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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 10 April 2026 has been entered.
Status of Claims
Claims 1 and 5-10 as amended in applicant’s response dated 10 April 2026 are presently under consideration. Claims 2-4 remain cancelled and claims 11-14 remain withdrawn from consideration.
Applicant’s amendments to the claims have overcome the prior art rejection of record, but upon further search and consideration of applicant’s newly amended claims new prior art was uncovered and a new grounds of rejection is set forth below.
Upon further consideration of the claims new issues of indefiniteness under 35 U.S.C. 112(b) in the claims are identified below.
Applicant’s arguments and remarks where applicable are addressed below.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1, and 5-10 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 1 recites “a molar ratio of the lithium and the material of the hole transport layer” and although it’s inherent that the hole transport layer includes at least one material, it’s not inherent that it only contains only one material and thus it’s not clear what particular material of the hole transport layer is being referenced in this recitation as no singular hole transport material was previously defined in the claim and thus it’s unclear what particular material is being referenced. As such, the scope of claim 1 cannot be reasonably determined and is rendered indefinite.
Claims 5-10 are also rendered indefinite by depending from indefinite claim 1.
Claim 8 recites the hole transport layer contains Spiro-OMeTAD where it’s unclear if Spiro-OMeTAD is further in addition to the hole transport material recited in claim 1 or if claim 8 means to claim Spiro-OMeTAD as the hole transport material previously recited in claim 1. As such, the scope of claim 8 cannot be reasonably determined and is rendered indefinite.
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.
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.
Claims 1, 5, and 7-10 are rejected under 35 U.S.C. 103 as being unpatentable over Mishima et al (US 2018/0019361) and further in view of Forward et al (“Protocol for Quantifying the Doping of Organic Hole-Transport Materials”, ACS Energy Letters, Vol 4, pages 2547-2551, September 30, 2019 ) or alternatively in further view of Kong et al (CO2 doping of organic interlayers for perovskite solar cells, Nature, Vol 594, pg. 51–56, 3 June 2021).
Regarding claim 1 Mishima discloses a photoelectric conversion element comprising:
a light absorbing layer ([0024], Fig. 1 see: light absorbing layer 12);
a hole transport layer that transports holes generated by photoexcitation of the light absorbing layer ([0024], [0032] Fig. 1 see: hole transporting layer 12); and
a transparent conductive layer that is in contact with the hole transport layer and receives the holes from the hole transport layer ([0022], Fig. 1 see: light-receiving-side transparent electroconductive layer 3 contacting hole transporting layer 12),
wherein a carrier density of the transparent conductive layer is more than 1×1016 cm−3 and 1×1020 cm−3 or less ([0044] see: the carrier density of the light-receiving-side transparent electroconductive layer 3 is preferably 1×1019 to 5×1020 cm−3 and further preferably 1×1020 cm−3 or less and thus discloses a preferable range of 1×1019 to 1×1020 cm−3),
wherein the hole transport layer contains an additive that oxidizes the hole transport layer to increase the carrier density of the hole transport layer ([0033] see: hole transporting layer may contain an additive for reducing the resistivity such as Li-bis(trifluoromethanesulfonyl)imide (Li-TFSI), Li-TFSI increases conductivity by facilitating oxidation of the hole transport material), and
the additive contains lithium ([0033] see: hole transporting layer may contain an additive for reducing the resistivity such as Li-bis(trifluoromethanesulfonyl)imide (Li-TFSI)).
Mishima does not explicitly disclose a molar ratio of lithium and the material of the hole transport layer is 0.6 or more.
Forward discloses efficiency of the perovskite solar cell varies based on the molar ratio of lithium and the material of the hole transport layer in Fig. 1(a) (see Fig. 1a including one example with a mol% LiTFSI as over 60 mol%). Forward further discloses in the column bridging pages 2549-2550 that the conductivity and carrier density increases with increasing LiTFSI.
As such, given that light absorption increases with increasing Li-TFSI concentration in the hole transporting layer (Mishima, [0033]) while conductivity of the hole transporting layer also increases with increasing Li-TFSI concentration (Forward, column bridging pages 2549-2550), these properties are thus result effective variables dependent on the concentration ratio between the material of the hole transport layer and the lithium in the hole transport layer.
As the light absorption and conductivity of the hole transporting layer are variables that can be modified, among others, by adjusting the concentration ratio between the material of the hole transport layer and the lithium in the hole transport layer, with the light absorption and conductivity of the hole transporting layer both increasing as the concentration of lithium (Li-TFSI) is increased, the precise concentration ratio would have been considered a result effective variable by one having ordinary skill in the art at the time the invention was made. As such, without showing unexpected results, the claimed concentration ratio between the material of the hole transport layer and the lithium in the hole transport layer cannot be considered critical. Accordingly, one of ordinary skill in the art at the time the invention was made would have optimized, by routine experimentation, the concentration ratio between the material of the hole transport layer and the lithium in the hole transport layer in the device of Mishima to obtain the desired balance between the light absorption and conductivity of the hole transporting layer (In re Boesch, 617 F.2d. 272, 205 USPQ 215 (CCPA 1980)), since it has been held that where the general conditions of the claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. (In re Aller, 105 USPQ 223).
In the alternative, Kong discloses a perovskite solar cell with a hole transport layer having a molar ratio of lithium and the material of the hole transport layer is 0.6 or more (Abstract and right column of page 54 see: mole ratio of spiro-OMeTAD to LiTFSI was 6 to 4 thus Li:spiro-OMeTAD is ~0.67:1). Kong discloses this CO2 treated spiro- OMeTAD:LiTFSI blend film provides a p-type doping with high conductivity compared to a pristine spiro-OMeTAD:LiTFSI film while realizing stable, high-efficiency perovskite solar cells without any post-treatments (Kong, see Abstract).
Kong and Mishima are combinable as they are both concerned with the field of 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 device of Mishima in view of Kong such that the hole transport layer of Mishima has a molar ratio of lithium and the material of the hole transport layer is 0.6 or more and is CO2 treated as in Kong (Abstract and right column of page 54 see: mole ratio of spiro-OMeTAD to LiTFSI was 6 to 4 thus Li:spiro-OMeTAD is ~0.67:1) as Kong discloses this CO2 treated spiro- OMeTAD:LiTFSI blend film provides a p-type doping with high conductivity compared to a pristine spiro-OMeTAD:LiTFSI film while realizing stable, high-efficiency perovskite solar cells without any post-treatments (Kong, see Abstract).
Regarding claim 5 modified Mishima discloses the photoelectric conversion element according to claim 1, wherein the additive is lithium (fluorosulfonyl)(trifluoromethyl)imide (LiTFSI) ([0033] see: hole transporting layer may contain an additive for reducing the resistivity such as Li-bis(trifluoromethanesulfonyl)imide (Li-TFSI)).
Regarding claim 7 modified Mishima discloses the photoelectric conversion element according to claim 1, wherein a thickness of the hole transport layer is 130 nm or less ([0035] see: the thickness t of the hole transporting layer 12 is preferably 100 nm or less).
Regarding claim 8 modified Mishima discloses the photoelectric conversion element according to claim 1, wherein the transparent conductive layer is formed of a metal oxide containing any of indium, zinc, and tin ([0039] see: the transparent electroconductive layer 3 is zinc oxide, indium oxide and tin oxide used alone or in complex oxide with indium-based oxides including indium oxide being preferable), and the hole transport layer contains Spiro-OMeTAD ([0032] see: hole transporting layer is for example Spiro-OMeTAD).
Regarding claim 9 modified Mishima discloses the photoelectric conversion element according to claim 1, wherein the light absorbing layer contains a compound having a perovskite structure ([0024], [0029] Fig. 1 see: The first photoelectric conversion unit 1 is a perovskite-type photoelectric conversion unit, and contains a photosensitive material (perovskite crystal material) of perovskite-type crystal structure in the light absorbing layer 11).
Regarding claim 10 modified Mishima discloses the photoelectric conversion element according to claim 1, wherein the photoelectric conversion element is a solar cell stacked on a bottom cell of a multi-junction solar cell ([0022], Fig. 1 see: The first photoelectric conversion unit 1 is stacked on second photoelectric conversion unit 2 in tandem-type photoelectric conversion device 110).
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Mishima et al (US 2018/0019361) in view of Forward et al (“Protocol for Quantifying the Doping of Organic Hole-Transport Materials”, ACS Energy Letters, Vol 4, pages 2547-2551, September 30, 2019 ) or alternatively in view of Kong et al (CO2 doping of organic interlayers for perovskite solar cells, Nature, Vol 594, pg. 51–56, 3 June 2021) as applied to claims 1, 5, and 7-10 above, and further in view of Li et al (Insights into the hole transport properties of LiTFSI-doped spiro-OMeTAD films through impedance spectroscopy, J. Appl. Phys. 128, 085501 (2020)).
Regarding claim 6 modified Mishima discloses the photoelectric conversion element according to claim 1, but does not explicitly disclose wherein the carrier density of the hole transport layer is 1×1018 cm−3 or more.
Li teaches a perovskite solar cell with a hole transport layer of spiro-OMeTAD doped with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) where the LiTFSI doped spiro-OMeTAD has a carrier density of 1×1018 cm−3 or more (Li, Abstract, left column of page 085501-4, see: hole carrier density of 2.80×1019cm−3 for LiTFSI-doped spiro-OMeTAD films). Li teaches this enhances hole mobility in the spiro-OMeTAD layer and improves power conversion efficiency in the solar cell (See Conclusion and Table II on page 085501-7).
Li and Mishima are combinable as they are both concerned with the field of solar cells.
It would have been obvious to one having ordinary skill in the art at the time of the invention to modify the device of Mishima in view of Li such that the carrier density of the hole transport layer of Mishima is 1×1018 cm−3 or more as in Li (Li, Abstract, left column of page 085501-4, see: hole carrier density of 2.80×1019cm−3 for LiTFSI-doped spiro-OMeTAD films) as Li teaches this enhances hole mobility in the spiro-OMeTAD layer and improves power conversion efficiency in the solar cell (See Conclusion and Table II on page 085501-7).
Response to Arguments
Applicant's arguments filed 10 April 2026 have been fully considered but they are not persuasive.
Applicant argues unexpected results of the claimed molar ratio of lithium and the material of the hole transport layer is 0.6 or more, but these alleged unexpected results are not commensurate in scope with the limitations of claim 1. Claim 1 recites “a molar ratio of lithium and the material of the hole transport layer is 0.6 or more” but does not specify the material of the hole transport layer in the claims where the examples in Table 2 are limited to specifically a molar ratio for Li provided as Li-TFSI and a hole transport material of Spiro-OMeTAD. None of these features are specifically recited in claim 1 and there is no evidence presented that the claimed molar ratio will provide the improvements for hole transport material beyond Spiro-OMeTAD. For these reasons, applicant’s arguments to unexpected results are not found persuasive.
Applicant’s further arguments with respect to claims 1 and 5-10 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.
Conclusion
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ANDREW J. GOLDEN
Primary Examiner
Art Unit 1726
/ANDREW J GOLDEN/Primary Examiner, Art Unit 1726
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