Berny, Stephane et al.Download PDFPatent Trials and Appeals BoardSep 9, 201914399009 - (D) (P.T.A.B. Sep. 9, 2019) Copy Citation UNITED STATES PATENT AND TRADEMARK OFFICE UNITED STATES DEPARTMENT OF COMMERCE United States Patent and Trademark Office Address: COMMISSIONER FOR PATENTS P.O. Box 1450 Alexandria, Virginia 22313-1450 www.uspto.gov APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO. 14/399,009 11/05/2014 Stephane Berny MERCK-4247 1064 23599 7590 09/09/2019 MILLEN, WHITE, ZELANO & BRANIGAN, P.C. 2200 CLARENDON BLVD. SUITE 1400 ARLINGTON, VA 22201 EXAMINER HAVLIN, ROBERT H ART UNIT PAPER NUMBER 1639 NOTIFICATION DATE DELIVERY MODE 09/09/2019 ELECTRONIC Please find below and/or attached an Office communication concerning this application or proceeding. The time period for reply, if any, is set in the attached communication. Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the following e-mail address(es): docketing@mwzb.com PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE ____________ BEFORE THE PATENT TRIAL AND APPEAL BOARD ____________ Ex parte STEPHANE BERNY, AMY PHILLIPS, PRITI TIWANA, TOBY CULL, MIGUEL CARRASCO-OROZCO, and NICOLAS BLOUIN ____________ Appeal 2019-003260 Application 14/399,009 Technology Center 1600 ____________ Before JEFFREY N. FREDMAN, DEBORAH KATZ, and JOHN G. NEW, Administrative Patent Judges. FREDMAN, Administrative Patent Judge. DECISION ON APPEAL This is an appeal1,2 under 35 U.S.C. § 134(a) involving claims to formulations for use in an electron transport layer (“ETL”) in an organic photovoltaic (“OPV”) device. The Examiner rejected the claims as obvious. We have jurisdiction under 35 U.S.C. § 6(b). We AFFIRM. 1 Appellants identify the Real Party in Interest as Merck Patent GmbH (see App. Br. 1). 2 We have considered and herein refer to the Specification of Nov. 5, 2014 (“Spec.”); Final Office Action of Mar. 13, 2018 (“Final Act.”); Appeal Brief of Oct. 29, 2018 (“App. Br.”); Examiner’s Answer of Jan. 28, 2019 (“Ans.”); and Reply Brief of Mar. 20, 2019 (“Reply Br.”). Appeal 2019-003260 Application 14/399,009 2 Statement of the Case Background OPVs may include interfacial materials enclosed between the photoactive film and one of the electrodes to improve the performance and lifetime of the devices (Spec. 1:12–18). ETLs are an example of an interfacial layer having electron transport properties (Spec. 1:30–32). ETLs may be incorporated into the regular structure of an OPV device (Spec. 4:1– 8). The regular structure of an OPV device may include, in order of deposition, a transparent electrode (anode), a hole transport layer, e.g., PEDOT:PSS, a photoactive layer, e.g., a bulk heterojunction (“BHJ”), an ETL, and an electrode (cathode) (id.). The prior art describes numerous materials used as ETLs in OPVs, including alkaline earth metals, metal oxides, semiconductors, dipole materials, polymer electrolytes, cationic or anionic polymers, and zwitterionic compounds (see id. at 4:10–8:26). However, these materials suffer from various drawbacks (id. 6:6–8). Therefore, the Specification asserts a need for “ETL materials which enable efficient charge transport from the photoactive layer to the cathode and lead to higher cell efficiencies, compared to materials from the prior art” (id. 6:13–16). The Claims Claims 1–4, 6, 7, 10, 24–26, 28, and 32 are on appeal. Independent claim 1 is representative and reads as follows: 1. An organic electronic device, which is or comprises an organic photovoltaic device (OPV), which device comprises: two electrodes, a photoactive layer and an electron transport layer (ETL) between the photoactive layer and an electrode, which organic photovoltaic device is a bulk heterojunction Appeal 2019-003260 Application 14/399,009 3 (BHJ) OPV device or inverted BHJ OPV device and comprises a bulk heterojunction, wherein the electron transport layer comprises or is made from a formulation comprising an organic salt, wherein the organic salt comp1ises a first ionic entity and a second counterionic entity, wherein: the first and second entities are small molecules, the first entity is an organic entity, comprising - a charged organic core comprising a single charged moiety or a plurality of charged moieties wherein the charged organic core comprises at least one moiety selected from the group consisting of: dialkylpyrrolidinium, mono or dialkylpyridinium, trialkylsulfonium, carbazolium, indolium, piperidinium, morpholinium, pyrimidinium, pyridazinium, pyrazinium, pyrazolium, pyrrolinium, oxazolium, triazolium, triazinium, guanidinium, uranium, sulfonium, and phosphonium, and - optionally one or more substituents attached to the charged organic core, at least one of said substituents comprising a charged moiety having a charge that is opposite in sign to, or of the same sign as, the charged moieties of the charged organic core, - the second entity is an organic, inorganic or organometallic entity, and - the net charge of the first entity is opposite in sign to the net charge of the second entity; and wherein the photoactive layer comprises a p-type semiconductor and an n-type semiconductor where the p-type semiconductor is a conjugated organic polymer or copolymer. Appeal 2019-003260 Application 14/399,009 4 The Rejections A. The Examiner rejected claims 1–4, 6, 10, 24–26, 28, and 32 under 35 U.S.C. § 103(a) as unpatentable over Pho3 and Raffaelle4 (Final Act. 10–14). B. The Examiner rejected claims 1–4, 7, 10, 24–26, 28, and 32 under 35 U.S.C. § 103(a) as being unpatentable over Pho and Jayaweera5 (Final Act. 14–17). A and B. Obviousness Because both of the obviousness rejections share similar issues as to the teachings of Pho in combination with Raffaelle or Jayaweera, we consider them together. The Examiner finds Pho teaches solar cells including two electrodes (Al/ITO), a photoactive layer (BHJ p-type/n-type semiconductor), an ETL between the photoactive layer and an electrode (Al), and a PEDOT:PSS hole transport layer (see Final Act. 10–11). The Examiner finds Pho teaches the ETL layer includes a dye which is a small molecule organic salt, including first and second ionic entities (see id.). The Examiner acknowledges that Pho does not teach the claimed organic salt or small molecule dye (Final Act. 11). The Examiner finds Raffaelle teaches “dye sensitized organic bulk heterojunction solar cells [] with two electrodes (Al/ ITO), a photoactive layer (P3HT:PCBM ; p-type:n-type semiconductor), and a PEDOT:PSS hole 3 Pho, T. V. et al., Quinacridone-Based Electron Transport Layers for Enhanced Performance in Bulk-Heterojunction Solar Cells, 21 ADV. FUNCT. MATER. 4338–4341 (2011). 4 Raffaelle, R. P. et al., Dye-sensitized bulk heterojunction polymer solar cells, 33RD IEEE PHOTOVOLTAIC SPECIALISTS CONFERENCE, 1–6 (2008). 5 Jayaweera, P. V. V. et al., Dye-sensitized near-infrared room-temperature photovoltaic photon detectors, 85 APPL. PHYS. LETT. 5754–5756 (2004). Appeal 2019-003260 Application 14/399,009 5 transport layer” (Final Act. 11). The Examiner finds Raffaelle teaches the photoactive layer includes dye 815 which “comprises a charged organic core of indolium (first entity) and iodine (second entity)” (id.). The Examiner finds that one of ordinary skill in the art would have been motivated to improve Pho’s dye sensitized solar cell (“DSSC”), “because Pho concludes that the process would be applicable generally: ‘the simple application of a solution-deposited, small molecule ETL can improve the [power conversion efficiency (‘PCE’)] of OPVs, obviating the need for post-deposition treatments such as cross-linking’” (Final Act. 12). The Examiner finds “[o]ne of ordinary skill in the art would have a reasonable expectation of success in applying the teaching of the small molecule of [Raffaelle] to Pho to because the devices share substantial structural similarities . . . and because they both utilize small molecule absorbers to enhance efficiency” (id.). The Examiner finds “Jayaweera teaches the dye sensitization of photovoltaics including solar cells using commercially available dyes such as IR 820 (anionic) - IR 1040 (cationic) (Table I)” (Final Act. 15). The Examiner finds “[o]ne of ordinary skill in the art would have a reasonable expectation of success in applying the teaching of the small molecule of Jayaweera to Pho to because the devices share substantial structural similarities such as described in Jayaweera’s Fig. 1 and because they both utilize small molecule absorbers to enhance efficiency” (Final Act. 16). The issues with respect to these rejections are: (i) Does a preponderance of evidence of record support the Examiner’s conclusion that the prior art renders the claims obvious? Appeal 2019-003260 Application 14/399,009 6 (ii) If so, have Appellants presented evidence of secondary considerations, that when weighed with the evidence of obviousness, is sufficient to support a conclusion of non-obviousness? Findings of Fact (“FF”) 1. Pho teaches the addition of an ETL between the active layer and the cathode of an OPV can facilitate electron transport to the cathode (Pho 4338). 2. Pho teaches “the use of an ETL complicates the solution processing of multilayered OPV devices, as solvents of orthogonal polarity for each successive layer are needed to prevent removal of the underlying layers, thereby necessitating the development of ETL materials that are water/alcohol-soluble” (Pho 4338). 3. Pho teaches “water/alcohol-soluble small molecules for ETLs are a simpler, more attractive alternative to their polymeric and inorganic counterparts” (Pho 4338). 4. Pho teaches: [W]ater-soluble small molecules based on the commercially available pigment quinacridone has been shown to significantly reduce the electron injection barrier in organic light emitting diodes (“OLEDs”). Given the apparent advantages in OLEDs, we evaluated the applicability of the easily accessible quinacridone material . . . as an ETL in OPVs. (Pho 4338). 5. Pho teaches a OPV structure as shown in Figure 1(c), reproduced below: Appeal 2019-003260 Application 14/399,009 7 Figure 1(c) shows a device architecture including an electrode (Al), a small molecule ETL between the electrode and a BHJ photoactive layer, a PEDOT:PSS hole transport layer, and a second electrode (ITO). (Pho 4339). 6. Pho teaches “[t]o avoid perturbation of the active layer, the quinacridone-based ETL (Na+QHSO3-) was deposited from methanol” (Pho 4339). 7. Pho teaches “[t]he addition of the ETL to the PCDTBT:PC71BM devices resulted in a significant increase in the [fill factor (‘FF’)], contributing to an overall improvement in the [power conversion efficiency (‘PCE’)] from 4.3% to 5.2%” (Pho 4339). 8. Pho teaches “[t]he use of ETL enhanced the FF of the devices and had a negligible impact on the Voc and Jsc.” (Pho 4339). 9. Pho teaches “[w]hile the use of conjugated polyelectrolyte-based ETLs has been correlated primarily to an increase in Voc we observed little- to-no change in the Voc with the addition of our small molecule Na+QHSO3− -based ETL. . . . Nonetheless, the promising improvements with the FF and PCE warrant further investigation” (Pho 4341). Appeal 2019-003260 Application 14/399,009 8 10. Pho teaches “the simple addition of a solution-deposited small molecule ETL can improve the PCE of OPVs” (Pho 4341). 11. Raffaelle teaches “[e]mpirical simulations show that molecular dyes absorbing between 800–900 nm in a properly structured device can theoretically increase the device photocurrent sufficient to reach a power conversion efficiency of 16% in a bulk heterojunction polymer solar cell” (Raffaelle 1). 12. Raffaelle teaches “[t]he incorporation of these dyes into a PCBM- P3HT device structure has shown an enhancement in the spectral response at 1.5 eV” (Raffaelle 1). 13. Raffaelle teaches “[t]he theoretical prospect of using [near-infrared (‘NIR’)] dyes to enhance the photocurrent has been calculated using [a] semi-empirical model . . . The limiting Jsc with a PCBM[70]-MEH-PPV composite is calculated to be 28.5 mA/cm2 for a 775 nm indolylidene dye and 26.8 mA/cm2 for a 815 nm indolylidene dye” (Raffaelle 3). 14. Raffaelle teaches indolium Dyes 775 and Dye 815 in Figure 8, reproduced below: Dye 775 Appeal 2019-003260 Application 14/399,009 9 Dye 815 Figure 8 shows indolium-containing small molecule dyes. (Raffaelle 4). 15. Raffaelle teaches: Empirical modeling has been performed on PCBM-Polymer bulk heterojunction using parameters from current-voltage and spectral response measurements. The maximum efficiency for these systems is calculated to be between 6 and 9%, under 1 sun illumination. The prospect of enhancing the device spectral response into the near-infrared (NIR) through the use of soluble dyes has been calculated to equal 14–17% for an optimized polymer device (Raffaelle 6). 16. Jayaweera teaches “[i]n dye-sensitization (‘DSN’), dye molecules anchored to a semiconductor surface inject carriers into a band leaving dye ions of opposite charge on the semiconductor surface. . . . These attractive features DSN have been exploited to construct solar cells using nanocrystalline films of oxide semiconductors” (Jayaweera 5754). 17. Jayaweera teaches “[t]his investigation indicates that some of these dyes sensitize the heterojunctions of the configuration, n-type semiconductor/dye/p-type semiconductor” (Jayaweera 5754). Appeal 2019-003260 Application 14/399,009 10 18. Jayaweera teaches “[t]he observation of sensitized photocurrents with IR 783, IR 820, IR 792, and IR 1040 shows that these dyes have ground and excited level positions” that energetically permit charge transfers (Jayaweera 5755). 19. The Examiner finds that IR 1040 is a cationic dye and IR 820 is an anionic dye with the following structure: IR 820 is a small molecule indolium compound forming Na+ organic salt (Final Act. 15). 20. Jayaweera teaches “[t]he peak spectral response of these devices can be readily adjusted by choice of the dye and tuning by structural modifications to the dye molecule” (Jayaweera 5756). 21. Jayaweera teaches “[e]xtensive effort is under way for improvement of the efficiencies of dye-sensitized solar cells . . . Combination of IR dyes with visible sensitizers may also enhance the efficiencies of dye-sensitized solar cells” (Jayaweera 5756). Principles of Law “The combination of familiar elements according to known methods is likely to be obvious when it does no more than yield predictable results.” KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398,416 (2007). Appeal 2019-003260 Application 14/399,009 11 Analysis We adopt the Examiner’s findings of fact and conclusions of law (see Final Act. 9–17, FFs 1–21) and agree that Pho and Raffaelle or Jayaweera render the claims obvious. We address Appellants’ arguments below. Appellants contend “Pho specifically requires the quinacridone dye- based compound as the charged material for the ETL layer and contemplates no other small molecule to replace the quinacridone dye part of the small molecule” (App. Br. 4). Appellants contend “Pho specifically teaches that the quinacridone dye is essential to its results and is the new aspect they had discovered” (id.). Appellants argue “that there would be no motivation to modify Pho to replace the quinacridone-based core material with some other small molecule core material” and therefore, “[i]t would not have been obvious to one of ordinary skill in the art to use one of the dyes in Raffaelle in place of the quinacridone dye of Pho” (App. Br. 4, 5). We find this argument unpersuasive. Pho teaches “water/alcohol- soluble small molecules for ETLs are a simpler, more attractive alternative to their polymeric and inorganic counterparts” (FF 3). Although Pho only evaluates an “easily accessible quinacridone material,” Pho does not exclude the use of other water/alcohol small molecules. Rather, Pho broadly teaches “the simple addition of a solution-deposited small molecule ETL can improve the PCE of OPVs” (FF 10). Because, “the question is whether there is something in the prior art as a whole to suggest the desirability, and thus the obviousness, of making the combination, not whether there is something in the prior art as a whole to suggest that the combination is the most desirable combination available,” we are not persuaded that the Examiner erred in modifying Pho by using known materials that were used in similar Appeal 2019-003260 Application 14/399,009 12 devices in Raffaelle and Jayaweera. In re Fulton, 391 F.3d 1195, 1200 (Fed. Cir. 2004) (citation omitted). Appellants contend: [T]he dyes taught in Raffaelle for a DSSC device are taught for use in a different context and different type of device than the quinacridone dye is used in Pho. There is no ETL layer in the Raffaelle device and the dyes are used as a sensitizer in a polymer layer, not an ETL layer and not an ETL layer based on small molecule compounds. Pho makes clear that its intention is to avoid an ETL which contains polymers . . . Thus, one of ordinary skill in the art would not be directed to the teachings of Raffaelle to modify Pho because Raffaelle is directed to a device wherein the dye is used together with and sensitizes a polymer-based layer, while Pho seeks to avoid such a polymer ETL layer. (App. Br. 5–6). Appellants’ argument is unpersuasive. “[W]hen a patent claims a structure already known in the prior art that is altered by the mere substitution of one element for another known in the field, the combination must do more than yield a predictable result.” KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 416 (2007). As shown by the Examiner, Pho discloses an organic photovoltaic device with the structure recited by the claims and suggests further investigation of small molecule organic compounds in ETLs for OPVs (FF 9). Pho is altered by the mere substitution of one known small molecule organic salt for another known in the field. Raffaelle teaches small molecule indolium dyes may be used to optimize the efficiency of PCBM- Polymer bulk heterojunction OPV devices. Although Pho and Raffaelle do not teach identical devices, “the analysis need not seek out precise teachings directed to the specific subject matter of the challenged claim, for a court can take account of the inferences and creative steps that a person of Appeal 2019-003260 Application 14/399,009 13 ordinary skill in the art would employ.” KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 418 (2007). Accordingly, we agree with the Examiner that “both devices are solar cells and the success of Raffaelle in enhancing the spectral response and PCE of the related device would reasonably suggest that the dye could be used in other devices which could be improved with a broadened spectral response such as Pho’s device” (Ans. 8). Appellants contend “[s]imilar to Raffaelle, Jayaweera teaches the use of a dye in a distinct context from how the dye in Jayaweera [Pho] is used. Thus, there is no adequate reasoning on the record to support substituting a dye taught in Jayaweera for the quinacridone dye used in Pho” (App. Br. 8). Appellants argue “[t]here is nothing to suggest that the dyes used in Jayaweera — which are used as sensitizers — would be successfully used in a device such as Pho — which is not a DSSC device and does not use the dye as a sensitizer in a polymer layer” (App. Br. 9). Appellants’ argument is unpersuasive. Although the Pho and Jayaweera devices are not identical, a person of ordinary skill in the art would have inferred that the beneficial properties of the small molecule organic salts of Jayaweera used to enhance charge transfer efficiency (FF 18) would provide similar benefits in Pho’s ETL that also requires charge transfer (FF 1). Accordingly, we agree with the Examiner that “[o]ne of ordinary skill in the art . . . would understand that sensitizing dyes demonstrated as having useful absorption properties in a related device [of Jayaweera] would likely be useful in an ETL such as taught by Pho where the known electronic properties would be compatible to improve device performance” (Ans. 14.) Appeal 2019-003260 Application 14/399,009 14 Appellants contend “the claimed devices provide significant improvement in each of fill factor, short circuit current (Jsc), open circuit voltage (Voc) and power conversion efficiency (PCE)” (App. Br. 6). Appellants’ Specification compares the “claimed devices to devices without an ETL (i.e., the same type of comparison Pho did)” (id.). Appellants contend “Pho discloses that the use of its quinacridone-based ETL layer provides a significant increase in the fill factor (FF). However, the Pho device does not provide any improvement in short circuit current (Jsc) or open circuit voltage (Voc)” (id.). We are not persuaded by Appellants’ evidence. “To be particularly probative, evidence of unexpected results must establish that there is a difference between the results obtained and those of the closest prior art, and that the difference would not have been expected by one of ordinary skill in the art at the time of the invention.” Bristol-Myers Squibb Co. v. Teva Pharms. USA, Inc., 752 F.3d 967, 977 (Fed. Cir. 2014). Appellants cite Example 2 of the Specification, incorporating the elected indolium organic salt (S1) into the ETL, as indicative of unexpected and superior results as compared to Pho’s quinacridone containing ETL. However, the combination of Pho and Raffaelle or Jayaweera teach an ETL containing an indolium compound. Moreover, the references suggest that the optimization of different organic salts will improve the performance of the OPV devices (see FFs 9–11, 15, 20). Therefore, the results are not compared to those of the closest prior art, nor would the differences have been unexpected to those of ordinary skill in the art at the time of the invention. Moreover, the results in the Specification are limited to a few compounds in specific concentrations (see Spec. 39–43, 46, 47 (Tables 1–6, Appeal 2019-003260 Application 14/399,009 15 11, 12)). The results are not commensurate in scope with claim 1, which recites numerous charged moieties without limitation to amount or concentration (see Claim 1). Unexpected results must be “commensurate in scope with the degree of protection sought by the claimed subject matter.” In re Harris, 409 F.3d 1339, 1344 (Fed. Cir. 2005). Conclusion of Law A preponderance of the evidence of record supports the Examiner’s conclusion that the prior art renders the claims obvious. Appellants have not presented evidence of secondary considerations, that when weighed with the evidence of obviousness, is sufficient to support a conclusion of non- obviousness. CONCLUSION In summary: Claim(s) Rejected Basis Affirmed Reversed 1–4, 6, 10, 24–26, 28, and 32 § 103 Pho and Raffaelle 1–4, 6, 10, 24– 26, 28, and 32 1–4, 7, 10, 24–26, 28, and 32 § 103 Pho and Jayaweera 1–4, 7, 10, 24– 26, 28, and 32 Overall Outcome 1–4, 6, 10, 24– 26, 28, and 32 No time period for taking any subsequent action in connection with this appeal may be extended under 37 C.F.R. § 1.136(a). AFFIRMED Copy with citationCopy as parenthetical citation