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
Claims 1-2, and 5-9 as amended in applicant’s response dated 22 April 2026 are presently under consideration. Claims 3-4 are cancelled by applicant’s amendments.
Applicant’s amendments to the claims have overcome the indefiniteness rejections of record, which are thus withdrawn.
Upon further search and consideration of applicant’s newly amended claims, a new grounds of rejection over the prior art of record is presented below.
Applicant’s arguments and remarks where applicable are addressed below.
Response to Arguments
Applicant's arguments filed 22 April 2026 have been fully considered but they are not persuasive.
Applicant argues on page 7 of the response dated 22 April 2026 that “the instant claims are directed to an electron carrier for an electron transport layer of a perovskite solar cell that can be formed without high-temperature processes that would otherwise degrade a perovskite active layer”, however applicant’s argument is not found persuasive as it is not commensurate with the scope of the claims.
In response to applicant's argument that the references fail to show certain features of the invention, it is noted that the features upon which applicant relies (i.e., “an inverted perovskite solar cell” or “a perovskite solar cell that can be formed without high-temperature processes that would otherwise degrade a perovskite active layer”) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993).
Applicant’s further arguments on pages 7-8 of the response dated 22 April 2026 that “As Valadez-Villalobos discloses perovskite solar cells that are manufactured in a completely different order from the instant claims, it is applicant’s position that there is absolutely no need to include distinct process steps to prevent degradation of the perovskite active layer. Thus, one of ordinary skill in the art would not be motivated to modify Valadez- Villalobos to include a step where surface modification of metal oxide nanoparticles is performed, as the effectiveness of the modification proposed by the Examiner would not be apparent in a process of manufacturing perovskite solar cells having a conventional structure, as clearly disclosed in Valadez-Villalobos“ are likewise not found persuasive as they are also not commensurate in scope with the limitations of the claims. The claims do not recite a method of forming a perovskite solar cell with an inverted structure but for example at claim 1 are more broadly directed to “an electron carrier”.
Applicant further argues on page 8 of the response dated 22 April 2026 that Valadez-Villalobos discloses a different structure from the electron transport layer according to the instant claims. Applicant’s arguments have been fully considered but are not found persuasive as they are not commensurate in scope with the limitations of the claims. As previously recited, claim 1 is directed more broadly to “an electron carrier” not specifically to the electron layer of a perovskite solar cell itself and does not further limit the structure to distinguish over a two layer structure of a metal oxide nanoparticle layer formed first and having a B4PI layer deposited thereon as in Valadez-Villalobos of TiO2 nanoparticles coated with tetrabutylphosphonium iodide (B4PI) for interface modification (surface modified) and functions as the ETL in a perovskite cell (Fig. 1).
Applicant’s further arguments to this point depend from the arguments rebutted above and are thus considered moot.
Applicant’s further arguments to Leung are moot in view of the new grounds of rejection set forth above.
To the extent that the arguments to Leung are applicable to the prior art of Burschka et al (US 2016/0086739), they are found unpersuasive as one of ordinary skill in the art would understand, a TiO2 mesoporous scaffolding layer in a perovskite solar cell also functions as an electron transport layer and thus applicant’s arguments that a TiO2 mesoporous scaffolding layer is different from a broadly recited electron transport layer are not found persuasive.
Applicant’s further arguments and remarks are moot in view of the new grounds of rejection set forth above or are moot for depending from the arguments rebutted above.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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.
Claims 1, 5, and 7-9 are rejected under 35 U.S.C. 103 as being unpatentable over Valadez-Villalobos et al (Effect of Tetrabutylphosphonium Iodide as Interfacial Additive between Tio2 and Ch3nh3pbi3 in Mesoscopic Perovskite Solar Cells. Available at SSRN: https://ssrn.com/abstract=4170575 or http://dx.doi.org/10.2139/ssrn.4170575, posted 23 Jul 2022), and further in view of Burschka et al (US 2016/0086739).
Regarding claim 1 Valadez-Villalobos discloses an electron carrier for an electron transport layer of a perovskite solar cell, comprising metal oxide nanoparticles that are surface-modified with a phosphonium salt represented by Chemical Formula 1 below:
PNG
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102
140
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Greyscale
wherein in Chemical Formula 1, each of R1 to R4 is independently a C1 to C10 straight- chain alkyl group, a C3 to C10 branched alkyl group, a phenyl group or a benzyl group, and X is a halogen atom or -OH (See Abstract and sections “2.3 Fabrication of films and devices”, 2.4 Interfacial modification with B4PI see: TiO2 mesoporous film which is formed of TiO2 nanoparticles is coated with tetrabutylphosphonium iodide (B4PI) for interface modification (surface modified) and functions as the ETL in a perovskite cell (Fig. 1) where B4PI is a phosphonium salt represented by Chemical Formula 1 where R1 to R4 is C4 alkyl group and X is I).
It’s not clear Valadez-Villalobos explicitly discloses wherein the electron carrier comprises 85.0 to 95.0 wt% of the metal oxide nanoparticles and the remaining amount of a surface modification component based on the total weight of the electron carrier.
However, Valadez-Villalobos teaches the device stability and photoelectric conversion efficiency are variables that can be modified by varying the amount of a surface modification component (B4PI) (see Abstract and pages 9-12) and thus also varying the amount of TiO2 based on total weight of the electron carrier.
As such, the weight amounts of the metal oxide nanoparticles and surface modification component in the electron carrier of Valadez-Villalobos would have been considered result effective variables. The court has held that absent criticality or unexpected results, it would be obvious for a person having ordinary skill in the art to optimize the weight amounts of the metal oxide nanoparticles and surface modification component in the electron carrier of Valadez-Villalobos to achieve the desired optimized device stability and photoelectric conversion efficiency. Differences in said result effective variable will not support the patentability of subject matter encompassed by the prior art. "Where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." See In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). See also MPEP § 2144.05.
Valadez-Villalobos does not explicitly disclose wherein the metal oxide nanoparticles have a particle size of 2 nm to 20 nm.
However, Burschka discloses mesoporous metal oxide (TiO2) electron transport layers for perovskite solar cells having metal oxide nanoparticles with a particle size in the range of 2 to 300 nm, preferably 3 to 200 nm, even more preferably 4 to 150 nm, still more preferably 5 to 100 nm, and most preferably 5 to 40 nm (para [0064]).
Burschka and Valadez-Villalobos are combinable as they are both concerned with perovskite solar cells.
It would have been obvious to one having ordinary skill in the art at the time of the invention to modify the electron carrier of Valadez-Villalobos in view of Burschka such that the metal oxide nanoparticles of Valadez-Villalobos have a particle size of preferably 5 to 40 nm as in Burschka (para [0064], [0071]) as such a modification would have amounted to the selection of a known mesoporous titanium oxide nanoparticle size for its intended use in an electron transport layer of a perovskite solar cell to accomplish an entirely expected result of providing electron transport and serving as a scaffold for the perovskite material. Furthermore, the recited nanoparticle size range of 5 nm to 40 nm substantially overlaps applicant’s claimed range. It is well settled that where the prior art describes the components of a claimed compound or compositions in concentrations within or overlapping the claimed concentrations a prima facie case of obviousness is established. See In re Harris, 409 F.3d 1339, 1343, 74 USPQ2d 1951, 1953 (Fed. Cir 2005); In re Peterson, 315 F.3d 1325, 1329, 65 USPQ 2d 1379, 1382 (Fed. Cir. 1997); In re Woodruff, 919 F.2d 1575, 1578 16 USPQ2d 1934, 1936-37 (CCPA 1990); In re Malagari, 499 F.2d 1297, 1303, 182 USPQ 549, 553 (CCPA 1974).
Regarding claim 5 modified Valadez-Villalobos discloses a coating agent for an electron transport layer of a perovskite solar cell, comprising an organic solvent and the electron carrier according to claim 1 (See sections “2.3 Fabrication of films and devices”, 2.4 Interfacial modification with B4PI see: TiO2 mesoporous film which is formed of TiO2 nanoparticles is coated with tetrabutylphosphonium iodide (B4PI) in isopropanol, where the deposited isopropanol with B4PI on TiO2 prior to drying meets the limitations of the claimed coating agent as claimed) wherein the organic solvent has a dielectric constant of 20 or less (isopropanol).
Regarding claim 7 modified Valadez-Villalobos discloses the coating agent of claim 5, wherein the organic solvent comprises at least one selected from isopropyl alcohol, butyl alcohol, 2,2,2-trifluoroethanol, chlorobenzene and chloroform See sections “2.3 Fabrication of films and devices”, 2.4 Interfacial modification with B4PI see: isopropanol).
Regarding claim 8 modified Valadez-Villalobos discloses an electron transport layer of a perovskite solar cell, comprising a coating layer formed by the coating agent of claim 5 (See Abstract and sections “2.3 Fabrication of films and devices”, 2.4 Interfacial modification with B4PI see: TiO2 mesoporous film which is formed of TiO2 nanoparticles is coated with tetrabutylphosphonium iodide (B4PI) for interface modification (surface modified) and functions as the ETL in a perovskite cell (Fig. 1).
Regarding claim 9 modified Valadez-Villalobos discloses the electron transport layer of claim 8, and regarding the claim 9 recitation “wherein the electron transport layer has a thickness of 10 nm to 200 nm” Burschka discloses mesoporous metal oxide electron transport layers for perovskite solar cells having a thick of 10 nm to 3000 nm, preferably 15 nm to 1500 nm, more preferably 20 nm to 1000 nm, still more preferably 50 to 800 nm and most preferably 100 nm to 500 nm (Burschka, [0022]-[0028]) which entirely or substantially overlaps applicant’s claimed range. It is well settled that where the prior art describes the components of a claimed compound or compositions in concentrations within or overlapping the claimed concentrations a prima facie case of obviousness is established. See In re Harris, 409 F.3d 1339, 1343, 74 USPQ2d 1951, 1953 (Fed. Cir 2005); In re Peterson, 315 F.3d 1325, 1329, 65 USPQ 2d 1379, 1382 (Fed. Cir. 1997); In re Woodruff, 919 F.2d 1575, 1578 16 USPQ2d 1934, 1936-37 (CCPA 1990); In re Malagari, 499 F.2d 1297, 1303, 182 USPQ 549, 553 (CCPA 1974).
Additionally, the claim 9 recitation “wherein when the electron transport layer has a thickness of 10 nm to 15 nm, the electron transport layer has a light transmittance of 88.0% or more for a wavelength of 500 to 550 nm” is directed to an intended use of the claimed device. A recitation directed to the manner in which a claimed apparatus is intended to be used does not distinguish the claimed apparatus from the prior art, if the prior art has the capability to so perform. See MPEP 2111.02, 2112.01 and 2114-2115.
The electron transport layer of Valadez-Villalobos is considered fully capable of having the recited light transmittance of 88.0% or more for a wavelength of 500 to 550 nm at when at a thickness of 10 nm to 15 nm as such a electron transport layer is open to having windows or patterning to provide said light transmittance.
Claim 2 is rejected under 35 U.S.C. 103 as being unpatentable over Valadez-Villalobos et al (Effect of Tetrabutylphosphonium Iodide as Interfacial Additive between Tio2 and Ch3nh3pbi3 in Mesoscopic Perovskite Solar Cells. Available at SSRN: https://ssrn.com/abstract=4170575 or http://dx.doi.org/10.2139/ssrn.4170575, posted 23 Jul 2022) in view of Burschka et al (US 2016/0086739) as applied to claims 1, 3, 5, and 7-9 above, and further in view of Zhan et al (US 2015/0380169).
Regarding claim 2 modified Valadez-Villalobos discloses the electron carrier of claim 1, but does not explicitly disclose wherein the metal oxide nanoparticles comprise an oxide of a metal comprising at least one or two selected from tin (Sn), zirconium (Zr), strontium (Sr), zinc (Zn), vanadium (V), molybdenum (Mo), tungsten (W), niobium (Nb), aluminum (Al) and gallium (Ga).
Zhan discloses a mesoporous titanium oxide electron transport layer for a perovskite solar cell further comprising aluminum oxide coatings (Zhan, [0044] Fig. 3 see: mesoporous layer of TiO2 nanoparticles with Al2O3 coating layers) that also assist in passivating surface traps at the titanium oxide surface (Zhan, [0044]).
Zhan and Valadez-Villalobos are combinable as they are both concerned with perovskite solar cells.
It would have been obvious to one having ordinary skill in the art at the time of the invention to modify the electron carrier of Valadez-Villalobos in view of Zhan such that the metal oxide nanoparticles of Valadez-Villalobos comprise aluminum oxide coatings as in Zhan (Zhan, [0044] Fig. 3 see: mesoporous layer of TiO2 nanoparticles with Al2O3 coating layers) as Zhan teaches they assist in passivating surface traps at the titanium oxide surface (Zhan, [0044]).
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Valadez-Villalobos et al (Effect of Tetrabutylphosphonium Iodide as Interfacial Additive between Tio2 and Ch3nh3pbi3 in Mesoscopic Perovskite Solar Cells. Available at SSRN: https://ssrn.com/abstract=4170575 or http://dx.doi.org/10.2139/ssrn.4170575, posted 23 Jul 2022) in view of Burschka et al (US 2016/0086739) as applied to claims 1, 3, 5, and 7-9 above, and further in view of Lee et al (Work-Function-Tunable Electron Transport Layer of Molecule Capped Metal Oxide for a High-Efficiency and Stable p−i−n Perovskite Solar Cell, ACS Appl. Mater. Interfaces 2020, 12, 45936−45949).
Regarding claim 6 modified Valadez-Villalobos discloses the coating agent of claim 5, but it’s not clear Valadez-Villalobos explicitly discloses wherein the coating agent comprises 0.30 to 2.00 wt% of the electron carrier and the remainder of the organic solvent.
However, such a weight concentration of an electron carrier with respect to the organic solvent in an organic carrier in known, Lee teaches providing an electron carrier in an organic solvent for forming an electron transport layer within the claimed range (Lee, see “Preparation of the Tetraalkylammonium Hydroxide Capped Metal Oxide NP Suspension” under methods on page 45946 see: TBAOH−metal oxide NP at a concentration of 10 mg/mL in ethanol (density 789 mg/ml) and thus at a ~1.25 wt% concentration [(10/(789+10))] ).
Lee and Valadez-Villalobos are combinable as they are both concerned with perovskite solar cells.
It would have been obvious to one having ordinary skill in the art at the time of the invention to modify the coating agent of Valadez-Villalobos in view of Lee such that the coating agent comprises 0.30 to 2.00 wt% of the electron carrier and the remainder of the organic solvent as in Lee (Lee, see “Preparation of the Tetraalkylammonium Hydroxide Capped Metal Oxide NP Suspension” under methods on page 45946 see: TBAOH−metal oxide NP at a concentration of 10 mg/mL in ethanol (density 789 mg/ml) and thus at a ~1.25 wt% concentration [(10/(789+10))] ) as such a modification would have amounted to the selection of a known concentration of the electron carrier with respect to the solvent in forming the electron transport layer.
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 ANDREW J GOLDEN whose telephone number is (571)270-7935. The examiner can normally be reached 11am-8pm.
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ANDREW J. GOLDEN
Primary Examiner
Art Unit 1726
/ANDREW J GOLDEN/Primary Examiner, Art Unit 1726
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