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 .
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
Election/Restrictions
Applicant’s election of Group I, claims 1-10 and 20-24 in the reply filed on 12 December 2025 is acknowledged. Because applicant did not distinctly and specifically point out the supposed errors in the restriction requirement, the election has been treated as an election without traverse (MPEP § 818.01(a)).
Claims 11-19 and 25-30 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 12 December 2025.
Claim Objections
Claims 1 is objected to because of the following informalities:
Claim 1 should be amended to read: “…comprising [[the]] a 4H structure…”
Appropriate correction is required.
Information Disclosure Statements
The Information Disclosure Statements filed on 19 December 2025 and 23 May 2023 have been received and considered by the Examiner.
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 2-4 and 6-10 are 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.
Claims 2, 3, 4, 7, 8, and 10 each recite "the microcrystalline 4H silicon phase,” “the 4H-Si”, “the material,” “the 4H-Si material,” or “the 4H-Si phase.” Each of these limitations lack sufficient antecedent basis. For the purposes of further examination, they all are interpreted as referring to the “4H-Si crystalline allotrope of silicon” recited in claim 1. It is suggested that upon amendment consistent language be used to refer to the composition of claim 1 wherever it is referenced in the dependent claims. Claim 9 depends upon claim and is likewise rejected.
Claim 3 further recites the limitation of “unambiguous Raman spectra and X-ray diffraction patterns.” However, it is unclear what specific characteristics would be required to make the spectra and diffraction patterns unambiguous and therefore the claim is indefinite.
Claim 6 is rejected because it is unclear whether the claim requires the heating of Na4Si24 in the presence of iodine, or if it requires that the structural conversion to 4H-Si occur both (1) in the presence of iodine and an unspecified Si source, and (2) that the conversion separately occurs when heating Na4Si24 at temperatures between 300-800 °C.
Claim 10 recites the limitation of “desirable elastic properties.” However, it is unclear what specific characteristics would be required to make the elastic properties desirable and the claim is indefinite.
Additionally, the term “significant differences” in claim 10 is a relative term which renders the claim indefinite. The term “significant differences” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. It is therefore indefinite what differences in the conduction band minima are required to meet the limitations of the claim.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claims 1-10 and 20-24 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Shiell et al. (Physical Review Letters 126, 215701 (2021); NPL Document BL on the IDS filed 19 December 2025; references below are made to the Applicant-provided pre-print). It is noted that the Shiell reference lists authors that are not inventors on the present application.
Regarding claim 1, Shiell discloses a 4H-Si crystalline allotrope of silicon comprising the 4H structure with highly oriented microcrystals (abstract, p. 1; p. 3 describes the product as exhibiting micro-crystallinity).
Regarding claim 2, Shiell discloses the material of claim 1, and further describes the material as “bulk crystalline 4H” (abstract), which is interpreted as containing no disordered material. It is further noted that the method of preparation is identical to that presently disclosed and so the materials are expected to have the same crystalline characteristics.
Regarding claim 3, Shiell discloses the material of claim 1, and further discloses that the material exhibits unambiguous Raman spectra (show all Raman-active phonon modes allowing clear disambiguation of the 4H hexagonal stacking sequence; p. 4, ¶ 1) and X-ray diffraction patterns (XRD pattern is not consistent with other possible hexagonal stacking sequences; p. 3, ¶ 1).
Regarding claim 4, Shiell discloses the material of claim 1, and further discloses that the material exhibits the characteristics of an indirect band gap semiconductor with a band gap near 1.2 eV (4H-Si is a semiconductor with an indirect band gap of ~1.2 eV; p. 5, ¶ 2).
Regarding claim 5, Shiell discloses the material of claim 1, and further discloses that the 4H-Si is produced by heating Si24 at 9 GPa and a temperature of 780°C (p. 10, ¶ 1) and that structural conversion to 4H-Si is dependent on temperature and heating duration (p. 2, ¶ 4).
Regarding claim 6, Shiell discloses the material of claim 1. The further limitations of claim 6 merely describe an inherent property of the materials disclosed: that they are able to convert to 4H-Si in the presence of iodine and when heating Na4Si24 at temperatures between 300-800 °C. Even if the claim is interpreted requiring that the material of claim 1 be prepared by this (or these) method, the patentability of a product does not depend on its method of production. In re Thorpe, 777 F.2d 695, 698, 227 USPQ 964, 966 (Fed. Cir. 1985). MPEP 2113(I). Given that the specification states that conversion to 4H-Si also occurs in the presence of iodine and when heating Na4Si24, and does not specify that a different product is made, this (or these) transformation is believed to give the same product as the process described by Shiell.
Once a reference teaching product appearing to be substantially identical is made the basis of a rejection, and the examiner presents evidence or reasoning to show inherency, the burden of production shifts to the applicant. "[T]he PTO can require an applicant to prove that the prior art products do not necessarily or inherently possess the characteristics of [their] claimed product. Whether the rejection is based on inherency’ under 35 U.S.C. 102, on prima facie obviousness’ under 35 U.S.C. 103, jointly or alternatively, the burden of proof is the same, and its fairness is evidenced by the PTO’s inability to manufacture products or to obtain and compare prior art products." In re Best, 562 F.2d 1252, 1255, 195 USPQ 4380, 483-34 (CCPA 1977)), see MPEP 2112.
Regarding claim 7, Shiell discloses the material of claim 1, and further discloses that the 4H-Si displays highly oriented multi-crystalline arcs in its XRD pattern which reflect the contributions of the individual grains (p. 3, ¶ 1), indicating that the 4H-Si is in the form of highly oriented 4H-Si grains.
Regarding claims 8 and 9, Shiell discloses the material of claim 1, and further discloses that the material can be powdered (p. 4, ¶ 1) and is comprised of individual grains ~0.5 μm (p. 5, ¶ 2).
Regarding claim 10, Shiell discloses the material of claim 1. The remaining limitations of claim 10 merely recite inherent properties of the 4H-Si phase that is present in the material disclosed by Shiell. Therefore, the material disclosed by Shiell anticipates the material of claim 10.
Regarding claim 20, Shiell discloses a 4H-Si crystalline allotrope of silicon comprising a highly oriented 4H phase silicon microcrystals structure with minimal disordered material (bulk, highly oriented, crystalline 4H hexagonal silicon; abstract; p. 3 describes the product as exhibiting micro-crystallinity).
Regarding claim 21, Shiell discloses a 4H-Si crystalline allotrope of silicon comprising a highly oriented 4H phase silicon microcrystals structure synthesized from Si24 (synthesis of bulk, highly oriented, crystalline 4H hexagonal silicon (4H-Si), through a metastable phase transformation upon heating the single-crystalline Si24 allotrope; abstract; p. 3 describes the product as exhibiting micro-crystallinity).
Regarding claim 22, Shiell discloses a 4H-Si crystalline allotrope of silicon comprising a highly oriented 4H phase silicon microcrystals structure with minimal disordered material (bulk, highly oriented, crystalline 4H hexagonal silicon; abstract; p. 3 describes the product as exhibiting micro-crystallinity). Shiell also discloses that this material can be synthesized from Na4Si24 (p. 10, ¶ 1).
Regarding claim 23, Shiell discloses a 4H-Si crystalline allotrope of silicon comprising a highly oriented 4H phase silicon microcrystals structure synthesized from Si24 (synthesis of bulk, highly oriented, crystalline 4H hexagonal silicon (4H-Si), through a metastable phase transformation upon heating the single-crystalline Si24 allotrope; abstract; p. 3 describes the product as exhibiting micro-crystallinity), and further discloses this material having properties enabling direct use as a semiconductor (4H-Si is a semiconductor; p. 5, ¶ 2).
Regarding claim 24, Shiell discloses a 4H-Si crystalline allotrope of silicon comprising a highly oriented 4H phase silicon microcrystals structure synthesized from Si24 (synthesis of bulk, highly oriented, crystalline 4H hexagonal silicon (4H-Si), through a metastable phase transformation upon heating the single-crystalline Si24 allotrope; abstract; p. 3 describes the product as exhibiting micro-crystallinity), and further discloses this material having 1.2 eV band gap properties enabling direct use as a semiconductor (4H-Si is a semiconductor with an indirect band gap of ~1.2 eV; p. 5, ¶ 2).
Pertinent Prior Art
The following prior art is made of record and not relied upon is considered pertinent to applicant's disclosure:
Pandolfi et al. (“Multi-scale characterization of hexagonal Si-4H: a hierarchical nanostructured material,” arXiv-Materials Science, 6 October 2021, DOI: 10.48550/arXiv.2110.02943) discloses microcrystalline 4H-Si that is comprised of randomly oriented, microcrystalline platelets (large populations of grains with sub-µm dimensions that are packed into a range of orientations; p. 4, ¶ 2). The material of Pandolfi is distinguished from the inventions of the instant claims in that the microcrystals reported by Pandolfi are not highly oriented.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Nicholas A Piro whose telephone number is (571)272-6344. The examiner can normally be reached Mon-Fri, 8:00 am-5:00 pm.
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/NICHOLAS A. PIRO/Assistant Examiner, Art Unit 1738
/PAUL A WARTALOWICZ/Primary Examiner, Art Unit 1735