DETAILED ACTION
(1)
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 . Applicant’s amendment filed December 4, 2025, is entered. Applicant amended claims 1, 9, 10 and 13. No new matter is entered. Claims 1-12 and 20 are pending before the Office for review. Claims 13-19 remain withdrawn in response to a restriction requirement.
(2)
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.
Claims 1, 2, 5-9, 11 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Lin et al. (U.S. Publication No. 2025/0169224 A1) in view of Rana et al. (WO 2014/179368) and Hu et al. (U.S. Publication No. 2025/0048778). Examiner notes CN 11605331 A, which is cited in the information disclosure statement, is in the same patent family as Lin et al. Examiner also notes Hu et al. is in the same patent family as CN 116666468 A, which is cited in Applicant’s information disclosure statement.
With respect to claims 1, 8 and 9, Lin teaches a back contact solar cell (figure 7) comprising a semiconductor substrate (1) having a light receiving surface (bottom) and a shady surface (top) that are opposite to each other, the shady surface comprising first and second polarity regions that are alternately arranged in a first direction. Figure 7 and Paragraphs 59 and 113-120.
Lin further teaches a first functional layer comprising a first passivation layer (2) and a first doped semiconductor layer (n-type; 3) are formed in the first polarity region and stacked in a direction away from the semiconductor substrate. Figure 7 and Paragraph 113. Lin further teaches a surface of the doped substrate close to the first passivation layer is a polished surface. Paragraph 22.
Lin next teaches a second functional layer formed in the second functional region and comprising a second passivation layer (4) and a second doped semiconductor layer (p-type; 5) stacked in a direction away from the semiconductor substrate, the first and second doped semiconductor layers having opposite doping types. Figure 7 and Paragraph 113.
Finally, Lin teaches first and second electrode structures (10) formed on a side of the first functional layer away from the semiconductor substrate and a side of the second functional layer away from the semiconductor substrate, respectively. Figure 7 and Paragraph 59.
Lin is silent as to whether the back contact solar cell comprises a laser protection layer formed on a side of the second functional layer facing away from the semiconductor substrate, as required by claim 1.
However, Rana, which deals with patterned solar cells, teaches a patterning method comprising laser processing innovations to improve solar cell efficiency. Paragraph 152. The method utilizes laser patterning with a laser absorbent hard mask in combination with wet etching to form patterned solar cell doped regions. Paragraph 152. Specifically, Rana teaches high efficiency back-contact solar cells with interdigitated metallization formed over alternating base and emitter regions (claimed first and second functional regions) require very fine patterning and that laser ablation is used to obtain small size pattern dimensions. Paragraph 153.
Rana further teaches a laser protection layer in the form of a hard mask layer is deposited onto the to-be patterned region, the laser protection layer protects the underlying layers from damage to allow for damage-free laser patterning, and then wet etching is performed for selective film removal. Paragraphs 153-155.
Lin teaches a protective ink is used to facilitate wet etching of the solar cell layers and that laser ablation is also performed to pattern the layers. Paragraphs 115 and 117.
It would have been obvious to one ordinarily skilled in the art at a time before the effective filing date of the claimed invention to position a laser protection layer (Rana’s hard mask layer) on a side of the second functional layer away from the semiconductor substrate because Rana teaches doing so facilitates laser ablation to obtain small size pattern dimensions without damaging the underlying layers.
Furthermore, when the hard mark is positioned, as taught by Rana, the hard mask exposes an electrode contact region of the second functional layer to facilitate electrode contact formation, as taught by Lin in figure 7. Specifically, one ordinarily skilled in the art at a time before the effective filing date of the claimed invention would understand the hard mask layer would have to be deposited consistent with Lin’s patterning, wherein the second functional layer is exposed to facilitate electrode contact formation. Figure 7.
Modified Lin teaches the back contact solar cell but is silent as to whether it is structured to meet the specific stacking and layer requirements.
However, Hu, which deals with back contact solar cells, teaches a first and second functional layer arrangement wherein the second functional layer (121, 122) is positioned further within the substrate than the first functional layer (111, 112), meaning a first distance between the surface of the first polarity region and the light-receiving surface is greater than a second distance between the surface of the second polarity region (first and second polarity regions being associated with the first and second functional layers). Figure 1 and Paragraphs 29 and 37.
Hu further teaches the semiconductor substrate comprises a doped substrate layer (113) located in the first polarity region (positioned adjacent the first functional layer) and in contact with the first passivation layer (111), the doped substrate layer having the same doping type as the first doped semiconductor layer (as noted due to their stacked proximity). Figure 1 and Paragraphs 29 and 41. The doped substrate layer (113) is adjacent to the second passivation layer (121) formed in the second polarity region in the first direction. Figure 1 and Paragraph 29.
Regarding the distance and the thickness range, as per the MPEP, “where the only difference between the prior art and the claims [is] a recitation of relative dimensions of the claimed device and a device having the claimed relative dimensions would not perform differently than the prior art device, the claimed device [is[ not patentably distinct from the prior art device.” MPEP 2144.04(IV)(A) (internal citation omitted). In this case, the first and second functional layers perform their hole/charge generation functions independent of their respective distances from the light-receiving surface and the substrate doping layer performs its function independent of its specific thickness.
Hu teaches a back contact solar cell having these structural features is associated with improved efficiency and reliability and increased open circuit voltage. Paragraph 5.
Therefore, it would have been obvious to one ordinarily skilled in the art at a time before the effective filing date of the claimed invention to modify Lin’s back contact solar cell to incorporate the structural features of Hu therein because Hu teaches these features are associated with improved efficiency and reliability and increased open circuit voltage, meaning the modification has a reasonable expectation of success.
With respect to claim 2, modified Lin teaches the laser protection layer (hard mask layer) is formed on the side of the second functional layer away from the semiconductor substrate and exposes the electrode contact region of the second functional layer. Lin, Figure 7 and Rana, Paragraphs 153-155. Modified Lin further teaches the laser protection layer is a multi-layer comprising silicon nitride and amorphous silicon or any combination thereof. Rana, Paragraph 155. Accordingly, when the laser protection layer is a multi-layer comprising silicon nitride and amorphous silicon, as taught by modified Lin, an insulation dielectric layer (silicon nitride) is formed on the side of the second functional layer away from the semiconductor substrate and a laser absorption layer (amorphous silicon) is formed on a side of the insulation dielectric layer away from the semiconductor substrate. Lin, Figure 7 and Rana, Paragraph 155.
With respect to claim 5, modified Lin teaches the second functional layer (4, 5) at least partially extends into the first polarity region (covered by first functional layers; 2, 3), a first orthographic projection of the first functional layer on the semiconductor substrate at least partially overlaps with a second orthographic projection of the second function l layer on the semiconductor substrate and a part of the first functional layer overlapping with a part of the second functional layer is in direct contact with the part of the second functional layer. Figure 7 and Paragraphs 59 and 113-120.
With respect to claim 6, modified Lin teaches the first and second electrode structures extend towards two sides. Figure 7. Modified Lin further teaches an opening (unoccupied area) is formed between the first and second electrode structure adjacent to the first electrode structure. Figure 7. Modified Lin further teaches a third orthographic projection of the opening on the semiconductor substrate is located within an orthographic projection of the lase protection layer on the semiconductor substrate, wherein the laser protection layer coverage includes at least the space adjacent the second electrode, as evidenced by the mask taught by Lin. Lin, Figure 7 and Paragraphs 59 and 113-120 and Rana, Paragraphs 153-155.
With respect to claim 7, Examiner notes that the claim is a product-by-process claim. “If the product in the product-by-process is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process.” In re Thorpe, 777 F.2d 695, 698 (Fed. Cir. 1985); MPEP 2113. In this case, the claim is a product-by-process claim to the extent “polished” requires a specific process.
In this case, modified Lin teaches the light-receiving surface is textured and each surface of the first and second polarity regions is smooth. Figure 7.
With respect to claim 11, modified Lin teaches the first passivation layer comprises tunneling oxide and has a thickness of 1.5 nm, the first doped layer comprises polycrystalline (polysilicon) silicon and has a thickness of 150 nm, the second passivation layer comprises intrinsic amorphous silicon and has a thickness of 10 nm and the second doped semiconductor layer comprises amorphous silicon and has a thickness of 20 nm. Paragraph 113.
With respect to claim 20, modified Lin teaches a photovoltaic module including the back contact solar cell, which is a battery assembly within the scope of the claimed invention. Paragraph 43.
(3)
Claims 3 and 4 are rejected under 35 U.S.C. 103 as being unpatentable over Lin et al. (U.S. Publication No. 2025/0169224 A1) in view of Rana et al. (WO 2014/179368) and Hu et al. (U.S. Publication No. 2025/0048778), as applied to claims 1, 2, 5-9, 11 and 20 above, and further in view of Xie et al. (CN 116487454 A). The citations to Xie et al. refer to the included English language machine translation.
With respect to claims 3 and 4, modified Lin teaches the laser protection layer is a multi-layer comprising silicon nitride and amorphous silicon. Lin, Figure 7 and Rana, Paragraph 155.
Modified Lin is silent as to the thickness of the two layers.
However, Xie, which deals with back contact solar cells formed using laser ablation technique, teaches a laser absorption layer and protective layer stack formed of amorphous silicon (thickness of 3-7 nm) and silicon nitride (thickness of 8-20 nm), respectively. Page 6, Fourth paragraph. As per the MPEP, "where the claimed ranges overlap or lie inside ranges disclosed by the prior art a prima facie case of obviousness exists." MPEP 2144.05(I) (internal citation omitted).
It would have been obvious to one ordinarily skilled in the art at a time before the effective filing date of the claimed invention the combination of modified Lin with Xie is the use of a known technique to improve a similar back contact solar cell in the same way. Both modified Lin and Xie are directed toward back contact solar cells comprising laser absorption layers that are a stack of amorphous silicon and silicon nitride. Xie teaches a thickness of 3-7 nm and 8-20 nm is effective for each layer, respectively. It would have been obvious to one ordinarily skilled in the art at a time before the effective filing date of the claimed invention to form modified Lin’s layers with the same thicknesses as Xie because Xie teaches this to be an effective layer thickness for a laser absorption stack in the production of back contact solar cells, meaning the modification has a reasonable expectation of success.
(4)
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Lin et al. (U.S. Publication No. 2025/0169224 A1) in view of Rana et al. (WO 2014/179368) and Hu et al. (U.S. Publication No. 2025/0048778), as applied to claims 1, 2, 5-9, 11 and 20 above, and further in view of Nakashima et al. (U.S. Publication No. 2008/0023068).
With respect to claim 10, modified Lin teaches the first and second electrode structures comprises a first or second electroconductive layer arranged on a side of the first or second doped semiconductor layer away from the first or second passivation layer and a first or second electrode arranged on a side of the first or second electroconductive layer away from the first or second doped semiconductor layer, wherein a material of the first and second electroconductive layer comprises indium oxide and the first and second electroconductive layer is doped with titanium. Figure 7 and Paragraph 77.
Modified Lin is silent as to the thickness of the electroconductive layer.
However, Nakashima, which deals with solar cells, teaches 100 nm to be an effective thickness for the indium oxide electroconductive layer of a solar cell. Paragraph 41. As per the MPEP, "where the claimed ranges overlap or lie inside ranges disclosed by the prior art a prima facie case of obviousness exists." MPEP 2144.05(I) (internal citation omitted).
It would have been obvious to one ordinarily skilled in the art at a time before the effective filing date of the claimed invention the combination of modified Lin with Nakashima is the use of a known technique to improve a similar solar cell in the same way. Both modified Lin and Nakashima teach solar cells comprising indium oxide electroconductive layers. Nakashima teaches 100 nm is an effective thickness for such a layer. Therefore, it would have been obvious to one ordinarily skilled in the art at a time before the effective filing date of the claimed invention to form modified Lin’s indium oxide layer with a thickness of 100 nm because Nakashima teaches this to be an effective layer thickness, meaning the modification has a reasonable expectation of success.
(5)
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Lin et al. (U.S. Publication No. 2025/0169224 A1) in view of Rana et al. (WO 2014/179368) and Hu et al. (U.S. Publication No. 2025/0048778), as applied to claims 1, 2, 5-9, 11 and 20 above, and further in view of Ko et al. (U.S. Publication No. 2011/0126906).
With respect to claim 12, modified Lin teaches a front film layer (7) is located on the light receiving surface, wherein the front film layer comprises a multi-layer of a silicon dielectric passivation layer and a silicon dielectric anti-reflection layer stacked in the direction away from the semiconductor substrate. Figure 7 and Paragraphs 59 and 113. The passivation layer is the equivalent of the third passivation layer and the anti-reflection layer is the anti-reflection layer. Paragraph 113. The passivation layer can be a silicon oxide. Paragraph 91.
Modified Lin is explicitly silent as to the material of the anti-reflection layer.
However, Ko, which deals with solar cells, teaches aluminum oxide is an effective anti-reflection layer material due to its low light reflectance. Paragraph 44.
Therefore, it would have been obvious to one ordinarily skilled in the art at a time before the effective filing date of the claimed invention to use aluminum oxide for the anti-reflection layer material because Ko teaches it has low light reflectance.
(6)
Response to Arguments
Applicant’s arguments are not persuasive. Applicant’s argument is not persuasive because it misunderstands the scope of the claimed invention. Applicant argues amended claim 1 requires the doped substrate layer is adjacent the passivation layer formed in the second polarity region in the first direction. Applicant further argues Lin does not teach this feature because Lin is silent on providing any doped substrate layer located in the first polarity region and in contact with the first passivation layer. Applicant’s argument misstates the claim scope because “contact,” particularly “direct contact” or “direct adjacency” is not a feature of the claimed invention. The “adjacent” requirement of the claimed invention defines a spatial relationship, but it is not specific or descriptive enough by itself to require contact or direct contact.
Applicant’s argument also fails to consider the Hu addresses these alleged deficiencies when the broadest reasonable interpretation of “adjacent” is considered. To that point, Applicant argues Hu does not teach a polished surface. However, as noted above, Lin teaches this feature. In response to Applicant’s arguments against the references individually, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986).
(7)
Conclusion
THIS ACTION IS MADE FINAL. 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 ELI S MEKHLIN whose telephone number is (571)270-7597. The examiner can normally be reached Monday-Friday 7:00 am to 5:00 pm EST.
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/ELI S MEKHLIN/Primary Examiner, Art Unit 1759