characteristic of the solar cell device As a result, it was confirmed that solar cell characteristics can be improved.
Claims (14)
(S s - S v ) is a positive number, (Se s - Se v ) is a negative number,
S s and S v are the compositional values (atomic%) of sulfur at the surface and composition gradient point, respectively,
The Se Se v s and the solar cell 2 ZnSn Cu (S, Se), characterized in that the composition value (atomic%) of Se in the respective surface of the fork 4 and the composition gradient film.
Wherein S and Se are elemental compositional values (atomic%) of sulfur and selenium, respectively, for Cu 2 ZnSn (S, Se) 4 thin film for solar cells.
Wherein S and Se are elemental compositional values (atomic%) of sulfur and selenium, respectively, for Cu 2 ZnSn (S, Se) 4 thin film for solar cells.
Wherein S and Se are elemental compositional values (atomic%) of sulfur and selenium, respectively, for Cu 2 ZnSn (S, Se) 4 thin film for solar cells.
In the Cu 2 ZnSn (S, Se) 4 thin film, (S s - S v ) is a positive number, (Se s - Se v )
S s and S v are the compositional values (atomic%) of sulfur at the surface and composition gradient point, respectively,
The Se Se s and v are each surface and the solar cell manufacturing method of Cu 2 ZnSn (S, Se) 4 thin film, characterized in that the composition value (atomic%) of selenium in the composition gradient of the fork.
The method for manufacturing a solar cell is Se Cu 2 ZnSn (S, Se) 4 thin film, characterized in that supplied by vaporization by heating the Se powder.
H 2 S gas is introduced into the metal alloy thin film heating zone together with the vaporized selenium vapor in the selenium vaporization zone through the H 2 S gas inlet,
(B-1) substrate, (b-2) Mo disposed on the substrate, and (b-3) a Cu-Zn-Sn alloy disposed on the Mo phase in the metal alloy thin film heating zone,
In the Cu 2 ZnSn (S, Se) 4 thin film, (S s - S v ) is a positive number, (Se s - Se v )
S s and S v are the compositional values (atomic%) of sulfur at the surface and composition gradient point, respectively,
The Se Se s and v is the solar cell 2 ZnSn Cu (S, Se), it characterized in that the composition value (atomic%) of Se in the respective surface and the composition gradient produced the fork 4 of the thin film device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020150020601A KR101733438B1 (en) | 2015-02-11 | 2015-02-11 | Compositionally graded CZTSSe thin film and its preparation method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020150020601A KR101733438B1 (en) | 2015-02-11 | 2015-02-11 | Compositionally graded CZTSSe thin film and its preparation method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| KR20160098695A KR20160098695A (en) | 2016-08-19 |
| KR101733438B1 true KR101733438B1 (en) | 2017-05-11 |
Family
ID=56874787
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| KR1020150020601A KR101733438B1 (en) | 2015-02-11 | 2015-02-11 | Compositionally graded CZTSSe thin film and its preparation method |
Country Status (1)
| Country | Link |
|---|---|
| KR (1) | KR101733438B1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR102370315B1 (en) | 2020-10-28 | 2022-03-04 | 재단법인대구경북과학기술원 | Method for manufacturing light absorption layer of solar cell |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108155256B (en) * | 2016-12-02 | 2020-03-10 | 北京有色金属研究总院 | Copper-zinc-tin-sulfur thin-film solar cell with absorption layer having element gradient and preparation method thereof |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2014513413A (en) | 2011-03-10 | 2014-05-29 | サン−ゴバン グラス フランス | Method for producing ternary compound semiconductor CZTSSe and thin film solar cell |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101339874B1 (en) | 2012-06-20 | 2013-12-10 | 한국에너지기술연구원 | Manufacturing method of double grading czts thin film, manufacturing method of double grading czts solar cell and czts solar cell |
-
2015
- 2015-02-11 KR KR1020150020601A patent/KR101733438B1/en active IP Right Grant
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2014513413A (en) | 2011-03-10 | 2014-05-29 | サン−ゴバン グラス フランス | Method for producing ternary compound semiconductor CZTSSe and thin film solar cell |
Non-Patent Citations (2)
| Title |
|---|
| 논문 1 |
| 논문 2 |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR102370315B1 (en) | 2020-10-28 | 2022-03-04 | 재단법인대구경북과학기술원 | Method for manufacturing light absorption layer of solar cell |
Also Published As
| Publication number | Publication date |
|---|---|
| KR20160098695A (en) | 2016-08-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Son et al. | Effect of solid-H 2 S gas reactions on CZTSSe thin film growth and photovoltaic properties of a 12.62% efficiency device | |
| Zhuk et al. | Critical review on sputter-deposited Cu2ZnSnS4 (CZTS) based thin film photovoltaic technology focusing on device architecture and absorber quality on the solar cells performance | |
| Fernandes et al. | Cu2ZnSnS4 solar cells prepared with sulphurized dc-sputtered stacked metallic precursors | |
| Romeo et al. | Low substrate temperature CdTe solar cells: A review | |
| Mkawi et al. | Substrate temperature effect during the deposition of (Cu/Sn/Cu/Zn) stacked precursor CZTS thin film deposited by electron-beam evaporation | |
| Feng et al. | A low-temperature formation path toward highly efficient Se-free Cu 2 ZnSnS 4 solar cells fabricated through sputtering and sulfurization | |
| KR101628312B1 (en) | PREPARATION METHOD OF CZTSSe-BASED THIN FILM SOLAR CELL AND CZTSSe-BASED THIN FILM SOLAR CELL PREPARED BY THE METHOD | |
| KR101747395B1 (en) | Molybdenum substrates for cigs photovoltaic devices | |
| Lin et al. | Crystallographic orientation control and defect passivation for high-efficient antimony selenide thin-film solar cells | |
| Seo et al. | Compositional and Interfacial Modification of Cu2ZnSn (S, Se) 4 Thin‐Film Solar Cells Prepared by Electrochemical Deposition | |
| Mkawi et al. | Influence of substrate temperature on the properties of electrodeposited kesterite Cu 2 ZnSnS 4 (CZTS) thin films for photovoltaic applications | |
| Wei et al. | Effects of selenium atmosphere on grain growth for CZTSe absorbers fabricated by selenization of as-sputtered precursors | |
| Soni et al. | Sputtering as a viable route for In2S3 buffer layer deposition in high efficiency Cu (In, Ga) Se2 solar cells | |
| Ren et al. | CZTSSe solar cell with an efficiency of 10.19% based on absorbers with homogeneous composition and structure using a novel two-step annealing process | |
| Dale et al. | Characterization of CuInSe2 material and devices: comparison of thermal and electrochemically prepared absorber layers | |
| Zhao et al. | Fabrication and characterization of Cu2ZnSnS4 thin films by sputtering a single target at different temperature | |
| Wu et al. | The effect of Rb doping on CZTSSe solar cells | |
| KR101733438B1 (en) | Compositionally graded CZTSSe thin film and its preparation method | |
| Khan et al. | Highly efficient Cu2ZnSn (S, Se) 4 bifacial solar cell via a composition gradient strategy through the molecular ink | |
| Yu et al. | The role of tuning Se/(S+ Se) ratio in the improvement of Cu2MnSn (S, Se) 4 thin films properties and photovoltaic device performance | |
| JP6316877B2 (en) | Method for forming ACIGS thin film at low temperature and method for manufacturing solar cell using the same | |
| Jeong et al. | Influence of precursor uniformity on the performance of Cu2ZnSnSxSe4− x thin film solar cells prepared by the sputtering method | |
| Mao et al. | Eliminating cracking morphology of solution-processed CZTSSe absorbers by Sn-rich composition engineering | |
| Tao et al. | Efficiency enhancement of CZTSe solar cells based on in situ K-doped precursor | |
| Wang et al. | Using soda-lime glass transition temperature to enhance the efficiency of Cu2ZnSn (S, Se) 4 solar cell |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A201 | Request for examination | ||
| E902 | Notification of reason for refusal | ||
| E902 | Notification of reason for refusal | ||
| E902 | Notification of reason for refusal | ||
| E701 | Decision to grant or registration of patent right |