DETAILED ACTION
This is the fourth Office Action regarding application number 18/222,944, filed on 07/17/2023, which claims priority to provisional application number 63/389,873, filed on 07/16/2022.
This action is in response to the Applicant’s Response received 05/18/2026.
Status of Claims
Claims 1-8 and 10-29 are currently pending.
Claim 9 is canceled.
Claims 28 and 29 are amended.
Claims 14 and 25 are withdrawn.
Claims 1-8, 10-13, 15-24, and 26-29 are examined below.
No claim is allowed.
Response to Arguments
The Applicant’s arguments received 05/18/2026 have been carefully considered but they are not found persuasive. In the case of claim 29, the arguments are considered moot as the amended claim necessitated a new ground of rejection.
The applicant first argues that the YONG reference only discusses theoretical use of graphene-based materials in D-A heterojunctions and does not demonstrate use of GNRs as photoactive materials. Remarks 9. The applicant also asserts that “graphene and GNRs are not interchangeable--graphene is a conductor that does not have a bandgap.” Id. The examiner respectfully disagrees with the applicant’s position that these are distinctions that indicate non-obviousness. First, YONG focuses primarily on GNRs as a graphene material that is known to be semiconducting (pg. 314). A substantial part of page 316 is dedicated entirely to discussion explaining the utility of GNRs as a graphene-based photoactive material having a controllable bandgap and crystallographic orientation. The examiner does not understand YONG to not disclose GNRs as a photoactive material in its D-A heterojunctions. The examiner requests the applicant to clarify exactly what it means when it says that YONG’s devices only include graphene rather than GNRs-- YONG does not disclose any other graphene-based photoactive materials having a bandgap other than GNRs. The examiner requests a declaration from the inventor on this point so that the written record is clear.
TANG is relied upon in the rejections with respect to known teachings of EQE. The applicant next argues that TANG’s GNRs function only as an energy barrier and not a photoactive role, and further asserts that TANG does not show a GNR contribution. Remarks 9. As the examiner states above, YONG already teaches and suggests the use of GNRs as photoactive materials. As far as EQE is concerned, the examiner establishes that the presence of GNRs would be expected to produce the recited EQE contribution, because of the known advantages of GNRs such as improved stability. TANG also includes the GNRs as being considered within the “active layers” (see e.g., pg. 99: “C60:SWCNT:GNR active layers” and “C60:SWCNT:GNR photoactive layer”). Because both YONG and TANG describe GNRs used as photoactive layers, the examiner is unable to concur with the applicant’s position at this time, but the applicant should submit additional information that it believes may be important to this aspect.
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 of this title, 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 set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied 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 1-6, 10, 11, 15-21, 23, 24, and 26 are rejected under 35 U.S.C. 103 as being unpatentable over YONG (“Theoretical Efficiency of Nanostructured Graphene-Based Photovoltaics”) in view of TANG (“Flexible all-carbon photovoltaics with improved thermal stability”).
Regarding claim 1, YONG teaches a photovoltaic device comprising:
a substrate (flexible substrates discussed in Conclusions section);
a first electrode (cathode) on a surface of the substrate;
a second electrode (anode); and
a first photoactive layer between the first electrode and the second electrode, the first photoactive layer including graphene nanoribbons (GNRs) (graphene-based D-A HJ layer, GNRs described as appropriate materials for their adjustable optical and photo-responsive properties, pg. 316).
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YONG further describes that its organic PVs are compatible with flexible substrates. Accordingly, the office determines that skilled artisans would have considered it obvious to add a flexible substrate because substrates serve the important function of structurally supporting the very thin and fragile material layers comprising the optoelectronic device.
YONG does not disclose expressly that the GNRs have an external quantum efficiency (EQE) of greater than or equal to 0.5%. Here, the examiner believes the applicant may have intended to recite that the photovoltaic device has an EQE of ≥0.5%, as EQE is generally understood within the art to mean the measure of how efficiently dissociated electron-hole pairs are collected at opposite electrodes.
TANG teaches that the addition of GNRs to a photovoltaic device cause the EQE to be improved, with values over 25% (see Figs. 6a and 6b). TANG reports that the incorporation of GNRs within a photovoltaic device generates numerous positive effects, such as improved thermal and mechanical stability, and significantly improved response across the visible to NIR range (pgs. 99-100).
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Skilled artisans would have found it obvious to modify YONG and to have achieved increases in EQE via the GNRs because this produces an improved photovoltaic device having desirable electrical output, thermal and mechanical stability as taught by TANG. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. MPEP 2144.05. Here, the claimed EQE range of ≥0.5% overlaps with the range disclosed by the prior art references, and is prima facie obvious.
Regarding claim 2, modified YONG teaches the photovoltaic device of claim 1, wherein the first photoactive layer is neat ("neat" means effectively uniform in composition (as opposed to doped or mixed) and/or that the material is deposited only of itself) (YONG describes basic graphene nanoribbons, which are understood by their default chemical structure as not having any dopants or other mixed components; while chemical functionalization is an option to try, it is not described by YONG to be absolutely necessary; thus “neat” is described by YONG and would also be obvious to try since the photoactive layer is either neat or not neat--two finite options).
Regarding claim 3, modified YONG teaches the photovoltaic device of claim 1, wherein the first photoactive layer includes a first photoactive material including GNRs and a second photoactive material (YONG discusses that the photoactive layer is a “graphene-based D-A HJ layer”, thus there are two dissimilar materials because a heterojunction implies to chemically distinct compositions; if each is either a donor or an acceptor, then they are both photoactive).
Regarding claim 4, modified YONG teaches the photovoltaic device of claim 1, wherein the first photoactive layer defines a thickness ranging from 2 nm to 1000 nm (YONG, Fig. 3 describes thicknesses of 0-1000nm).
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Regarding claim 5, modified YONG teaches the photovoltaic device of claim 1, wherein the GNR is a semiconductor (GNRs are semiconducting, YONG, pg. 316).
Regarding claim 6, modified YONG teaches the photovoltaic device of claim 1, wherein at least a portion of the GNRs include edge groups (YONG describes grafted atoms and molecules along the edges, YONG, pg. 316).
Regarding claim 10, modified YONG teaches the photovoltaic device of claim 1, further comprising: a second photoactive layer (YONG discusses that the photoactive layer is a “graphene-based D-A HJ layer”, thus there are two dissimilar materials because a heterojunction implies to chemically distinct compositions; if each is either a donor or an acceptor, then they are both photoactive).
Regarding claim 11, modified YONG teaches the photovoltaic device of claim 10, wherein the second photoactive layer defines a thickness ranging from 5 nm to 200 nm (YONG explains photoactive layer thicknesses of about 100nm are the state of the art, pg. 315 and Fig. 3).
Regarding claim 15, modified YONG teaches the photovoltaic device of claim 1, wherein the first photoactive layer consists essentially of GNRs (YONG does not disclose that anything else comprises the first component of the photoactive layer, and the examiner construes only the GNRs as the first photoactive layer).
Regarding claim 16, modified YONG teaches the photovoltaic device of claim 1, wherein the first photoactive layer has an exciton diffusion length ranging from 10 nm to 300 nm (GNRs would be expected by skilled artisans to possess the claimed exciton diffusion length range because this is a property connected to its physical and chemical structure rather than something that can be modified without altering the substance itself).
Regarding product and apparatus claims, when the structure recited in the reference is substantially identical to that of the claims, claimed properties or functions are presumed to be inherent. It is well settled that where there is a reason to believe that a functional characteristic would be inherent in the prior art, the burden of proof then shifts to the applicant to provide objective evidence to the contrary. In re Schreiber, 128 F.3d at 1478, 44 USPQ2d at 1478, 44 USPQ2d at 1432 (Fed. Cir. 1997) (see MPEP 2112.01).
Since the examiner does not have proper means to conduct experiments, the burden of proof is now shifted to applicants to show otherwise. In re Best, 562 F.2d 1252, 195 USPQ 430 (CCPA 1977); In re Fitzgerald, 205 USPQ 594 (CCPA 1980).
Regarding claim 17, modified YONG teaches the photovoltaic device of claim 1, wherein the first photoactive layer has a charge collection length ranging from 10 nm to 10,000 nm (GNRs would be expected by skilled artisans to possess the claimed charge collection length range because this is a property connected to its physical and chemical structure rather than something that can be modified without altering the substance itself).
Regarding product and apparatus claims, when the structure recited in the reference is substantially identical to that of the claims, claimed properties or functions are presumed to be inherent. It is well settled that where there is a reason to believe that a functional characteristic would be inherent in the prior art, the burden of proof then shifts to the applicant to provide objective evidence to the contrary. In re Schreiber, 128 F.3d at 1478, 44 USPQ2d at 1478, 44 USPQ2d at 1432 (Fed. Cir. 1997) (see MPEP 2112.01).
Since the examiner does not have proper means to conduct experiments, the burden of proof is now shifted to applicants to show otherwise. In re Best, 562 F.2d 1252, 195 USPQ 430 (CCPA 1977); In re Fitzgerald, 205 USPQ 594 (CCPA 1980).
Regarding claim 18, modified YONG teaches the photovoltaic device of claim 1, wherein the GNRs define an average length ranging from 1 nm to 100,000 nm (prior art describes GNRs as having this general dimensional range, and it would be obvious to produce GNRs having this length range).
Regarding product and apparatus claims, when the structure recited in the reference is substantially identical to that of the claims, claimed properties or functions are presumed to be inherent. It is well settled that where there is a reason to believe that a functional characteristic would be inherent in the prior art, the burden of proof then shifts to the applicant to provide objective evidence to the contrary. In re Schreiber, 128 F.3d at 1478, 44 USPQ2d at 1478, 44 USPQ2d at 1432 (Fed. Cir. 1997) (see MPEP 2112.01).
Since the examiner does not have proper means to conduct experiments, the burden of proof is now shifted to applicants to show otherwise. In re Best, 562 F.2d 1252, 195 USPQ 430 (CCPA 1977); In re Fitzgerald, 205 USPQ 594 (CCPA 1980).
Regarding claim 19, modified YONG teaches the photovoltaic device of claim 1, wherein the GNRs define a core average width of 0.25 nm to 100 nm ("core width" means width not including edge or solubilizing groups) (GNRs would be expected by skilled artisans to possess the claimed core average width range because this is a property connected to its physical and chemical structure rather than something that can be modified without altering the substance itself).
Regarding product and apparatus claims, when the structure recited in the reference is substantially identical to that of the claims, claimed properties or functions are presumed to be inherent. It is well settled that where there is a reason to believe that a functional characteristic would be inherent in the prior art, the burden of proof then shifts to the applicant to provide objective evidence to the contrary. In re Schreiber, 128 F.3d at 1478, 44 USPQ2d at 1478, 44 USPQ2d at 1432 (Fed. Cir. 1997) (see MPEP 2112.01).
Since the examiner does not have proper means to conduct experiments, the burden of proof is now shifted to applicants to show otherwise. In re Best, 562 F.2d 1252, 195 USPQ 430 (CCPA 1977); In re Fitzgerald, 205 USPQ 594 (CCPA 1980).
Regarding claim 20, modified YONG teaches the photovoltaic device of claim 1, wherein the GNRs have a bandgap of greater than or equal to 0.1 eV (“The use of graphene as a photoactive material in OPV devices requires an optimum bandgap of =1.4 to 1.9 eV. A bandgap and its band position can be induced/tuned via chemical functionalization [41] (with a feasible induced-bandgap as large as =4.9 eV,[42] and the size of the gap can be controlled by varying the amount of chemically grafted atoms or molecules on the graphene surface and edges) or by using sub-10-nm GNRs”).
Regarding claim 21, modified YONG teaches the photovoltaic device of claim 1, wherein the GNRs have a bandgap of greater than or equal to 0.2 eV to less than or equal to 2.5 eV (“The use of graphene as a photoactive material in OPV devices requires an optimum bandgap of =1.4 to 1.9 eV. A bandgap and its band position can be induced/tuned via chemical functionalization [41] (with a feasible induced-bandgap as large as =4.9 eV,[42] and the size of the gap can be controlled by varying the amount of chemically grafted atoms or molecules on the graphene surface and edges) or by using sub-10-nm GNRs”). Overlapping ranges are prima facie obvious.
Regarding claim 23, modified YONG teaches the photovoltaic device of claim 1, wherein each of the GNRs defines a length and a width, each of the GNRs includes a quantity of benzene rings across the width, and the quantity ranges from 1 to 100 benzene rings (“narrow graphene nanoribbons (GNRs) with width <10nm” is obvious and reads on this range).
Regarding claim 24, modified YONG teaches the photovoltaic device of claim 1, wherein greater than or equal to 50% of the GNRs are oriented within 20% of perpendicular to the substrate (the examiner finds that this is only a simple rearrangement of the device parts without material significance to the device, and would be prima facie obvious to modify as a matter of common design choice, MPEP 2144.04).
Regarding claim 26, modified YONG teaches the photovoltaic device of claim 1, further comprising: an adjunct layer including a hole transport layer, an electron blocking layer (Fig. 1 illustrates an electron blocking layer), a buffer layer, an electron transport layer, a hole blocking layer, an electron extraction or any combination thereof.
Claims 7 and 8 are rejected under 35 U.S.C. 103 as being unpatentable over YONG (“Theoretical Efficiency of Nanostructured Graphene-Based Photovoltaics”) and TANG (“Flexible all-carbon photovoltaics with improved thermal stability”) as applied to claim 1 above, and further in view of CERNEVICS (“Even–odd conductance effect in graphene nanoribbons induced by edge functionalization with aromatic molecules: basis for novel chemosensors”).
Regarding claims 7 and 8, YONG teaches the photovoltaic device of claim 6, but does not disclose expressly that the edge groups include hydrogen, a halogen, an alkyl chain, or a thiophene chain, or any combination thereof (claim 7), or that the edge groups include
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or any combination thereof, wherein R=H, CH3, CH2CH3, CH2CH2CH3, CH(CH3)2, C(CH3)3, or any combination thereof (claim 8).
CERNEVICS teaches that the recited edge groups may be added, and depending on whether the number of aromatic rings in the guest molecule at the GNR edge is even or odd, either constructive or destructive interference takes place and affects electron transport (pg. 680).
Skilled artisans would have found it obvious to modify YONG and add phenyl groups to the GNR edge groups in order to affect band gap and electron transport as taught by CERNEVICS.
Claims 12 and 13 are rejected under 35 U.S.C. 103 as being unpatentable over YONG (“Theoretical Efficiency of Nanostructured Graphene-Based Photovoltaics”) and TANG (“Flexible all-carbon photovoltaics with improved thermal stability”) as applied to claim 1 above, and further in view of OSELLA (“Graphene Nanoribbons as Low Band Gap Donor Materials for Organic Photovoltaics: Quantum Chemical Aided Design”)
Regarding claims 12 and 13, YONG teaches the photovoltaic device of claim 10, wherein the first photoactive layer is a donor layer, and the second photoactive layer is an acceptor layer (claim 12), and wherein second photoactive layer includes C60 (claim 13).
OSELLA is well-aware of the option to combine together GNRs and C60 for photovoltaics, and notes that GNRs are very compatible with common acceptors such as C60 fullerenes for solar energy.
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Skilled artisans would have found it obvious to modify YONG and add C60 as an acceptor because it was well-known that common acceptors included C60, and that together with GNRs it would be possible to create carbon-based nanoelectronics with the ability to carefully control and select the materials’ bandgaps.
Claim 22 is rejected under 35 U.S.C. 103 as being unpatentable over YONG (“Theoretical Efficiency of Nanostructured Graphene-Based Photovoltaics”) and TANG (“Flexible all-carbon photovoltaics with improved thermal stability”) as applied to claim 1 above, and further in view of WADHWA (“Effect of edge defects on band structure of zigzag graphene nanoribbons”).
Regarding claim 22, YONG teaches the photovoltaic device of claim 1, but does not disclose expressly that the GNRs have less than 1 edge defect per 1 nm of length.
WADHWA describes that edge defect concentrations affect the band structure of the material (a critical property of the GNR) and that the concentration is varied by change the ratio of sp3 to p2 hybridized carbon atoms (pg. 161416-1, right col.).
Skilled artisans would have found it obvious to modify YONG and adjust the concentration to values as low as possible, including to values within the claimed range, in order to fully control the band gap values by closely controlling the localization of charges at the edge states (WADHWA, pg. 161416-2).
Claim 27 is rejected under 35 U.S.C. 103 as being unpatentable over YONG (“Theoretical Efficiency of Nanostructured Graphene-Based Photovoltaics”) and TANG (“Flexible all-carbon photovoltaics with improved thermal stability”) as applied to claim 26 above, and further in view of FUJIMORI (US 2002/0108649 A1).
Regarding claim 27, YONG teaches the photovoltaic device of claim 26, but does not disclose expressly that the adjunct layer includes a hole transport layer, and an electron transport layer.
FUJIMORI describes that electron transport and hole transport layers are important for organic solar cells because they allow the electrons and holes to more efficiently move to the electrodes, which is very important for the operation of a solar cell.
Skilled artisans would have found it obvious to modify YONG and add an electron transport layer and a hole transport layer as taught by FUJIMORI in order to enhance the operation of the device.
Claim 28 is rejected under 35 U.S.C. 103 as being unpatentable over YONG (“Theoretical Efficiency of Nanostructured Graphene-Based Photovoltaics”) in view of FUJIMORI (US 2002/0108649 A1) and OSELLA (“Graphene Nanoribbons as Low Band Gap Donor Materials for Organic Photovoltaics: Quantum Chemical Aided Design”).
Regarding claim 28, YONG teaches a photovoltaic device comprising:
a first electrode (cathode);
a second electrode (anode);
a donor layer between the first electrode and the second electrode, the donor layer including graphene nanoribbons (GNRs) and an acceptor layer between the donor layer and the second electrode (graphene-based D-A HJ layer, GNRs described as appropriate materials for their adjustable optical and photo-responsive properties, pg. 316; GNRs may be described as donors).
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YONG does not disclose expressly a hole transport layer between the donor layer and the first electrode; and an electron transport layer between the acceptor layer and the second electrode, or that the GNRs have absorption past 1000 nm (~1.23 eV).
FUJIMORI describes that electron transport and hole transport layers are important for organic solar cells because they allow the electrons and holes to more efficiently move to the electrodes, which is very important for the operation of a solar cell.
Skilled artisans would have found it obvious to modify YONG and add an electron transport layer and a hole transport layer as taught by FUJIMORI in order to enhance the operation of the device.
The examiner first asserts that YONG teaches photovoltaic devices having GNR bandgaps of “≈1.4 eV” as an optimum bandgap. The examiner notes that “≈” means “almost equal to”. The claim recites essentially that the GNRs have a bandgap of at least as low as about 1.23 eV. The examiner determines that “almost equal to 1.4 eV” reads on and is also substantially close to the claimed wavelength absorption range.
Additionally, OSELLA provides skilled artisans further direction and advice to build photovoltaic devices and use engineering judgement to consider band gap values down to 1.2 eV for higher photoconversion efficiencies (pg. 5545, left col., para. 1). 1.2 eV corresponds to a wavelength of 1033 nm.
Skilled artisans would have found it obvious to modify YONG and adjust the GNRs to have absorption past 1000 nm and band gap values down to 1.2 eV because these optical parameters also provide for higher photoconversion efficiencies as taught by OSELLA. The totality of the prior art evidence would naturally lead skilled artisans to comprehend that YONG is not teachings any sort of rigid rule for a bandgap lower bound, and that the prior art references together are suggestive of flexibility in the band gap design criteria and depends on the desired absorption profile, and that venturing to lower band gap values likely generates more electrical power.
Claim 29 is rejected under 35 U.S.C. 103 as being unpatentable over TANG (“Flexible all-carbon photovoltaics with improved thermal stability”; Supporting Information document also included) in view of LI (“Chemically Derived, Ultrasmooth Graphene Nanoribbon Semiconductors”).
Regarding claim 29, TANG teaches a photovoltaic device (Fig. S3, Supporting Information) comprising:
a substrate (glass);
a first electrode (ITO) on a surface of the substrate;
a second electrode (silver); and
a photoactive layer between the first electrode and the second electrode (“C60:SWCNT:GNR photoactive layer”), the first photoactive layer including a photoactive material, the photoactive material including graphene nanoribbons (GNRs) (“C60:SWCNT:GNR photoactive layer”), the photovoltaic device having an open circuit voltage of greater than or equal to 0.1 V (Fig. 6a shows an open circuit voltage V-OC of 0.51 V at zero current, overlapping with the claimed range). TANG teaches known GNR widths of between 0 to 140nm, with 50nm appears to be a critical width at which EQE saturates (Fig. 6b and pg. 100, left. col.).
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TANG does not disclose expressly that the GNRs have a bandgap of 0.1-1.3 eV.
LI teaches semiconducting GNRs and explores the width-bandgap relationship, explaining that the bandgap relationship appears to be Eg=0.8/[w (nm)] (this equation is a line fit of experimental data, not a fundamental equation). That is, GNR widths below about 8nm will have bandgaps within the claimed range.
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Skilled artisans would have found it obvious to modify the GNRs to have bandgaps within the range claimed, including to values such as 0.1-1.3 eV, because they are the bandgap values that correspond to the GNR widths recommended by TANG according to experimental line fit described by LI, where both references discuss that GNRs having certain widths produce a semiconductor material with an observable bandgap with a reasonable expectation of success. MPEP 2143.
Conclusion
No claim is allowed.
The 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). The Applicant is reminded of the extension of time policy as set forth in 37 C.F.R. § 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 extension fee 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.
Contact Information
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ANGELO TRIVISONNO whose telephone number is (571) 272-5201 or by email at <angelo.trivisonno@uspto.gov>. The examiner can normally be reached on MONDAY-FRIDAY, 9:00a-5:00pm EST. The examiner's supervisor, NIKI BAKHTIARI, can be reached at (571) 272-3433.
/ANGELO TRIVISONNO/
Primary Examiner
Prosecution Insights