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 .
Response to Amendment
The amendment filed 4/22/2026 does not place the application in condition for allowance.
The previous rejection under 112(b) is withdrawn.
The previous art rejections over Forrest are withdrawn due to Applicant’s amendment.
The art rejections over Mellor are revised to incorporate new claim limitations.
Claim Rejections - 35 USC § 102
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(s) 1-3, 5, 6, 11, 12, and 14-20 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by US 2020/0328319 to Mellor (of record).
Regarding claims 1, 5, 6, 11, 12, 14, 15, 17, and 18, Mellor teaches a photovoltaic power generation system (¶0056) comprising a solar cell (Fig. 3) which generates electric power, the solar cell comprising
A top cell 3 which is a transparent-type top cell (cell 3 is transparent to light represented by 9 in Figs. 3, 9, ¶0075, 0101), wherein the top cell is connected to a bottom cell 7, the top cell comprises a grating layer 4 (¶0087-0089) on the side of the bottom cell and a gap layer 5 (¶0078) between the grating layer and the bottom cell
The gap layer 5 can isolate electronically the top cell 3 from the bottom cell 7, and the top cell and the bottom cell are electrically isolated (¶0098 describes an embodiment of Fig. 3 which is a four-terminal device, understood to mean that the cells 3 and 7 can be electrically accessed separately).
The grating layer 4 comprises a continuous portion formed of the material of the grating on the side of the top cell (see Marked-up Fig. 3 below, ¶0092), and a mixed portion on the side of the bottom cell which comprises projections of the material of the grating extending away from the continuous portion, a material of layer 5 filling the space between projections. Therefore the side of the top cell of the grating layer 4 has an index of refraction equal to that of the material of the grating, and the side of the bottom cell of the grating layer 4 has an index of refraction that is a weighted average of the two indices of refraction of layers 4 and 5, weighted by the proportion of the volume taken up by the projections to the volume taken up by the air of layer 5. Since the material of grating 4 is a solid, and thus necessarily has a is higher index of refraction than the index of the air of layer 5 (~1), the grating layer 4 is a refractive index-varying layer with a higher refractive index on the side of the top cell and a lower refractive index on the side of the bottom cell.
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Per claim 5, Mellor teaches the limitations of claim 1. The gap layer 5 is formed of air, and therefore necessarily insulative.
Per claim 6, Mellor teaches the limitations of claim 1. The refractive index-varying layer 4 is in direct contact with the top cell 3, and placed on a light-exiting surface of the top cell (Fig. 3, ¶0083).
Per claim 11, Mellor teaches the limitations of claim 1. The gap layer is a layer including air (see reasoning above).
Per claim 12, Mellor teaches the limitations of claim 1. The top cell 3 has a light-absorbing layer whose bandgap is wider than that of the bottom cell 7 (¶0007, 0110).
Per claims 14 and 18, Mellor teaches the limitations of claim 1. The refractive index of the refractive index-varying layer 4 decreases step-likely towards the opposite side of the top cell from the side of the top cell, coincident with the direction towards the side of the bottom cell from the side of the top cell, in a single direction (from the index of the refraction of material 4 to a weighted combination of the indices of refraction of material 4 and that of air).
Per claim 15, Mellor teaches the limitations of claim 1. Mellor teaches that the solar cell further comprises a bottom cell 7 (Fig. 2).
Regarding claims 2, 16, and 19, Mellor teaches a solar cell (Fig. 3), the solar cell comprising
A top cell 3 which is a transparent-type top cell (cell 3 is transparent to light represented by 9 in Figs. 3, 9, ¶0075, 0101), wherein the top cell is connected to a bottom cell 7, the top cell comprises a grating layer 4 (¶0087-0089) on the side of the bottom cell and a gap layer 5 (¶0078) between the grating layer and the bottom cell
The grating layer 4 is not in direct contact with the bottom cell 7 (¶0098).
The grating layer 4 comprises a continuous portion formed of the material of the grating on the side of the top cell (see Marked-up Fig. 3 above, ¶0092), and a mixed portion on the side of the bottom cell which comprises projections of the material of the grating extending away from the continuous portion, a material of layer 5 filling the space between projections. Therefore the side of the top cell of the grating layer 4 has an index of refraction equal to that of the material of the grating, and the side of the bottom cell of the grating layer 4 has an index of refraction that is a weighted average of the two indices of refraction of layers 4 and 5, weighted by the proportion of the volume taken up by the projections to the volume taken up by the air of layer 5. Since the material of grating 4 is a solid, and thus necessarily has a is higher index of refraction than the index of the air of layer 5 (~1), the grating layer 4 is a refractive index-varying layer with a higher refractive index on the side of the top cell and a lower refractive index on the side of the bottom cell.
The gap layer 5 isolates electronically the top cell 3 from the bottom cell 7, and the top cell and the bottom cell are electrically isolated (¶0098 describes an embodiment of Fig. 3 which is a four-terminal device, understood to mean that the cells 3 and 7 can be electrically accessed separately).
Per claim 16, Mellor teaches the limitations of claim 2. Mellor teaches that the solar cell further comprises a bottom cell 7 (Fig. 2).
Per claims 19, Mellor teaches the limitations of claim 2. The refractive index of the refractive index-varying layer 4 decreases step-likely towards the side of the bottom cell from the side of the top cell in a single direction (from the index of the refraction of material 4 to a weighted combination of the indices of refraction of material 4 and that of air).
Regarding claims 3 and 20, Mellor teaches a solar cell (Fig. 3), the solar cell comprising
A top cell 3 which is a transparent-type top cell (cell 3 is transparent to light represented by 9 in Figs. 3, 9, ¶0075, 0101), and a grating layer 4 (¶0087-0089) on the side of the light exiting surface.
The grating layer 4 comprises a continuous portion formed of the material of the grating on the side of the top cell (see Marked-up Fig. 3 above, ¶0092), and a mixed portion on the opposite side of the top cell (equivalent to “side of the bottom cell” in Marked-up Fig. 3) which comprises projections of the material of the grating extending away from the continuous portion, a material of layer 5 filling the space between projections. Therefore the side of the top cell of the grating layer 4 has an index of refraction equal to that of the material of the grating, and the opposite side of the top cell of the grating layer 4 has an index of refraction that is a weighted average of the two indices of refraction of layers 4 and 5, weighted by the proportion of the volume taken up by the projections to the volume taken up by the air of layer 5. Since the material of grating 4 is a solid, and thus necessarily has a is higher index of refraction than the index of the air of layer 5 (~1), the grating layer 4 is a refractive index-varying layer with a higher refractive index on the side of the top cell and a lower refractive index on the opposite side of the top cell.
A gap layer 5 can isolate electronically the top cell 3 from the bottom cell 7, and the top cell and the bottom cell are electrically isolated (¶0098 describes an embodiment of Fig. 3 which is a four-terminal device, understood to mean that the cells 3 and 7 can be electrically accessed separately).
Per claims 20, Mellor teaches the limitations of claim 3. The refractive index of the refractive index-varying layer 4 decreases step-likely towards the side of the bottom cell from the side of the top cell in a single direction (from the index of the refraction of material 4 to a weighted combination of the indices of refraction of material 4 and that of air).
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(s) 4 and 7 is/are rejected under 35 U.S.C. 103 as being unpatentable over Mellor as applied to claim 1 above.
Regarding claim 4, Mellor teaches the limitations of claim 1. It would have been obvious as of the effective filing date of the claimed invention for a person having ordinary skill in the art to form the refractive index-varying layer of an dielectric material (¶0120), as it would have merely been the choice of a known material for its art-recognized purpose. The selection of 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). As such, the refractive index-varying layer of modified-Mellor will be electrically insulative.
Per claim 7, Mellor teaches the limitations of claim 1. As noted, in an interpretation the refractive index of the refractive index-varying layer on the opposite side of the top cell is a weighted average of the refractive index of the material of the grating and the refractive index of air (~1), the material of layer 5. A skilled artisan would choose the material of the grating to fulfill at least the requirement that the grating is transparent (¶0014, 0092, 0019). Regardless, the refractive index of the material of the grating will be larger than that of air.
The volume taken up by the grating, and therefore the proportion of grating material on the opposite side of the top cell, is determined by the geometry of the grating, which may vary from that schematically shown in Figs. 3, 9 (¶0014, 0092). It would have been obvious as of the effective filing date of the claimed invention for a person having ordinary skill in the art to vary the geometry of the grating that partially forms the refractive index-varying layer, in order to achieve optimal scattering from the grating (¶0081, 0089).
“[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.” See In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). The discovery of an optimum value of a known result effective variable, without producing any new or unexpected results, is within the ambit of a person of ordinary skill in the art. See In re Boesch, 205 USPQ 215 (CCPA 1980) (see MPEP § 2144.05, II.).
As such, the claimed result of a refractive index of the surface of the refractive index-varying layer on the opposite side of the top cell being in the claimed range is an obvious result of such optimization.
Claim(s) 8-10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Mellor as applied to claim 1 above, and further in view of US 2016/0126381 to Wang.
Regarding claim 8, Mellor teaches the limitations of claim 1. Mellor teaches that that the top cell 3 is preferably formed of a III-V material (¶0077), but does not recite a refractive index of the top cell. Wang teaches that a refractive index of a III-V material typically ranges from 3-3.6 (¶0147), and that it would have been obvious as of the effective filing date of the claimed invention for a person having ordinary skill in the art to insert voids to reduce the refractive index by a factor of 0.5 in order to enhance light absorption (¶0085, 0089, 0090, 0101).
“[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.” See In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). The discovery of an optimum value of a known result effective variable, without producing any new or unexpected results, is within the ambit of a person of ordinary skill in the art. See In re Boesch, 205 USPQ 215 (CCPA 1980) (see MPEP § 2144.05, II.).
As such, a refractive index of the top cell on the side of the refractive index-varying layer being in the claimed range is an obvious result of optimization.
Regarding claim 9, Mellor teaches the limitations of claim 1. Mellor teaches that that the top cell 3 is preferably formed of a III-V material (¶0077), but does not recite a refractive index of the top cell which is in direct contact with the refractive index-varying layer. Wang teaches that a refractive index of a III-V material typically ranges from 3-3.6 (¶0147), and that it would have been obvious as of the effective filing date of the claimed invention for a person having ordinary skill in the art to insert voids to reduce the refractive index by a factor of 0.5 in order to enhance light absorption (¶0085, 0089, 0090, 0101).
“[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.” See In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). The discovery of an optimum value of a known result effective variable, without producing any new or unexpected results, is within the ambit of a person of ordinary skill in the art. See In re Boesch, 205 USPQ 215 (CCPA 1980) (see MPEP § 2144.05, II.).
As such, a refractive index of the top cell which is in direct contact with the refractive index varying layer being in the claimed range is an obvious result of optimization.
Regarding claim 10, Mellor teaches the limitations of claim 1. Mellor teaches that the material of the refractive index-varying layer is AlInP in an embodiment (¶0092), classified by the reference as a low refractive index material with an index between 1 and 2.5. A member of the top cell 3 which is in direct contact with the refractive index-varying layer is a III-V material (¶0077). Mellor does not recite a refractive index of the top cell member. Wang teaches that a refractive index of a III-V material typically ranges from 3-3.6 (¶0147), and that it would have been obvious as of the effective filing date of the claimed invention for a person having ordinary skill in the art to insert voids to reduce the refractive index by a factor of 0.5 in order to enhance light absorption (¶0085, 0089, 0090, 0101).
“[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.” See In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). The discovery of an optimum value of a known result effective variable, without producing any new or unexpected results, is within the ambit of a person of ordinary skill in the art. See In re Boesch, 205 USPQ 215 (CCPA 1980) (see MPEP § 2144.05, II.).
As such, the absolute value of difference between the member and the layer being between 0.0 and 1.0 is an obvious result of optimization.
Claim(s) 13 is/are rejected under 35 U.S.C. 103 as being unpatentable over Mellor as applied to claim 1 above, and further in view of US 2024/0381575 to Chae.
Regarding claim 13, Mellor teaches the limitations of claim 1. Mellor does not teach a holding member securing the top cell with the bottom cell. Chae teaches that it would have been obvious as of the effective filing date of the claimed invention for a person having ordinary skill in the art to apply a holding member (440 of Fig. 4D) to a similar solar cell to ensure moisture resistance (¶0044).
Response to Arguments
Applicant's arguments filed 4/22/2026 have been fully considered but they are not persuasive.
The examiner has withdrawn the previous 112(b) rejection of claim 7. Particularly, the examiner points out that a refractive index between 1.0 and 1.1 can be achieved for a surface with a particular arrangement of concavo-convex elements described on p. 61, 65 of the instant specification.
Applicant argues that Mellor’s layer 4, described as a diffraction grating in the text, does not read on a refractive index-varying layer. A skilled artisan would understand that a diffraction grating comprises a repeating pattern of material, which functions because of the periodicity of the pattern and the contrast of the index of refraction of the material and the index of the refraction of the abutting material. Applicant correctly characterizes that the material of the continuous portion of 4 is uniform. The repeating hashed portion of Mellor’s Fig. 3 would be familiar to a skilled artisan as a schematic depiction of a diffraction grating. Further, the periodic portion of 4 is also made of the material of the continuous portion, and the abutting material is air in an embodiment. Within the broadest reasonable limitation, the element 4 comprises a continuous layer having an index of refraction of the solid material of the diffraction grating, and a discontinuous layer that alternates between the material of the solid material and air, having an index of refraction that can be reasonably construed to be an average of that of the solid material and air, with each index weighted by the proportion of volume taken up by each component.
Applicant seems to argue that it is improper to identify the discontinuous layer as distinct from the continuous layer, as the Mellor reference does not identify these layers as such. However, such an interpretation is reasonable within the broadest reasonable interpretation when read in light of the instant disclosure. In fact, this interpretation is necessary to understand the embodiment of instant Figure 10. In the description of that embodiment, including the relevant text in the specification, 31 is described as a refractive index varying layer. Elsewhere, an embodiment of a refractive index varying layer is described as a member whose refractive index varies due to unevenness (specifically paragraph [0068] on p. 16 of the specification). The disclosure does not specify that the concave/convex portions that form the unevenness are of a different material than the higher refractive index portion of the layer. Therefore a person having ordinary skill in the art could only conclude that the layer 31 of Figure 10 has a varying refractive index because of the alternation of the index of refraction of the material of concave/convex portions and the material abutting those portions, which is also the material of a gap layer when it is present.
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 Ryan S Cannon whose telephone number is (571)270-7186. The examiner can normally be reached M-F, 8:30am-5:30pm PST.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Jeffrey Barton can be reached at (571) 272-1307. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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Ryan S. Cannon
Primary Examiner
Art Unit 1726
/RYAN S CANNON/ Primary Examiner, Art Unit 1726
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