DETAILED ACTION
This is the first Office Action regarding application number 18/407,215, filed on 01/08/2024, which is a continuation of application number 16/994,369, filed on 08/14/2020, which claims priority to provisional application number 62/887,942, filed on 08/16/2019.
This action is in response to the Applicant’s Response received 07/10/2025.
Status of Claims
Claims 1-18 are currently pending.
Claims 1-18 are examined below.
No claim is allowed.
Election of Restricted Inventions
The Applicant’s election of Species A1 and B1 in the reply received on 07/10/2025 is acknowledged. The applicant traverses the requirement and acknowledges that the identified species are not patentably distinct, i.e., that the identified species are obvious variants. All of the applicant’s other traversal arguments are not considered and are moot.
The restriction requirement is withdrawn.
Examiner Comments
The examiner wishes to express its interpretation of certain terms used frequently in the claims and mentioned in the instant specification.
“Visible light” may refer to light within a wavelength range of 380nm-750nm or to narrower ranges of 450nm-650nm (para. 80).
“Visibly transparent” refers to a material that exhibits an overall/average/maximum absorption in the visible band within about 0%-70% (para. 81). Visibly transparent materials are generally considered at least partially see-through. The broadest available interpretation of this term includes a material having a maximum absorption of 70% within 450nm-650nm.
The instant specification also describes “semitransparent” as also apparently within the same range of 0%-70%, and does not provide any sort of narrower definition. The examiner applies an interpretation to this word where semitransparent is not fully 100% transparent.
“Color neutral” refers to a color of neutral tone that is close to white or gray colors. A device or material may be color neutral if it has CIELAB a* and b* values within -10 to 10. The applicant also describes a material as “color neutral” if the transmissivity at different wavelengths within the visible band are within 10% of the average visible transmissivity (apparently related and/or equivalent with absolute variation in transmission).
Color neutral is also described as having substantially equal r, g, and b values within the RGB color space (para. 83). The examiner wishes to note that the applicant also appears to use multiple color systems to describe color features.
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, 2, 4, 6-11, 13, and 15-18 are rejected under 35 U.S.C. 103 as being unpatentable over LEE (“Colored dual-functional photovoltaic cells”).
Regarding claims 1 and 10, LEE teaches a visibly transparent photovoltaic device and method of producing the same, comprising:
a visibly transparent substrate (glass); a first visibly transparent electrode (ITO) coupled to the visibly transparent substrate; a second visibly transparent electrode (Ag); a visibly transparent photoactive layer (a-Si; the examiner asserts that Fig. 5c supports a finding that the photoactive layer is visibly transparent because it can be seen as see-through) between the first visibly transparent electrode and the second visibly transparent electrode; and
an optical layer (WO3) disposed above the second visibly transparent electrode, having a material separate from the visibly transparent photoactive layer, the first visibly transparent electrode, and the second visibly transparent electrode, the visibly absorbing material,
wherein the optical layer has a thickness such that the visibly transparent substrate, the first visibly transparent electrode, the second visibly transparent electrode, the visibly transparent photoactive layer, and the visibly transparent photoactive layer together are characterized by transmitted CIE1931 values of (0.358, 0.360), close to the coordinate of the white light (0.33, 0.33) (see also Figs. 5c and 5d),
wherein the optical layer is not disposed between the first visibly transparent electrode and the second visibly transparent electrode (WO3 layer is disposed not between the two electrodes).
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LEE does not disclose expressly that the photoactive layer is configured to convert at least one of near-infrared (NIR) light or ultraviolet (UV) light into photocurrent and characterized by an absorption spectrum with a peak outside the visible spectrum in the NIR or UV spectrum. LEE also does not expressly describe absorption properties of the optical layer, or color information described using the CIELAB coordinate system. LEE does not expressly describe the WO3 optical layer as visibly absorbing.
LEE, in other parts of the reference, explains that skilled artisans should consider exploiting semiconductive materials have can selectively harvest UV and IR parts of the spectrum while transmitting the visible light spectrum, and that allows for capture of light invisible to the human eye while also leading to further increases in performance (pg. 10, right col., para. 1).
Skilled artisans would have found obvious the modification of LEE’s photoactive layer to instead be replaced with other useful semiconductive materials that can selectively harvest UV and/or IR parts of the spectrum while transmitting the visible light spectrum, to further increase performance.
Additionally, LEE describes that the device has a color characterized by transmitted CIE1931 values of (0.358, 0.360), close to the coordinate of the white light (0.33, 0.33). LEE further describes the device for “neutral-colored, semitransparent power-generating window applications,” and having high optical transparency. The examiner determines that sufficient evidence supports a finding that LEE’s device also has CIELAB a* and b* values within the claimed ranges because “neutral-colored” means colors within the claimed range of -10 to 10. The examiner is unmoved that simply describing identical devices using different color systems patentably distinguishes the prior art from the claimed invention, and in conclusion the examiner determines that the prior art renders the claimed device to be obvious.
The instant application does not expressly define the meaning of the term “visibly absorbing” or provide significant context on exactly how the term modifies the material or function of the claimed optical layer. On its face, the term would appear to be understood by skilled artisans simply to mean that some non-zero amount of light in the visible range is absorbed by the material.
The examiner asserts that WO3 absorbs a non-zero amount of light in the visible range. Alternatively, LEE also describes an optical layer that also includes a PTCBI layer attached to the WO3 layer (Fig. 7a). LEE reports that this arrangement is also useful for color control.
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Skilled artisans would have found it obvious to further modify LEE with its additional teachings to add PTCBI layers with the WO3 layer to form an optical layer having multiple sublayers because this is described as a suitable replacement for color control of the device. PTCBI is known to be visibly absorbing, and is known to have a different and complimenting absorption profile than other materials such as silicon or other UV/NIR absorbing materials.
Regarding claims 2 and 11, LEE teaches or would have suggested the visibly transparent photovoltaic device and method of claims 1 and 10, wherein the visibly transparent photovoltaic device is characterized by a flat transmission profile across the visible spectrum, having an absolute variation in transmission percentage of less than 30% between the wavelengths of 450 nm and 650 nm (transmittance stays between 50-80%, and thus reads on the claimed range, see Fig. 5c).
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Regarding claims 4 and 13, LEE teaches or would have suggested the visibly transparent photovoltaic device and method of claims 1 and 10, but does not disclose expressly that the thickness of the optical layer is set such that the visibly transparent photovoltaic device is characterized by the transmitted a* and b* values between -5 and 5 in the CIELAB color space.
LEE describes that the device has a color characterized by transmitted CIE1931 values of (0.358, 0.360), close to the coordinate of the white light (0.33, 0.33). LEE further describes the device for “neutral-colored, semitransparent power-generating window applications,” and having high optical transparency. The examiner determines that sufficient evidence supports a finding that LEE’s device also has CIELAB a* and b* values within the claimed ranges because “neutral-colored” means colors within the claimed range of -5 to 5. The examiner is unmoved that simply describing identical devices using different color systems patentably distinguishes the prior art from the claimed invention, and in conclusion the examiner determines that the prior art renders the claimed device to be obvious.
Regarding claims 6 and 15, LEE teaches or would have suggested the visibly transparent photovoltaic device and method of claims 1 and 10, wherein the optical layer is disposed above the second visibly transparent electrode (WO3 layer disposed above second visibly transparent electrode in illustrations above).
Regarding claims 7 and 16, LEE teaches or would have suggested the visibly transparent photovoltaic device and method of claims 1 and 10, but does not disclose expressly in a single embodiment a second visibly absorbing material characterized by a third absorption spectrum with a third peak in the visible spectrum, wherein the third absorption spectrum is complementary to the absorption spectrum and the second absorption spectrum. However, LEE encourages skilled artisans to consider employing optical layers comprising multiple colors (Fig. 7a) and that this is achievable simply by controlling the thickness of areas of the optical layers to generate complementary colors.
Skilled artisans would have found it obvious to modify LEE and add additional portions of absorbing materials having another absorption spectrum peak of another visible color, i.e., complementary, because then semitransparent colors can be produced easily only by selecting thicknesses of the optical layer material as taught by LEE. Additionally, adding a second visibly absorbing material is a modification not more than a duplication of parts without any unexpected result. MPEP 2144.04(VI)(B).
Regarding claims 8 and 17, LEE teaches or would have suggested the visibly transparent photovoltaic device and method of claims 1 and 10, wherein the optical layer does not contribute to photocurrent (WO3 is not understood to contribute to photocurrent and is not described as such in LEE).
Regarding claims 9 and 18, LEE teaches or would have suggested the visibly transparent photovoltaic device and method of claims 1 and 10, wherein the optical layer comprises at least one passive material (WO3 is interpreted as a passive material, such that it does not meaningfully contribute to electrical output).
Claims 3 and 12 are rejected under 35 U.S.C. 103 as being unpatentable over LEE (“Colored dual-functional photovoltaic cells”) as applied to claims 2 and 11 above, and further in view of CHEN (“Semi-transparent polymer solar cells with 6% PCE, 25% average visible transmittance and a color rendering index close to 100 for power generating window applications”).
Regarding claim 3, LEE teaches or would have suggested the visibly transparent photovoltaic device of claim 2, but does not disclose expressly that the absolute variation in transmission percentage is less than 10% between the wavelengths of 450 nm and 650 nm.
CHEN teaches a semitransparent polymer solar cell for power generating window applications that provide close to white or achromatic transparency, and include donor/acceptor polymer material for the photoactive layer (PBDTTT-C-T:PC71BM, pg. 9552). CHEN also describes that a suitable device construction yields desirable visual properties including a low absolute variation in transmission percentage, including values that appear to be less than 10% between 450-650nm (Fig. 2a).
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Skilled artisans would have found it obvious to modify LEE and replace the photoactive layer material with PBDTTT-C-T:PC71BM as donor and acceptor materials as taught by CHEN because this material is suitable for its intended use as a photoactive material yielding a near-white color useful for power generating window applications. This modification would yield a device having the recited absolute variation in transmission percentage.
Regarding claim 12, LEE teaches or would have suggested the visibly transparent photovoltaic device of claim 11, but does not disclose expressly that the visibly transparent photoactive layer includes a donor material and an acceptor material.
CHEN teaches a semitransparent polymer solar cell for power generating window applications that provide close to white or achromatic transparency, and include donor/acceptor polymer material for the photoactive layer (PBDTTT-C-T:PC71BM, pg. 9552).
Skilled artisans would have found it obvious to modify LEE and replace the photoactive layer material with PBDTTT-C-T:PC71BM as donor and acceptor materials as taught by CHEN because this material is suitable for its intended use as a photoactive material yielding a near-white color useful for power generating window applications.
Claims 5 and 14 are rejected under 35 U.S.C. 103 as being unpatentable over LEE (“Colored dual-functional photovoltaic cells”) in view of LOO (US 2018/0175313 A1).
Regarding claims 5 and 14, LEE teaches or would have suggested the visibly transparent photovoltaic device of claims 1 and 10, but does not disclose expressly that the visibly transparent photoactive layer includes a donor material and an acceptor material. LEE does, however, mention OPV cells and P3HT:PCBM as useful photoactive layers (pg. 2, right col.).
LOO teaches organic photovoltaic devices with donor and acceptor materials, particularly suited for applications where transparency in the visible light region is a key requirement, such as windows for buildings and for vehicles (para. 36). Organic donor and acceptor materials are increasingly desirable in a variety of applications because they are relatively inexpensive to construct, and provide desirable physical properties, such as flexibility, permitting their use in applications unsuitable for rigid materials (para. 4).
Skilled artisans would have found it obvious to modify LEE and replace the photoactive layer material with donor and acceptor materials because these are particularly well-suited for applications where transparency in the visible light region is a key requirement, such as windows for buildings and for vehicles as taught by LOO, due to their inexpensive cost and desirable physical properties.
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.
If attempts to reach the examiner by telephone are unsuccessful, the examiner's supervisor, ALLISON BOURKE, can be reached at (303) 297-4684.
/ANGELO TRIVISONNO/
Primary Examiner, Art Unit 1721