DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Drawings
The drawings were received on August 5, 2026. These drawings are acceptable.
Response to Amendment
The amendments filed on August 5, 2026 have been entered. Claims 1, 3, 5, 9-18 and 20-22 are now pending. The amendments entered to the presented claims have overcome the prior objections, 112(b) rejections, 102 rejections and 103 rejections in the Non-Final Office Action dated May 5, 2026. The amendments to the specification and drawings have overcome the prior objcetions.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 5 and 20 rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 5, dependent on claim 1, recites a limitation whereby heat is applied to the precipitate from claim 1. However, it is unclear at which step whereby heat is applied to the precipitate from claim 1. The heat could be applied while obtaining the precipitate from the volume of water, during the drying step, or when placing the precipitate in an organic solvent. Thus, claim 5 is indefinite. For the purposes of examination, the heating step will be interpreted as applied during drying.
Claim 20, dependent on claim 18, recites a limitation whereby heat is applied to “the volume of water” from claim 18. Claim 18 recites adding halide precursors to a volume of water and also obtaining a precipitate from the volume of water. Thus, it is unclear in claim 20 at which step should heat be applied to the volume of water whether to the precursor solution or to the volume of water for obtaining the precipitate. Therefore, claim 20 is indefinite. For the purposes of examination, the heating step will be interpreted as applied during the adding of precursors to the volume of water.
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, 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.
Claims 1, 3, and 18 are rejected under 35 U.S.C. 103 as being unpatentable over Hu et al (NPL: "Rapid synthesis of cesium lead halide perovskite nanocrystals...") in view of Liu et al (CN112683963A).
Regarding claim 1, Hu discloses synthesis of CsPbBr3 (cesium-lead-halide) nanocrystals by adding CsBr (cesium bromide, a cesium halide) and PbBr2 (lead halide) to a volume of water. Furthermore, Hu discloses that the water containing the precursors is applied to a glass slide and air-dried naturally, leaving behind a white precipitate which are photoluminescent nanocrystals. Hu does not place the precipitate into an organic solvent after synthesis. Liu does teach dispersion of cesium-lead-halide precipitate into hexane, an organic solvent, in steps 3 and 4 of their process. There is no other organic solvent with hexane, thus the organic solvent is free of “octadecene, dimethyl formamide, and dimethyl sulfoxide”. Liu disperses the precipitate into an organic solvent to obtain long-term stable colloidal CsPbBr3 quantum dot solution and allows for use in further applications or modifications. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to disperse the cesium-lead-halide precipitate into a pure hexane solution to obtain a long-term stable colloidal solution. In examples 1-3, Liu takes 0.086, 0.043, or 0.129mL of 10mmol/L CsPbBr3 (corresponds to 0.499, 0.2495, or 0.7485 mg) and places into 3mL of hexane which falls within claimed range. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to disperse the precipitate of Hu, into hexane, at the concentrations informed by Liu as a known suitable concentration for long-term dispersion of cesium-lead halide nanocrystals and arrive at the invention as claimed. Thus, Hu and Liu teach the claimed “A method for preparing a cesium-lead-halide nanocrystal, comprising: adding a cesium halide and a lead halide to a volume of water, wherein the cesium halide is selected from the group consisting of cesium bromide, cesium iodide, and cesium chloride; obtaining a precipitate from the volume of water and drying the precipitate; and placing the precipitate in an organic solvent, wherein: the organic solvent is selected from toluene, chlorobenzene, and hexane, the organic solvent is free of octadecene, dimethyl formamide, and dimethyl sulfoxide, and the precipitate is provided at from about 0.02 mg to 1 mg per 3 to 15 mL of organic solvent.”.
Regarding claim 3, Hu and Liu teach the method of claim 1. Hu discloses use of 0.2 mmol of CsBr and 0.2 mmol PbBr2 in the volume of water (equimolar amounts of precursors). Therefore, Hu and Liu teach the claimed “The method of claim 1, wherein the cesium halide and lead halide have the same molarity in the volume of water”.
Regarding claim 18, Hu teaches synthesis of CsPbBr3 (cesium-lead-halide) powder by adding CsBr (cesium bromide) and PbBr2 (lead halide) to a volume of water where the final product is a precipitated white powder. Furthermore, Hu discloses that the water containing the precursors is applied to a glass slide and air-dried naturally, leaving behind a white precipitate which are photoluminescent nanocrystals. Hu does not place the precipitate into an organic solvent after synthesis. Liu does teach dispersion of cesium-lead-halide precipitate into hexane, an organic solvent, in steps 3 and 4 of their process. There is no other organic solvent with hexane, thus the organic solvent is free of “octadecene, dimethyl formamide, and dimethyl sulfoxide”. Liu disperses the precipitate into an organic solvent to obtain long-term stable colloidal CsPbBr3 quantum dot solution and allows for use in further applications or modifications. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to disperse the cesium-lead-halide precipitate into a pure hexane solution to obtain a long-term stable colloidal solution. In examples 1-3, Liu takes 0.086, 0.043, or 0.129mL of 10mmol/L CsPbBr3 (corresponds to 0.499, 0.2495, or 0.7485 mg) and places into 3mL of hexane which falls within claimed range. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to disperse the precipitate of Hu, into hexane, at the concentrations informed by Liu as a known suitable concentration for long-term dispersion of cesium-lead halide nanocrystals and arrive at the invention as claimed. Thus, Hu and Liu teach the claimed “A method of preparing a cesium-lead-halide powder, comprising: adding a cesium halide and a lead halide to a volume of water, wherein the cesium halide is selected from the group consisting of cesium bromide, cesium iodide, and cesium chloride; obtaining a precipitate from the volume of water and drying the precipitate; and placing the precipitate in an organic solvent, wherein: the organic solvent is selected from toluene, chlorobenzene, and hexane, the organic solvent is free of octadecene, dimethyl formamide, and dimethyl sulfoxide, and the precipitate is provided at from about 0.02 mg to 1 mg per 3 to 15 mL of organic solvent”.
Claims 5 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Hu et al (NPL: "Rapid synthesis of cesium lead halide perovskite nanocrystals...") in view of Liu et al (CN112683963A) as applied to claims 1 and 18 above, and further in view of Peng et al (CN111994947A).
Regarding claim 5, Hu and Liu teach the method of claim 1. Hu does not teach a heating step but allows the precipitate to air dry naturally on a glass substrate for an undisclosed period of time. Peng also teaches preparation of cesium lead halides and dries the obtained solid material (CsPbBr3) at 70°C for an undisclosed period of time. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to heat at 70°C until the precipitate is fully dried or dried to an allowable extent which would likely arrive at a time in the claimed range. Therefore, Hu, Liu, and Peng teach the claimed “The method of claim 1, further comprising applying heat to the precipitate at a temperature of from about 40 to 90°C for a period of time of from about 30 minutes to about 400 minutes”
Regarding claim 20, Hu and Liu teach the method of claim 18. Hu does not teach a heating step for the volume of water containing precursors. Peng also teaches preparation of cesium lead halide powders by mixing precursors into a volume of water. Peng describes injecting the cesium bromide aqueous solution heated at 70°C into the lead bromide solution (also heated at 70°C) and stirring for more than 30 minutes. Peng discloses the stirring occurs at 25-80°C. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to select for a temperature within the overlapping range, such as maintaining at the 70°C used in prior steps, and stirring for at least 30 minutes within the overlapping time range, as a known heating and mixing step in preparing cesium lead halide powders and arrive a the invention as claimed. Thus, Hu, Liu, and Peng teach the claimed “The method of claim 18, further comprising applying heat to the volume of water at a temperature of from about 40 to 90°C for a period of time of from about 30 minutes to about 400 minutes”
Claims 9 and 10 are rejected under 35 U.S.C. 103 as being unpatentable over Hu et al (NPL: "Rapid synthesis of cesium lead halide perovskite nanocrystals...") in view of Liu et al (CN112683963A) as applied to claim 1 above, and further in view of De Roo et al (NPL: "Highly Dynamic Ligand Binding...").
Regarding claim 9, Hu and Liu teach the method of claim 1 but do not disclose addition of oleic acid into the organic solvent (hexane of Liu). De Roo also teaches synthesis of CsPbBr3 nanocrystals and further teaches post-synthesis modification for improving purity and maintaining optical, colloidal and material integrity. After precipitating the nanocrystals from solution, De Roo collects them via centrifugation and redissolves them in hexane. De Roo adds a small excess of oleic acid and oleylamine and redisperses again in hexane. The oleic acid and oleylamine improve purity and maintain optical, colloidal, and material integrity. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to add oleic acid to the hexane dispersion in order to improve purity and maintain optical, colloidal, and material integrity of the nanocrystals. Thus, Hu, Liu, and De Roo teach the claimed “The method of claim 1, wherein the organic solvent further comprises oleic acid (OA)”.
Regarding claim 10, Hu and Liu teach the method of claim 1 but do not disclose addition of oleylamine into the organic solvent (hexane of Liu). De Roo also teaches synthesis of CsPbBr3 nanocrystals and further teaches post-synthesis modification for improving purity and maintaining optical, colloidal and material integrity. After precipitating the nanocrystals from solution, De Roo collects them via centrifugation and redissolves them in hexane. De Roo adds a small excess of oleic acid and oleylamine and redisperses again in hexane. The oleic acid and oleylamine improve purity and maintain optical, colloidal, and material integrity. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to add oleylamine to the hexane dispersion in order to improve purity and maintain optical, colloidal, and material integrity of the nanocrystals. Thus, Hu, Liu, and De Roo teach the claimed “The method of claim 1, wherein the organic solvent further comprises oleylamine (OAm)”
Claims 11-14 are rejected under 35 U.S.C. 103 as being unpatentable over Hu et al (NPL: "Rapid synthesis of cesium lead halide perovskite nanocrystals...") in view of Liu et al (CN112683963A) as applied to claim 1 above, and further in view of Marín et al (NPL: "Ultrasonic dispersion of nanostructured materials...").
Regarding claim 11, Hu and Liu teach the method of claim 1 but do not teach a sonication step. Marín does teach ultrasonication as a technique to disperse synthesized pyrogenic precipitated nanomaterials (results section), which can be broadly applied to nanomaterials or nanoparticles as disclosed in the introduction. Marín utilizes ultrasonication to disintegrate submicron aggregates, fragment or erode agglomerates/aggregates, and achieve a maximum dispersion into smallest dispersible units. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to ultrasonicate the precipitate in an organic solvent to disperse the precipitates into smaller units and break up agglomerations. Therefore, Hu, Liu, and Marín teach the claimed “The method of claim 1, wherein the method further comprises ultrasonication”.
Regarding claim 12, Hu, Liu and Marín teach the method of claim 11. Marín, however, directly sonicates the precipitate in the solution. Although Marín applies the probe into the solution containing the precipitate, Marín discloses that ultrasonication may occur in a water bath to avoid introduction of contamination from the probe into the sample (final paragraph of section 3.2.3 and first paragraph of 3.1). Ultrasonication via water bath achieves the same result of dispersing the nanoparticles as water serves as the medium for transferring sound energy to a container that holds the sample. Therefore, it would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to apply ultrasonication to a water bath in order to avoid introduction of contaminants from the sonicator probe. Together, Hu, Liu, and Marín teach the claimed “The method of claim 11, wherein ultrasonication is provided to a water bath containing the organic solvent”.
Regarding claim 13, Hu, Liu and Marín teach the method of claim 11. Further, in Fig.1, Marín correlates the caloric energy density (heat production of ultrasonication) with the dynamic light scattering of the sonicated particles. From the heat production of ultrasonication, the dispersion time can be calculated from equations 1 and 2 of Marín. In Fig. 1, Marín discloses sonication times of 23 min to 128 min (final paragraph of section 3.1) which has overlap with the claimed range of “about 30 minutes to about 400 minutes”. There is a steady decrease of the average particle size with ongoing dispersion. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to ultrasonicate the sample for a time within the overlapping range and arrive at the claimed limitation to produce nanoparticles with a smaller average particle size. Therefore, Hu, Liu, and Marín teach the claimed “The method of claim 11, wherein ultrasonication is provided for a period of from about 30 minutes to about 400 minutes”.
Regarding claim 14, Hu, Liu and Marín teach the method of claim 11. Further, Marín teaches in the first sentence of the third paragraph of section 3.1 that typical ultrasonic dispersion equipment is operated at frequencies in the range of 20 kiloHertz (kHz) to 100kHz. This range overlaps with the claimed range of 20kiloHertz to about 10megaHertz. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to select a frequency in the overlapping range and arrive at the claimed limitation. Therefore, Hu, Liu and Marín teach the claimed “The method of claim 11, wherein ultrasonication is provided at a frequency of from about 20 kiloHertz to about 10 megaHertz”
Claims 15, 16, and 21 are rejected under 35 U.S.C. 103 as being unpatentable over Hu et al (NPL: "Rapid synthesis of cesium lead halide perovskite nanocrystals...") in view of Liu et al (CN112683963A) as applied to claims 1 and 18 above, and further in view of Wang et al (CN112500857A).
Regarding claim 15, Hu and Liu teach the method of claim 1 but do not disclose use of a dopant. Wang teaches doping of cesium halide nanocrystal in a volume of water solution with a metal halide (MX structure, where M can be divalent cation or trivalent such as Al3+). Wang teaches that use of a dopant improves crystal lattice stability, increases ion binding energy, and can modify emission spectra. Though Wang does not teach providing the metal halide in the original precursor solution, Hu et al teaches a one-step synthesis method. Therefore, it would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to add a metal halide precursor in the volume of water to dope the cesium-lead halide nanocrystal with a predictable outcome of improving crystal lattice stability, increasing ion binding energy, or modifying emission spectra. Thus, Hu, Liu, and Wang teach the claimed “The method of claim 1, wherein the volume of water further comprises a metal halide to dope the cesium-lead halide nanocrystal”.
Regarding claim 16, Hu, Liu, and Wang teach the method of claim 15. Wang teaches in examples the case of zinc bromide, nickel chloride, or sodium chloride as the dopant. However, Wang broadly discloses the dopant precursor can be a metal halide (chloride, bromide, or iodide) where the metal can be divalent or trivalent specifically mentioning Al3+. Wang suggests that use of hetero-valent cation doping increases ion binding energy, improves the stability of the crystal lattice, and can blue shift the spectrum. Therefore, it would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to choose aluminum bromide, chloride, or iodide from the list provided by Wang as the dopant to increase ion binding energy, improve the stability of the crystal lattice, and/or shift the emission spectrum. Thus, Hu, Liu and Wang exemplify the claimed “The method of claim 15, wherein the metal halide is selected from the group consisting of aluminum bromide, aluminum chloride, and aluminum iodide”.
Regarding claim 21, Hu and Liu teach the method of claim 18 but do not disclose use of a dopant. Wang teaches doping of cesium halide nanocrystal in a volume of water solution with a metal halide (MX structure, where M can be divalent cation or trivalent such as Al3+). Wang teaches that use of a dopant improves crystal lattice stability, increases ion binding energy, and can modify emission spectra. Though Wang does not teach providing the metal halide in the original precursor solution, Hu et al teaches a one-step synthesis method. Therefore, it would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to add a metal halide precursor in the volume of water to dope the cesium-lead halide nanocrystal with a predictable outcome of improving crystal lattice stability, increasing ion binding energy, or modifying emission spectra. Thus, Hu, Liu, and Wang teach the claimed “The method of claim 18, wherein the volume of water further comprises a metal halide to dope the cesium-lead halide nanocrystal”
Claims 17 and 22 are rejected under 35 U.S.C. 103 as being unpatentable over Hu et al (NPL: "Rapid synthesis of cesium lead halide perovskite nanocrystals...") in view of Liu et al (CN112683963A) as applied to claims 1 and 18 above, and further in view of Zhen Li et al (NPL: “Stabilizing Perovskite Structures by Tuning...").
Regarding claim 17, Hu and Liu teach the method of claim 1 but do not mention a partial substitution of cesium halide for methylammonium (MA) or formamidinium (FA). Li et al do teach a partial substitution of cesium halide for FA. In the SI methods, an FA precursor is added in solution with lead and Cs halide precursors where the resulting hybrid inorganic-organic halide perovskite has a composition of Cs partially substituted with FA. Li discloses that hybrid inorganic-organic halide perovskites have drawn tremendous interest in photovoltaic community because of excellent optoelectronic properties and solution-processable features. Li shows that alloyed material displays more stable α-phase, leading to better stability in active layer and in PV device. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to partially substitute the cesium halide with FA in the precursor solution to improve stability of the composition. Therefore, Hu, Liu, and Li teach the claimed “The method of claim 1, wherein the cesium halide is at least partially substituted with methylammonium or formamidinium”.
Regarding claim 22, Hu and Liu teach the method of claim 18 but do not mention a partial substitution of cesium halide for methylammonium (MA) or formamidinium (FA). Li et al do teach a partial substitution of cesium halide for FA. In the SI methods, an FA precursor is added in solution with lead and Cs halide precursors where the resulting hybrid inorganic-organic halide perovskite has a composition of Cs partially substituted with FA. Li discloses that hybrid inorganic-organic halide perovskites have drawn tremendous interest in photovoltaic community because of excellent optoelectronic properties and solution-processable features. Li shows that alloyed material displays more stable α-phase, leading to better stability in active layer and in PV device. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to partially substitute the cesium halide with FA in the precursor solution to improve stability of the composition. Therefore, Hu, Liu, and Li teach the claimed “The method of claim 18, wherein the cesium halide is at least partially substituted with methylammonium or formamidinium”.
Response to Arguments
Applicant's arguments filed August 5, 2026 have been fully considered but they are not persuasive. The applicant argues with incorporation of claims 6-8 into independent claim 1 along with a further limitation that "the organic solvent is free of octadecene, dimethyl formamide, and dimethyl sulfoxide" and amendments to independent claim 18 (with the same further limitation) distinguish the invention from Hu in view of Xu and Hu in view of Liu. The applicant argues that Hu dissuades against usage of solvents in general while each of Xu and/or Liu expressly include one or more of the toxic solvents (ODE, dimethyl formamide, and/or dimethyl sulfoxide).
Hu teaches a solvent-free synthesis process for CsPbBr3 nanocrystals. However, claims 1 and 18 as currently presented, only require use of an organic solvent after obtaining a precipitate which can be a powder and/or nanocrystal for cesium-lead halides. Hu only teaches away from inclusion of solvents in the synthesis process and does not specifically teach away from use of solvents afterwards in post-synthesis step. Thus, the inclusion of an organic solvent, as informed by either Xu or Liu, post-synthesis of Hu’s cesium-lead halides would be a reasonable modification since the solvent is not included as a synthesis step. Additionally, while Liu include a “toxic solvent” in their synthesis procedure, the claims as currently presented expressly include an organic solvent, and exclude the claimed toxic organic solvents, only during the placing step after the precipitate is obtained and dried. Liu places its obtained precipitate in an organic solvent, hexane, which is free of the claimed toxic solvents after the synthesis of precipitate as well. Thus, the combined teachings of Hu in view of Liu render the independent claims 1 and 18 obvious.
The arguments filed August 5, 2026 to claims 1 and 18 in response to the 102 rejections are moot because the amendments have overcome the prior rejection.
Conclusion
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). Applicant is reminded of the extension of time policy as set forth in 37 CFR 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 nonprovisional extension fee (37 CFR 1.17(a)) 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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Noa W. F. Grooms whose telephone number is (571)272-9981. The examiner can normally be reached M-F 7:30-3:30PM EST.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Curtis Mayes can be reached at (571) 272-1234. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC)
at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/NWFG/Examiner, Art Unit 1759
/MELVIN C. MAYES/Supervisory Patent Examiner, Art Unit 1759
