DETAILED ACTION
This is the third 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 11/06/2025.
Status of Claims
Claims 1-8 and 10-29 are currently pending.
Claim 9 is cancelled.
Claims 1, 28, and 29 are amended.
Claims 14 and 25 are withdrawn.
Claims 1-8, 10-13, 15-24, and 26-29 are examined below.
The rejection of claims under 35 U.S.C. § 112 has been withdrawn in light of the Applicant’s amendments.
The rejection of claim 29 under 35 U.S.C. § 102 has been withdrawn in light of the Applicant’s amendments.
Upon further examination, the Office has set forth a new ground of rejection.
No claim is allowed.
Response to Arguments
The Applicant’s arguments received 11/06/2025 have been carefully considered but they are not found persuasive at this time.
The applicant first argues that photodetectors do not have an open circuit voltage, thus YU cannot disclose the invention recited in claim 29. The examiner does not find the applicant’s remark compelling, as peer reviewed literature describes photodetectors having open-circuit voltage (see, e.g., abstract, “Light Detection in Open-Circuit Voltage Mode of Organic Photodetectors,” stating that “the open-circuit voltage regime of organic photodetectors is shown to be efficient for detecting low light signals.”) The examiner respectfully requests a detailed explanation by an inventor supporting the applicant’s distinction between photodetectors and photovoltaic devices as it relates to open-circuit voltage. The examiner expresses additional concern that the applicant’s argument affects the scope and claim interpretation of claim 29, since it would not be well-understood by a skilled artisan exactly how the preamble term reciting a photovoltaic device differentiates a device having all of the recited elements (substrate, electrodes, photoactive layers, etc.). The examiner requests further detailed discussion from the applicant elaborating the intended meaning of claim 29. The rejection of claim 29 is modified to address the newly recited claim limitation requiring a certain open-circuit voltage minimum.
The applicant next asserts that YONG in view of TANG does not disclose the recited GNR contribution to EQE range required by claim 1. The applicant also asserts that YONG does not demonstrate use of GNRs as photoactive materials, and that TANG does not disclose the use of GNRs in “a photoactive role”. The examiner declines to accept the applicant’s assertions at this time. First, YONG explicitly states that the GNRs are used in the donor-acceptor heterojunction, and the examiner included Figure 1 illustrating device structure showing the “Graphene-based D-A HJ layer”. The examiner requests that the applicant provide additional explanation of its position, as YONG appears to expressly “demonstrate use of GNRs as photoactive materials”.
Similarly, in its supplemental materials describing its photovoltaic device, TANG describes the GNR materials within the photoactive junction (Figure S3(a), also below). TANG also explains on page 100 that “GNRs provides an additional energy barrier to dissociation and thereby significantly improves the stability”--the examiner asserts that providing an additional energy barrier is a photoactive role. The examiner respectfully requests a detailed explanation by an inventor supporting the applicant’s contention that the GNRs have no role in the conversion of light to electricity in TANG’s device.
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The examiner concludes that TANG’s description of the GNRs providing an EQE increase is sufficiently descriptive and suggestive, and reads on the claimed limitation and EQE value range of claim 1.
The applicant finally argues that OSELLA does not cure YONG’s deficiencies with respect to GNRs having absorption past 950 nm. Although the Office action presents the necessary elements establishing a prima facie case of obviousness and cites specific passages of OSELLA, the applicant does not expressly disagree with any of the examiner’s specific factual findings, only stating in its summary conclusion that claim 28 is patentable. The examiner respectfully declines to agree with the applicant’s position, and notes that OSELLA encourages skilled artisans to use known methods to employ GNRs with absorption down to 1.2 eV or 1033 nm--values within the range claimed.
The examiner invites the applicant to arrange a telephone interview to discuss the status of this application and any possible amendments or other declarations that may move this application beyond the present rejections.
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 and TANG 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 and TANG 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 and TANG 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 and TANG 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 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 950 nm (~1.30 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 1.37 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 900 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 LEE (“An organic photovoltaic featuring graphene nanoribbons”) in view of OSELLA (“Graphene Nanoribbons as Low Band Gap Donor Materials for Organic Photovoltaics: Quantum Chemical Aided Design”).
Regarding claim 29, LEE teaches a photovoltaic device comprising:
a substrate (glass);
a first electrode (ITO) on a surface of the substrate;
a second electrode (Ag); and
a first photoactive layer between the first electrode and the second electrode (GNR layer), the first photoactive layer including graphene nanoribbons (GNRs), the photovoltaic device having an open circuit voltage of greater than or equal to 0.1 V (Fig. 4a shows an open circuit voltage of about 0.75 V at zero current, overlapping with the claimed range). Figure 1b shows the bandgap of the GNRs to be 1.5 eV, which the examiner finds is close enough to the claimed range to generate substantially identical results. See Titanium Metals.
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LEE does not disclose expressly that the GNRs have a bandgap ranging from exactly 0.1 eV to 1.3 eV. Alternatively, OSELLA teaches that the bandgap of GNRs is highly adjustable, including to values of 1.08 eV (m-ANR), and that materials with band gap down to 1.2 eV is very important, and that GNRs are appealing (pg. 5545, left col.).
Skilled artisans would have found it obvious to modify the GNRs to have bandgaps with in the range claimed, including to values such as 1.08 eV, because they match well with the solar emission spectrum and “strongly absorb light across the visible and infrared spectral regions that should translate into efficient harvesting of the solar emission” as taught by OSELLA (pg. 5546, right col.).
Conclusion
No claim is allowed.
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