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 .
Summary
This is the response to the communication filed on 10/28/2025.
Claims 1 and 13-18 remain pending in the application with claims 13-18 are withdrawn from consideration.
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.
The factual inquiries 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.
Claim(s) 1 is/are rejected under 35 U.S.C. 103 as being unpatentable over Bakr et al. (US 2017/0236651) in view of Wang et al. (CN114836818 with provided machine English translation).
Addressing claim 1, Bakr discloses a method for preparing a perovskite crystal [0004], the method comprising:
a step S1 of preparing a perovskite solution containing a perovskite precursor and a first polar aprotic solvent (paragraph [0054] discloses the first reservoir includes the first solvent, such as DMF or GBR as the claimed first polar aprotic solvent) and a perovskite precursor; and
a step S2 of preparing a perovskite crystal by mixing the perovskite solution and an antisolvent as a liquid (paragraph [0061] discloses the second liquid, which is the structural equivalence to the claimed antisolvent, diffuses into the perovskite solution in the first reservoir, which corresponds to the mixing of the antisolvent and the perovskite solution; paragraph [0004 and 0061] discloses “allowing for vapor diffusion of the second liquid into the first liquid to form a modified first liquid”, which implies that the vapor of the second liquid once diffused into the first liquid becomes part of the first liquid in liquid form in order to form the modified first liquid; indeed fig. 1.1A shows the level of liquid in the inner reservoir increases as more of the liquid in the outer reservoir diffuses into the liquid of the inner reservoir, which further implies that the vapor of the second liquid transitions to liquid form as it is mixed with the first liquid in the inner reservoir, which meets the claimed limitation),
wherein the antisolvent includes a second polar aprotic solvent (paragraph [0057] discloses the second liquid is acetonitrile which is the equivalence to the claimed second polar aprotic solvent),
wherein the perovskite crystal is a single crystal
δ
-FAPbI3 (Bakr discloses the precursor in the perovskite solution includes organic cation precursor, such as formamidinium iodide [0056], and halide salt [0055], such as PbI2 [0148], which are the same as those of current application for the formation of FAPbI3; the precursors are mixed with DMF to form the same perovskite solution as that of current application; furthermore, the crystallization process occurs in a mixture of DMF, acetonitrile along with FAI and PbI2 as precursors as those of current application; therefore, Bakr discloses all of the same ingredients in the process of forming the claimed
δ
-FAPbI3 single crystal as that of current application; indeed, Ruan discloses in Experimental Section that perovskite single crystals formed by antisolvent vapor-assisted crystallization method, as described by Shi, with FAI and PbI2 as precursors leads to the formation of
δ
-FAPbI3 single crystal; therefore, the preponderance of evidence indicates that the formation process of Bakr produces the claimed single crystal
δ
-FAPbI3; Alternatively, at the time of the effective filing date of current application, one of ordinary skill in the art would have formed the claimed single crystal
δ
-FAPbI3 when forming the perovskite solution by dissolving the formamidinium iodide and PbI2 precursor materials in DMF and subsequently mixing the perovskite precursor solution with acetonitrile antisolvent as disclosed by Bakr because Bakr discloses using the same precursor materials and subjecting them to the same process using the same first DMF and second ACN solvents), and
wherein the perovskite crystal has a length of 800 to 1,500 µm and a diameter of 50 to 70 µm (Bakr discloses in paragraph [0047] that the single crystal organometallic halide, such as FAPbI3 [0046], has a length between 1 mm to 10 mm, which one end point 1 mm that falls within the claimed range of 800 to 1,500 µm, and a thickness, which corresponds to the claimed diameter, between 0.05 to 3 mm, which encompasses the claimed range of 50 to 70 µm; Bakr further discloses that the dimensions of the perovskite single crystal affect electronic defect trap-state densities, absorption band edge, charge-carrier mobility, lifetime and diffusion lengths [0069]; therefore, one would have arrived at the claimed perovskite single crystal having the claimed length and diameter when perform routine experimentation with the length and diameter of the perovskite crystals in the ranges disclosed by Bakr in order to optimize the electronic defect trap-state densities, absorption band edge, charge-carrier mobility, lifetime and diffusion lengths [0069] of the device that utilizes the perovskite crystals),
wherein the anti-solvent has a dielectric constant of 32 to 40 and wherein the antisolvent has a relative polarity of more than 0.4 and 0.6 or less based on water having a relative polarity of 1.0 (Bakr discloses acetonitrile as the antisolvent, which is the same as that of current application; therefore, the acetonitrile antisolvent of Bakr has all of the associated properties as that of current application including the claimed dielectric constant and relative polarity),
wherein the perovskite precursor comprises formamidinium (FA)I and PbI2 (Bakr discloses the precursor in the perovskite solution includes organic cation precursor, such as formamidinium iodide [0056], and halide salt [0055], such as PbI2 [0148]),
wherein the first polar aprotic solvent comprises dimethylformamide (DMF) (paragraph [0054] discloses the first reservoir includes the first solvent, such as DMF), and
wherein the antisolvent comprises acetonitrile (CH3CN) (paragraph [0057] discloses the second liquid is acetonitrile).
Bakr is silent regarding the antisolvent is in a liquid state when added to the perovskite solution.
Wang discloses a preparation method for perovskite crystallization; wherein, the method includes the step of preparing a perovskite precursor solution with DMF as the solvent (paragraph [n0008] of the translation document, which is the same solvent as that of Bakr). The method further includes the crystallization step of antisolvent diffusion method where acetonitrile as anti-solvent [n0010] is allowed to diffuse into the perovskite precursor solution, similarly to the vapor assisted crystallization step of Bakr. Alternatively, the crystallization step includes antisolvent extraction method where the antisolvent in liquid state is added to the perovskite solution [n0012].
At the time of the effective filing date of the invention, one with ordinary skill in the art would have found it obvious to modify the method of Bakr by substituting the known vapor assisted crystallization step with the known antisolvent extraction step disclosed by Wang in order to obtain the predictable result of forming perovskite crystals from the precursor solution (Rationale B, KSR decision, MPEP 2143). In the modified method of Bakr in view of Wang, the resulting perovskite crystal is
δ
-FAPbI3 because the modified method Bakr uses the same perovskite materials with the same DM as the first solution and the same acetonitrile as the antisolvent as those of current application.
With regard to the claimed perovskite crystal length and diameter, Bakr discloses in paragraph [0047] that the single crystal organometallic halide, such as FAPbI3 [0046], has a length between 1 mm to 10 mm, which one end point 1 mm that falls within the claimed range of 800 to 1,500 µm, and a thickness, which corresponds to the claimed diameter, between 0.05 to 3 mm, which encompasses the claimed range of 50 to 70 µm; Bakr further discloses that the dimensions of the perovskite single crystal affect electronic defect trap-state densities, absorption band edge, charge-carrier mobility, lifetime and diffusion lengths [0069]; therefore, one would have arrived at the claimed perovskite single crystal having the claimed length and diameter when perform routine experimentation with the length and diameter of the perovskite crystals in the ranges disclosed by Bakr in order to optimize the electronic defect trap-state densities, absorption band edge, charge-carrier mobility, lifetime and diffusion lengths [0069] of the device that utilizes the perovskite crystals.
Response to Arguments
Applicant's arguments filed 10/28/2025 regarding the 35 USC 103 rejection of claim 1 have been fully considered but they are not persuasive for the following reasons:
Firstly, the Applicants argued that Bakr and Wang differ significantly in their crystallization methods, perovskite precursor types and the desired perovskite crystal composition. The argument is acknowledged; however, it is not persuasive because it does not address the content of the rejection. The rejection does not call for modifying the method of Bakr with the crystallization method, the perovskite precursor types and the desired perovskite crystal composition of Wang. The modification simply calls for replacing the introduction of acetonitrile to the perovskite solution containing the perovskite precursor and the dimethylformamide as vapor with introducing acetonitrile to the perovskite solution as liquid. It is noted that replacing the introduction of acetonitrile as vapor with the introduction of acetonitrile as liquid would not change the resulting solution in step S2 for crystallization because the added acetonitrile is mixed in the perovskite solution of step S1 as a liquid. This is evidenced by the disclosure of Bakr in paragraph [0061] that states the second liquid, which is the structural equivalence to the claimed antisolvent, diffuses into the perovskite solution in the first reservoir, which corresponds to the mixing of the antisolvent and the perovskite solution; paragraph [0004 and 0061] discloses “allowing for vapor diffusion of the second liquid into the first liquid to form a modified first liquid”, which implies that the vapor of the second liquid once diffused into the first liquid becomes part of the first liquid in liquid form in order to form the modified first liquid; indeed fig. 1.1A shows the level of liquid in the inner reservoir increases as more of the liquid in the outer reservoir diffuses into the liquid of the inner reservoir, which further implies that the vapor of the second liquid transitions to liquid form as it is mixed with the first liquid in the inner reservoir. Wang discloses crystallization is carried out with either anti-solvent diffusion method, which is similar to that of Bakr, or anti-solvent extraction method where the anti-solvent is added as a liquid (paragraph [n0012]). In other words, the anti-solvent diffusion method and the anti-solvent extraction method would lead to the same result of forming crystals from the perovskite solution. Therefore, the preponderance of evidence indicates that substituting the known anti-solvent diffusion method of Bakr with the known anti-solvent extraction method of Wang would lead to the formation of the single crystal
δ
-FAPbI3 as claimed because the modified method of Bakr in view of Wang use the same DMF first polar aprotic solvent, the same FAI and PbI2 perovskite precursors and the same acetonitrile antisolvent, which exists in liquid form after being added to the perovskite solution.
The Applicants further argued since Bakr essentially discloses a vapor-assisted crystallization method to prepare a single-crystal organometal halide perovskite, there is no evidence to show it would have been obvious for one of skill in the art to modify the vapor-assisted crystallization method of Bakr with the method of Wang. The argument is not persuasive because Wang clearly provides evidence that either anti-solvent diffusion i.e. vapor-assisted crystallization or anti-solvent extraction method, i.e. adding the acetonitrile anti-solvent as liquid, would lead to the same formation of crystal. Therefore, the preponderance of evidence provided by Wang indicates that substituting the known anti-solvent diffusion method of Bakr with the known anti-solvent extraction method of Wang would lead to the formation of the single crystal
δ
-FAPbI3 as claimed because the modified method of Bakr in view of Wang use the same DMF first polar aprotic solvent, the same FAI and PbI2 perovskite precursors and the same acetonitrile antisolvent, which exists in liquid form after being added to the perovskite solution.
The Applicants further argued that it is not obvious for one of skill in the art to select DMF as a solvent for dissolving a perovskite precursor amount the various listed solvents or selecting acetonitrile as an antisolvent at the same time in view of Bakr and/or Wang. The argument is not persuasive because Bakr discloses three possible choices for the first solution, which are DMF, DMSO and GBR, with DMF [0053] being recited in multiple examples as the first solution. Likewise, Bakr discloses four possible choices for the anti-solvent, which are dichloromethane, chloroform, acetonitrile and toluene [0057]. Therefore, it would be well within the technical grasp of one of ordinary skill in the art to select DMF as the first polar aprotic solvent and acetonitrile as the antisolvent in the limited choices provided by Bakr for the preparation of perovskite crystal method.
For the reasons above, Examiner maintains the position that claim 1 is obvious over the disclosure of Bakr in view of Wang because the modified method of Bakr in view of Wang use the same DMF first polar aprotic solvent, the same FAI and PbI2 perovskite precursors and the same acetonitrile antisolvent, which exists in liquid form after being added to the perovskite solution.
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 BACH T DINH whose telephone number is (571)270-5118. The examiner can normally be reached Mon-Friday 8:00 - 4:30 EST.
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/BACH T DINH/Primary Examiner, Art Unit 1726 11/13/2025
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