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 .
Status of Claims
Claims 1-17 are pending and examined below.
Claim Rejections - 35 USC § 103
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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
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 non-obviousness.
Claims 1-8 and 11-17 are rejected under 35 U.S.C. 103 as being unpatentable over Zhang (CN 110137274) in view of Huang et al. (US 2022/0115545) and Padhamnath et al. (US 2024/0079506) as evidenced by Li et al. (Comparative study on front emitter and rear emitter n-type silicon heterojunction solar cells: The role of folded electrical fields).
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The above figure is a marked-up fig. 40, applicant’s elected species.
Regarding claim 1, Zhang discloses a solar cell (shown in fig. 1, marked-up Zhang fig. 1 below), comprising:
a doped semiconductor substrate (1) comprising a first (back) surface and a second (front) surface opposite to each other (shown in fig. 1),
the second surface comprising a passivation contact region (under the electrode 9) and a passivation region adjacent to each other (outside of the electrode region) (see marked-up fig 1 below) (see para [0032] and [0036]);
a first tunneling passivation structure (6, 7) disposed on the first (back) surface, the first tunneling passivation structure (6, 7) comprising a first tunnel layer (6) and a first passivation contact layer (7) stacked in a direction away from the semiconductor substrate (shown in fig. 1, see para [0032] and [0036]),
a second tunneling passivation structure (4, 3, 2) disposed on the second (front) surface and located in the passivation contact region of the second surface (see markup of fig. 1, para [0032] and [0036]),
the second tunneling passivation structure (4, 3, 2) comprising a second tunnel layer (2) and a second passivation contact layer (3) stacked on the passivation contact region (see markup of fig. 1); and
a third tunnel layer (5) and a third passivation layer (4) stacked on the passivation region of the second surface, where the thickness of the passivation layer (3) is controlled at 30-50 nm, (see para [0015]).
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The above is a marked-up fig. 1 of the prior art Zhang.
Zhang does not disclose a thickness of the third passivation layer (4) being less than a thickness of the second passivation contact layer (3).
The court has held it would be obvious to a person having ordinary skill in the art to optimize the relative thickness of layer 4 and layer 3 of Zhang as differences in a variable will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such variable is critical. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
Further, Zhang does not disclose wherein the substrate is an n-type semiconductor, nor wherein the oppositely doped emitter, i.e., p-type doped passivation contact layer, is on the first surface, i.e., back/rear side. Note: Zhang discloses a p-type substrate with an n-type emitter on the front side (second surface).
Huang is analogous art to Zhang as Huang is directed to a tunnel oxide passivated contact solar cell comprising a first type doped substrate and a second type doped semiconductor film (emitter) (see abstract). Huang discloses that the first type doped substrate may be either N-type doped semiconductor or a P-type doped semiconductor, wherein the emitter doped semiconductor film is oppositely doped (see para [0014]-[0015]).
The court has held it would be obvious to a person having ordinary skill in the art to modify Zhang to have an n-type doped semiconductor and a p-type doped emitter as Huang discloses choosing between a finite number of identified, predictable solutions, (i.e., either an n-type doped substrate or a p-type doped substrate with an oppositely doped emitter), one of ordinary skill in the art would have found obvious to pursue the known options with a reasonable expectation of success.
Zhang as modified by Huang does not disclose a back or rear side emitter.
Padhamnath is analogous art to modified Zhang as Padhamnath discloses a tunnel oxide passivated contact solar cell comprising either an n or p doped substrate and an oppositely doped emitter (see abstract and para [0054]). Further, Padhamnath discloses the emitter may be on the front side (fig. 1A) or the rear (fig. 1B) (see para [0104], e.g. “manufacturing of n-type rear junction passivated contact solar cells using carrier selective alloyed (p.sup.+) silicon layers (e.g. the solar cell 120 of FIG. 1B)”). The reasons for choosing either a front or back side emitter is well-known in the art as evidenced by Li (see entire document). Specifically, a rear emitter junction solar cell had a higher open-circuit voltage, fill factor, and conversion efficiency (see Li Highlights, page 1).
It would be obvious for a person having skill in the art to modify the solar cell of modified Zhang to be a rear emitter solar cell, (i.e. layers 3 and 4, and substrate 1, n-type doped semiconductor, layer 7 p-type doped emitter), because a rear side emitter has certain advantages of a higher open-circuit voltage, fill factor, and conversion efficiency.
Regarding claim 2, modified Zhang discloses a solar cell according to claim 1, wherein a first distance between the passivation contact region of the second surface and the first surface is represented by L1, and a second distance between the passivation region of the second surface and the first surface is represented by L2, L1 and L2 satisfy 0 < L1-L2 < 1 µm, (i.e., L1-L2 =0, Zhang, as the passivation contact region comprises layers 4, 3 and 2, the distance from the bottom portion of layer 4 and the surface of the substrate 1 is exactly the same) (see Zhang para [0015]-[0016], [0032] and [0036].
Regarding claim 3, modified Zhang discloses a solar cell according to claim 1, but does not disclose wherein the thickness of the second passivation contact layer (layer 3 of Zhang) is in a range from 90 nm to 300 nm. Zhang discloses the second passivation contact layer (3) is 30 to 50 nm (see Zhang para [0015]-[0016]).
The court has held it would be obvious to a person having ordinary skill in the art to optimize the thickness of layer 3 of Zhang as differences in a variable will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such variable is critical. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
Regarding claim 4, modified Zhang discloses a solar cell according to claim 1, but does not disclose wherein the semiconductor substrate comprises a first diffusion region, and an orthographic projection of the second tunneling passivation structure projected on the semiconductor substrate overlaps with the first diffusion region.
Zhang discloses layer 4, a semiconductor layer, n doped semiconductor (see discussion claim 1), but does not disclose the layer is formed by diffusion (see Zhang para [0015]-[0016], [0032] and [0036]).
Padhamnath discloses the doped semiconductor layer (e.g., layer 124 of fig. 1B) may be formed by diffusion of the dopant (see para [0076]). Zhang as modified by Padhamnath discloses the layer 4 shown in the marked-up fig. 1 of Zhang to be a first diffusion region in the passivated contact region (note layer 4 is integrally also formed under the passivation region as a second diffusion region). Thus resulting in the orthographic projection of the second tunneling passivation structure projected on the semiconductor substrate overlaps with the first diffusion region.
The court has held it would be obvious to a person having ordinary skill in the art to combine prior art elements (i.e. the semiconductor layer of Zhang with the diffusion process of Padhamnath) according to known methods in the art (see MPEP § 2144.03, diffusion into a substrate), wherein the result is predictable, i.e., a plus-doped semiconductor conductive region near the electrodes.
Regarding claim 5, modified Zhang discloses a solar cell according to claim 4, wherein the semiconductor substrate comprises a second diffusion region (Zhang layer 4 formed by diffusion, see discussion of claim 4), the second diffusion region is in contact with the first diffusion region (i.e., integrally formed, see discussion of claim 4), and an orthographic projection of the second tunneling passivation structure projected on the semiconductor substrate does not overlap with the second diffusion region, i.e., the portion of layer 4 in the passivation region shown in the mark-up of Zhang fig. 1 above, see Zhang para [0015]-[0016], [0032] and [0036]).
Regarding claim 6, modified Zhang discloses a solar cell according to claim 1, wherein the third tunnel layer and the second tunnel layer are one integrated structure, (i.e., tunnel layer 5 and tunnel layer 2 are shown integrated as shown in marked-up fig. 1 of Zhang above, see para [0015]-[0016], [0032] and [0036]).
Note that the examiner has elected not to examiner optional limitations. Further, it appears the optional limitation “and/or the third passivation layer and the second passivation contact layer are one integrated structure” is not within the elected species.
Regarding claim 7, modified Zhang discloses a solar cell according to claim 1, but does not disclose wherein a thickness ratio of the second passivation contact layer to the third passivation layer is in a range from 5 to 30 (see discussion of claim 1, Zhang para [0015]-[0016], [0032] and [0036]).
The court has held it would be obvious to a person having ordinary skill in the art to optimize the relative thickness of layer 4 and layer 3 of Zhang as differences in a variable will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such variable is critical. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
Regarding claim 8, modified Zhang discloses a solar cell according to claim 1, but does not disclose wherein the thickness of the third passivation layer is in a range from 10 nm to 20 nm (see Zhang para [0015]-[0016], [0032] and [0036]).
The court has held it would be obvious to a person having ordinary skill in the art to optimize the thickness of layer 4 of Zhang as differences in a variable will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such variable is critical. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
Regarding claim 11, modified Zhang discloses a solar cell according to claim 1, wherein the second surface in both the passivation contact region and the passivation region comprises pyramidal textured structures (shown in fig. 1, see Zhang para [0038]).
Regarding claim 12, modified Zhang discloses a solar cell according to claim 1, further comprising a first electrode (10) and a second electrode (9), wherein the first electrode is electrically connected to the first tunneling passivation structure (i.e., layers 6,7), and the second electrode (9) is electrically connected to the second tunneling passivation structure (2, 3, 4) (see Zhang fig. 1, para [0032].
Regarding claim 13, modified Zhang discloses a solar cell according to claim 1, further comprising a second passivation layer (8), the second passivation layer is located on the second surface (see Zhang fig.1 mark-up above, see para [0032]).
Padhamnath discloses a first passivation layer and wherein the first passivation layer is located on the first surface. Padhamnath discloses two electrodes instead of a back surface electrode. Consequently, Padhamnath discloses the first passivation layer (134) located on the first surface (shown in fig. 1B, para [0030], [0048]-[0049], [0106]).
The Court has held it would be obvious to a person having ordinary skill in the art to substitute one known device (i.e. a rear grid (two) electrode with a passivation surface layer) for another known device (a back surface electrode), wherein the result is predictable, i.e., conduction of current.
Regarding claim 14, modified Zhang discloses a solar cell according to claim 13, further comprising a first anti-reflective layer and a second anti-reflective layer, wherein the first anti-reflective layer is located on the first passivation layer, and the second anti-reflective layer is located on the second passivation layer (see Padhamnath para [0106]).
The Courts have held that it would be obvious to a person having ordinary skill in the art to select a known material, which is based upon its suitability for the intended use, is within the ambit of one of ordinary skill in the art. See In re Leshin, 125 USPQ 416 (CCPA 1960) (see MPEP § 2144.07).
Regarding claim 15, modified Zhang discloses a solar cell according to claim 1, wherein the first tunneling passivation structure is in contact with the first surface, and the second tunneling passivation structure is in contact with the passivation contact region of the second surface (shown in Zhang fig. 1 mark-up, see para [0015]-[0016], [0032] and [0036]).
Regarding claims 16 and 17, modified Zhang discloses a solar cell according to claim 1. Modified Zhang does not disclose a photovoltaic module, comprising the solar cell according to claim 1 (claim 16), nor a photovoltaic system, comprising the module of claim 16 (claim 17). The art of forming a silicon solar cell into a module and combined into a photovoltaic system is a well-known expedient in the art as forming a module and combining into a system increases the utility of the solar cell. See MPEP § 2144.03.
It would be obvious to a person having ordinary skill in the art to modify the solar cell disclosed by modified Zhang by incorporating the solar cell into a module and the module into a system because incorporation into a module and system increases the utility of the solar cell.
Allowable Subject Matter
Claims 9 and 10 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter: The prior art does not disclose wherein the second passivation contact layer comprises a first passivation contact sub-layer, a barrier layer, and a second passivation contact sub-layer, stacked in a direction away from the semiconductor substrate. Nor is there any reason to modify the prior art to form this structure. The claim structure is shown in applicant’s elected invention, fig. 42, marked-up, below.
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Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JAYNE L MERSHON whose telephone number is (571)270-7869. The examiner can normally be reached 10:00 to 6:00 M-F.
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JAYNE L. MERSHON
Primary Examiner
Art Unit 1721
/JAYNE L MERSHON/ Primary Examiner, Art Unit 1721
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