DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Status of claims
The amendment to claims filed on 7/24/2026 is acknowledged. Claims 1 and 9 are amended. Currently, claims 1, 6-10 are pending in the application with claims 9-10 being withdrawn from consideration.
Previous 112 rejection is withdrawn in view of the above amendment.
Previous prior art rejection is withdrawn in view of the above amendment.
Claims 1 and 6-8 are rejected on a new ground of rejection. See the rejection below.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claim(s) 1, and 6-7 are rejected under 35 U.S.C. 103 as being unpatentable over Bush (US Patent 10,644,179) in view of Kim (US 2011/0195196), McManus et al. (“Highly Soluble Ligand Stabilized Tin Oxide Nanocrystals: Gel Formation and Thin Film Production”) and Lin et al. (“ZnO-Modified Anode for High Performance SnO2-Based Planar Perovskite Solar Cells”), and further in view of Fujimura (US 2017/0018372).
Regarding claim 1, Bush discloses a perovskite solar cell comprising a laminate in which a hole transport layer (see HTL 330, fig. 4A), a perovskite light absorption layer (see absorber 320, fig. 4A; col. 7, lines 58-59), an electron transporting layer (ETL-1 310, fig. 4A), and a source electrode (electrode 250) are sequentially stacked; wherein a conductive barrier layer (ETL-2 or conformal transport layer 240) is formed between the source electrode (250) and the electron transporting layer (ETL-1 310); wherein the electron transport layer (ETL-1 310) is in direct contact with the conductive barrier (ETL-2 240); and wherein the conductive barrier layer (240) is a transparent thin film deposited with ITO (indium tin oxide), AZO (aluminum doped zinc oxide) and IZO (see col. 7 lines 4-34).
Bush teaches the conductive barrier layer (ETL-2 or conformal transport layer 240) having a thickness of less than 150nm (see col. 7, lines 14-15; col. 14, lines 36-46; claim 6). Bush does not explicitly teach the conductive barrier layer (ETL-2) having an average thickness of 60 to 100nm and a sheet resistance of 30.0 to 70W/sq.
Kim discloses an IZO layer having a thickness of 100nm being treated to have a sheet resistance of 30-43W/sq (see [0040] and fig. 5). 100nm is in the claimed range of 60 to 100nm, and 30-43 W/sq is right within the claimed range of 30.0 to 70 W/sq.
It would have been obvious to one of ordinary skill in the art at the time of invention to have used the IZO layer having a thickness of 100nm and sheet resistance of 30-43W/sq as taught by Kim as the conductive barrier (ETL-2) of Bush; because Bush explicitly teaches using IZO with a thickness of less than 150nm, and Kim teaches such transparent conductive oxide film has improved conductivity, roughness and enhanced light transmittivity (see [0004] of Kim).
Bush teaches using tin oxide (or SnO2) for the electron transporting layer (310, see col. 8, lines 19-36). Bush does not explicitly teach the electron transporting layer composed of SnO2 (or tin oxide) nanoparticles having an average diameter of 3 to 5 nm and having surface modified with a compound represented by the claimed formula 1 such that the electron transporting layer exhibits a light transmittance of 90.9 to 95% within a wavelength range of 500 to 550nm.
McManus et al. teaches surface modified tin oxide particles with acetic acid and trifluoroacetic acid is highly soluble stabilized tin oxide, soluble in common organic solvent and may be stored indefinitely in the solid state with no loss of solubility and using surface modified tin oxide would permit the preparation of high quality thin films with simple solution processing techniques (see abstract, fig. 6, page 4825), wherein the particles having an average particle diameter of 3nm (see table 1) or 4nm (see page 4825, left column). Acetic acid is a compound of formula 1 with R1 to R5 being a hydrogen and n being 0. Trifluoroacetic acid is a compound of formula 1 with R1 to R5 being a halogen atom, or fluoride (F) and n being 0. 3nm and 4nm are right within the claimed range of 3-5nm.
It would have been obvious to one skilled in the art before the effective filing date of the claimed invention to modify the solar cell of modified Bush by utilizing the surface modified SnO2 particles taught by McManus et al. to form the SnO2 electron transport layer; because McManus et al. teaches using surface modified SnO2 nanoparticles would permit the preparation of high quality films with simple solution processing techniques. In such modification, the electron transport layer formed by the surface modified SnO2 nanoparticles – or the same material as claimed – of modified Bush will display the same characteristic/property of having “a light transmittance of 90.9 to 95% for a wavelength of 500 to 550nm” as claimed. See MPEP 2112.
Bush shows both the conductive barrier layer (240) and the electron transporting layer (310) are electron transporting layer (or ETL 2 and ETL 1 respectively, see fig. 4A), and teaches the thickness of one of the electron transport layers (or the conductive barrier/or conformal transport layer/or ETL2 240) to be 10nm to 40nm and sufficiently thin to transport charge through its thickness, and not be laterally conductive (see col. 7, lines 15-16; col. 9, lines 26-27; col. 12, lines 5-6; col. 14, lines 36-46). Bush does not explicitly teach the electron transporting layer (ETL-1 310) having a thickness of 1nm to 40nm.
Lin et al. teaches adjusting the thickness of the SnO2 electron transporting layer to pursue an optimal cell performance, wherein the optimized SnO2 thickness is found to be 25nm, or 20nm with the conductive barrier (or additional layer of ZnO) between the electrode (ITO) and the electron transporting layer composed of SnO2 (see fig. 1, and “Results and Discussion”). It is noted that 20 nm or 25nm are right within the claimed range of 1nm to 40nm.
It would have been obvious to one skilled in the art before the effective filing date of the claimed invention to modify the solar cell of Bush by forming an electron transporting layer being composed of SnO2 and having a thickness 20nm or 25nm as taught by Lin et al.; because Lin et al. teaches such thicknesses of the SnO2 would provide optimal performance of the solar cell, and Bush explicitly suggests teaches the thickness of a charge transporting layer in the range of 10nm to 40nm to sufficiently transport charge through its thickness, and not be laterally conductive.
Bush shows the electron transport layer (ETL-1 320) is flat (see fig. 4A), and the conductive barrier layer (240) is a conformal transport layer (see cols. 6-8). McManus et al. shows the tin oxide formed by surface modified SnO2 nanoparticles are substantially smooth (see fig. 6, especially fig. 6f) and a dip coated glass gives very low surface roughness values of between 5 and 7Å (see fig. 6b, and the third paragraph of the left column of page 4825). Modified Bush does not explicitly disclose the surface of the electron transporting layer has a root-mean-square (RMS) roughness of 17.5 to 24.0nm or less, nor do they teach a surface of the conductive barrier layer has an RMS roughness of 30nm or less.
Fujimura et al. teaches an electron transport layer is desirably flat to have an arithmetic means roughness Ra of less than 50nm to have a small thickness with reduced resistance, thereby increasing the conversion efficiency of the solar cell (see [0044]).
Therefore, it would have been obvious to one skilled in the art before the effective filing date of the claimed invention to have formed the electron transporting layers of modified Bush, or the conductive barrier layer (ETL-2 240) and the electron transporting layer (ETL-1 310), to have an arithmetic means – or root-mean-square – roughness Ra of less than 50nm as taught by Fujimura et al.; because McManus et al. teaches the electron transport layer (e.g. ETL-1 310) formed by surface modified SnO2 nanoparticles would provide a low surface roughness values and Bush teaches the conductive barrier layer (or ETL-2 240) is a conformal transport layer (or a transport layer following the same shape, e.g. roughness, as the electron transporting layer ETL-1 310), and Fujimura et al. teaches a flat electron transport layer having an arithmetic means roughness Ra of less than 50nm is desirable to reduce thickness and resistance of the electron transport layer and thereby increasing the conversion efficiency of the solar cell. In addition, it would have been obvious to one of ordinary skill in the art at the time of invention to have selected the overlapping portion of 17.5 to 24.0nm or less in the range of less than 50nm taught by Fujimura et al.; because selection of overlapping portion of ranges has been held to be a prima facie case of obviousness. In re Malagari, 182 USPQ 549. It is noted that 17.5 to 24.0nm or less is right within the claimed range of 30nm or less.
Regarding claim 6, modified Bush discloses a perovskite solar cell as in claim 1 above, wherein Bush discloses the perovskite solar cell is an inverted-structure perovskite solar cell (fig. 4A), a tandem-type perovskite solar cell or a tandem-type silicon/perovskite heterojunction solar cell (4B).
Regarding claim 7, modified Bush discloses a perovskite solar cell as in claim 6 above, wherein Bush discloses the perovskite solar cell is an inverted-structure perovskite solar cell, and comprises a structure in which a drain electrode (210, fig. 4A), the hole transport layer (HTL 330), the perovskite light absorption layer (320), the electron transporting layer (ETL -1 310), the conductive barrier layer (ETL-2 240), and the source electrode (250) are sequentially stacked (see fig. 4A).
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over modified Bush (US Patent 10,644,179) as applied to claim 1 above, and further in view of Bush, Kevin A. et al. (“23.6%-Efficient Monolithic Perovskite/silicon Tandem Solar Cells with Improved Stability”).
Regarding claim 8, modified Bush discloses a perovskite solar cell as in claim 6 above, wherein Bush discloses the perovskite solar cell is a tandem-type cell including perovskite material in one or both of the subcells (see col. 11, lines 2-16), wherein the tandem cell comprises a drain electrode (210, fig. 4B), bottom subcell (330/320/310, fig. 4B), a recombination layer (340, fig. 4B), a hole transport layer (370, fig. 4B), a perovskite light absorption layer (360, fig. 4B), an electron transporting layer (ETL-1 350, fig. 4B), a conductive barrier layer (ETL-2 240), and a source electrode (250) are sequentially stacked (see fig. 4B).
Bush shows the tandem cell including perovskite material in both of the subcells in fig. 4B.
Modified Bush, or more specifically Bush does not explicitly show the tandem cell including perovskite material in one of the subcell such that the bottom subcell is a silicon solar cell.
Bush, Kevin A. et al. shows a tandem solar cells including a top perovskite subcell and a bottom subcell is a silicon solar cell (a-Si:H (n+)/a-Si:H(i)/c-Si(n)/a-Si:H(i)/a-Si:H(p+) to improve the efficiency of the solar cell by increasing the absorption spectrum, e.g. combination absorption spectrum of perovskite and silicon (see figs. 2(a) and 2(f)-(g)).
It would have been obvious to one skilled in the art before the effective filing date of the claimed invention to modify the solar cell of modified Bush by using silicon solar cell for the bottom subcell as taught by Bush, Kevin A. et al.; because Bush explicitly teaches a tandem cell including perovskite in one of the subcell and Bush, Kevin A. et al. teaches a tandem cell including a perovskite in one of the subcell, or the top subcell, and silicon for the bottom subcell to increase efficiency by combining absorption spectrum of silicon and perovskite.
Response to Arguments
Applicant’s arguments with respect to claim(s) 1 and 6-8 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Applicant argues none of the cited references teach the or suggests SnO2 nanoparticles having an average particle diameter of 3 to 5nm as claimed; because according to Applicant even if McManus reports grain size of the tin oxide material, the reference contains no clear disclosure of the average particle diameter of its surface-modified particles and nowhere discloses or suggests an average particle diameter of 3 to 5nm. The examiner replies that crystallites having a single measured size 3nm shown in table 1 of McManus correspond to the claimed nanoparticles having an average diameter. McManus also explicitly describes “[t]he average crystallite diameters of all materials, as calculated by the Scherrer equation, are of the order of 2 to 4nm. Transmission electron microscopy images (Figure 1b, c) show crystalline domains of 3-5nm with some amount of bridging between particles” the in right column of page 4820. As such, the crystallite size shown in table 1, as a matter of fact, is an average diameter, because McManus explicitly describes so.
Applicant argues none of the previously cited references teach the claimed thickness and sheet resistance of the conductive barrier. However, Applicant’s arguments are moot in view of the new ground of rejection.
Applicant points to table 3 to show unexpected results of the claimed barrier layer thickness and sheet resistance. However, table 3 shows the examples 2 and 3 with barrier layer thickness and sheet resistance within the claimed ranges have inferior performances than the examples 4, 5 and comparative example 4 with barrier layer thickness and sheet resistance outside the claimed range. Inferior performances are not unexpected results. See MPEP 716.02.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to THANH-TRUC TRINH whose telephone number is (571)272-6594. The examiner can normally be reached 9:00am - 6:00pm.
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THANH-TRUC TRINH
Primary Examiner
Art Unit 1726
/THANH TRUC TRINH/Primary Examiner, Art Unit 1726
