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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on April 29, 2026, has been entered.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claim 1 and 5-8 is/are rejected under 35 U.S.C. 103 as being unpatentable over a publication to Khoram, et al. entitled “Growth and characterization of PDMS-stamped halide perovskite single microcrystals,” Journal of Physical Chemistry, Vol. 120, pp. 6475-81 (2018) (hereinafter “Khoram”) in view of U.S. Patent Appl. Publ. No. 2021/0367150 to Feng, et al. (“Feng”).
Regarding claim 1, Khoram teaches a method of preparing a single crystal perovskite (see the Abstract, Figs. 1-3, and entire reference which teach a method of preparing single crystals of a perovskite), comprising:
applying a perovskite precursor solution onto a substrate (see Fig. 1 and the Experimental Methods section at p. 6476 which teach preparing a halide perovskite solution by mixing PBr2 with CH3NH3Br in dimethylformamide (DMF) or dimethyl sulfoxide (DMSO) and spin-coating the solution onto a fused silica substrate);
covering the perovskite precursor solution with a polymer cover (see Fig. 1 and the Experimental Methods section at p. 6476 which teach that the wet substrate was pressed face down onto a piece of PDMS); and
heat treating the perovskite precursor solution to grow the single crystal perovskite (see Fig. 1 and the Experimental Methods section at p. 6476 which teach heating on a hot plate at 100 °C or 150 °C for 2-5 min until single crystals of CH3NH3PbBr3 formed).
Khoram does not teach that the substrate is a flexible substrate which is polyimide (PI). However, in Figs. 1-4 and ¶¶[0032]-[0056] as well as elsewhere throughout the entire reference Feng teaches an analogous method of fabricating a perovskite thin film on a substrate as part of a process for forming a transparent display. In Fig. 2 and ¶[0039] Feng specifically teaches that in step (S4) the precursor solution is coated on an upper surface of a substrate by spin-coating to form a perovskite layer and that the substrate may be a flexible organic substrate and, in one embodiment, may be a polyimide (PI) substrate. In Fig. 4 and ¶¶[0053]-[0054] Feng further teaches that the perovskite film (2) is formed directly on the substrate (1) as part of a process of forming a display device. Thus, a PHOSITA prior to the effective filing date of the invention would look to the teachings of Feng and would recognize that a flexible material such as polyimide may be used as the substrate in the method of Khoram with the motivation for doing so being to produce flexible electronic devices. The combination of prior art elements according to known methods to yield predictable results has been held to support a prima facie determination of obviousness. All the claimed elements are known in the prior art and one skilled in the art could combine the elements as claimed by known methods with no change in their respective functions, with the combination yielding nothing more than predictable results to one of ordinary skill in the art. KSR International Co. v. Teleflex Inc., 550 U.S. 398, __, 82 USPQ2d 1385, 1395 (2007). See also, MPEP 2143(A).
Regarding claim 5, Khoram teaches that the polymer cover includes at least one selected from the group consisting of polyimide (PI), polydimethylsiloxane (PDMS), polytetrafluoroethylene (PTFE), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), and polyvinylidene-chloride (PVDC) (see Fig. 1 and the Experimental Methods section at p. 6476 which teach that the wet substrate was pressed face down onto a piece of PDMS which functions as the polymer cover).
Regarding claim 6, Khorma teaches applying a pressure to the polymer cover before the heat treating (see Fig. 1 and the Experimental Methods section at p. 6476 which teach that the wet substrate was pressed face down onto a piece of PDMS which necessarily applies pressure to the PDMS; moreover, the application of pressure necessarily occurs before the perovskite solution is heated to the growth temperature of 100 or 150 °C).
Regarding claim 7, Khoram teaches that the heat treating is performed in a temperature range of 60°C to 100°C (see Fig. 1 and the Experimental Methods section at p. 6476 which teach heating on a hot plate at 100 °C for 2-5 min until single crystals of CH3NH3PbBr3 formed).
Regarding claim 8, Khoram teaches that the heat treating is performed in a pressure range of 0.5 bar to 1 bar (See Fig. 1 and the Experimental Methods section at p. 6476 which teach heating on a hot plate at 100 °C for 2-5 min until single crystals of CH3NH3PbBr3 formed. A person of ordinary skill in the art prior to the effective filing date of the invention would recognize that this was performed at atmospheric pressure or 760 Torr which is sufficiently close to the claimed upper limit of 1 bar (750 Torr) that it would be reasonably expected to yield the same result. A prima facie case of obviousness exists where the claimed ranges and prior art ranges do not overlap but are close enough that one skilled in the art would have expected them to have the same properties. Titanium Metals Corp. of America v. Banner, 778 F.2d 775, 227 USPQ 773 (Fed. Cir. 1985). See also MPEP 2144.05(I). Alternatively, since the pressure during crystal growth influences crystal formation, including the solvent evaporation rate, it is considered to be a result-effective variable, i.e., a variable which achieves a recognized result. See, e.g., In re Antonie, 559 F.2d 618, 195 USPQ 6 (CCPA 1977). See also MPEP 2144.05(II)(B). It therefore would have been within the capabilities of a person of ordinary skill in the art to utilize routine experimentation to determine the optimal pressure, including within the claimed range of 0.5 to 1 bar, necessary to produce perovskite single crystals in the method of Khoram and Feng which possess the desired materials properties.).
Claims 3-4 is/are rejected under 35 U.S.C. 103 as being unpatentable over Khoram in view of Feng and further in view of U.S. Patent Appl. Publ. No. 2021/0062364 to Joglekar, et al. (“Joglekar”).
Regarding claim 3, Khoram and Feng do not teach that the flexible substrate includes a spacer formed on the flexible substrate. However, in Figs. 2-3 and ¶¶[0113]-[0127] as well as elsewhere throughout the entire reference Joglekar teaches an analogous system and method for the growth of perovskite single crystal from a solution. In Figs. 2A & 3A-C and ¶¶[0117]-[0119] Joglekar specifically teaches the use of a spacer formed from sidewalls comprised of a polymeric material such as polydimethylsiloxane (PDMS) to contain the precursor solution within a predefined area with a defined thickness. Thus, a person of ordinary skill in the art prior to the effective filing date of the invention would look to the teachings of Joglekar and would be motivated to incorporate one or more spacers manufactured from a polymeric material such as PDMS in the method of Khoram and Feng in order to precisely define the area and thickness where crystallization of the perovskite solution occurs.
Regarding claim 4, Khoram and Feng do not teach that the spacer includes at least one selected from the group consisting of polyimide (PI), polydimethylsiloxane (PDMS), polytetrafluoroethylene (PTFE), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), and polyvinylidene-chloride (PVDC). However, as noted supra with respect to the rejection of claim 3, in Figs. 2A & 3A-C and ¶¶[0117]-[0119] Joglekar specifically teaches the use of a spacer formed from sidewalls comprised of a polymeric material such as polydimethylsiloxane (PDMS) to contain the precursor solution within a predefined area with a defined thickness. Thus, a person of ordinary skill in the art prior to the effective filing date of the invention would look to the teachings of Joglekar and would be motivated to incorporate one or more spacers manufactured from a polymeric material such as PDMS in the method of Khoram and Feng in order to precisely define the area and thickness where crystallization of the perovskite solution occurs.
Response to Arguments
Applicants’ arguments filed April 29, 2026, have been fully considered, but they are moot in view of the new grounds of rejection set forth in this Office Action which were necessitated by applicants’ claim amendments. Applicants’ argument that Chen does not teach or suggest the use of a polyimide substrate (see applicants’ 4/29/2026, reply, pp. 11-13) is moot in view of the introduction of U.S. Patent Appl. Publ. No. 2021/0367150 to Feng, et al. to teach the use of a polyimide substrate.
Conclusion
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/KENNETH A BRATLAND JR/Primary Examiner, Art Unit 1714
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