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 .
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.
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 nonobviousness.
Claims 1, 6, 7, and 10-11 are rejected under 35 U.S.C. 103 as being unpatentable over Yangzhou Changelight Co., Ltd. (CN 107546287 A, cited on 06/27/2025 IDS, hereinafter referred to Yangzhou, see attached machine translation) in view of Yan et al. (CN 218677183, see attached machine translation), as evidenced by Rohr et al. (US 2003/0089392).
Regarding claim 1, Yangzhou discloses a multijunction solar cell structure ([0046]) comprising a substrate ([0056] discloses a Ge substrate; [0064]) and a plurality of subcells stacked on the substrate ([0057]), wherein the plurality of subcells comprise an InGaAs subcell ([0069],[0096]), wherein the InGaAs subcell comprises an InjGaAs base region ([0069]; j=1) and an InjGaAs emitter region ([0096]; j=1) disposed in a direction away from the substrate ([0096],[0097]), and a multiple quantum well (MQW) structure disposed between the InjGaAs base region and the InjGaAs emitter region ([0070]), wherein the InjGaAs base region is doped with a first conductivity type ([0069]) and the InjGaAs emitter region is doped with a second conductivity type ([0096]), wherein the MQW structure comprises alternately stacked InxGaAs quantum well layers and InkGaAsPy barrier layers ([0077]; x=1, k=0, y=1), and an InwGaAsPz step barrier layer disposed between an InxGaAs quantum well layer and an InkGaAsPy barrier layer ([0077] discloses a buffer transition layer; w=0, z=0), and wherein j, x, y, k, w, and z are numbers greater than or equal to zero ([0069],[0077],[0096]; j=1, x=1, y=1, k=0, w=0, z=0).
While Yangzhou does disclose a high degree of lattice matching between the layers, the material of the potential well layer 231 in the multi-quantum well structure 23 may be InxGa1-xAs, the material of the barrier layer 233 may be GaAs1-yPy, wherein the value of x ranges from 0 to 0.3, and the value of y ranges from 0 to 0.5 ([0052]), and further discloses the buffer transition layer can effectively avoid uncontrolled stress relaxation and unclear interface between the strain potential well layer and the strain potential barrier layer when they are directly connected, and that this allows for more precise stress balance, reduces defects, and improves the problem of atomic interdiffusion at the interface between the potential well layer and potential barrier layer in a multi-quantum well structure ([0035]); Yangzhou does not explicitly disclose a bandgap of the InwGaAsPz step barrier layer lies between a bandgap of the InxGaAs quantum well layer and a bandgap of the InkGaAsPy barrier layer.
Yan discloses a multiple quantum well structure used in optoelectronic devices ([n0001],[n0003]) and further discloses a lattice constant of a step barrier layer lies between a lattice constant of a quantum well layer and a lattice constant of a barrier layer ([n0005]).
It would have been obvious to one of ordinary skill in the art at the time the invention was filed to form the buffer transition layer of Yangzhou with a lattice constant lying between a lattice constant of the quantum well layer and a lattice constant of the barrier layer, as disclosed by Yan, because as taught by Yan, internal stress of the multi-quantum well structure is reduced and recombination efficiency of charge carriers is improved ([n0005]).
With regard to the limitation “a bandgap of the InwGaAsPz step barrier layer lies between a bandgap of the InxGaAs quantum well layer and a bandgap of the InkGaAsPy barrier layer,” as evidenced by Rohr, there is a linear relationship between bandgap values and lattice constants in InGaAsP compounds (Fig. 7), and therefore, one skilled in the art would expect a bandgap of the InwGaAsPz step barrier layer of modified Yangzhou to lie between a bandgap of the InxGaAs quantum well layer and a bandgap of the InkGaAsPy barrier layer (Yan - [n0005] discloses a lattice constant of a step barrier layer lies between a lattice constant of a quantum well layer and the lattice constant of a barrier layer as set forth above).
Regarding claim 6, modified Yangzhou discloses all the claim limitations as set forth above. Modified Yangzhou further discloses a thickness of the InxGaAs quantum well layer is 1 nm to 10 nm (Yangzhou – [0077]), a thickness of the InkGaAsPy barrier layer is 1 to 20 nm (Yangzhou – [0077]), and a thickness of the step barrier layer InwGaAsPz is 0.3 – 3 nm (Yangzhou – [0077]). It would have been obvious to one of ordinary skill in the art at the time of invention to have selected the overlapping portion of the ranges disclosed by the reference because selection of overlapping portion of ranges has been held to be a prima facie case of obviousness. In re Malagari, 182 USPQ 549.
Regarding claim 7, modified Yangzhou discloses all the claim limitations as set forth above. Modified Yangzhou further discloses x ranges from 0 to 0.3, and y ranges from 0 to 0.5 (Yangzhou – [0077]). It would have been obvious to one of ordinary skill in the art at the time of invention to have selected the overlapping portion of the ranges disclosed by the reference because selection of overlapping portion of ranges has been held to be a prima facie case of obviousness. In re Malagari, 182 USPQ 549.
Regarding claim 10, modified Yangzhou discloses all the claim limitations as set forth above. Modified Yangzhou further discloses the plurality of subcells comprise a first subcell, a second subcell, and a third sub cell arranged in a direction away from the substrate (Yangzhou – [0012],[0023]), wherein the first subcell is a Ge subcell (Yangzhou – [0014]), the second subcell is the InGaAs subcell (Yangzhou – [0014]), and the third subcell is an (Al)GaInP subcell (Yangzhou – [0014]), and wherein a first tunnel junction is disposed between the first subcell and the second subcell (Yangzhou – [0012]), and a second tunnel junction is disposed between the second subcell and the third subcell (Yangzhou – [0012]).
Regarding claim 11, modified Yangzhou discloses all the claim limitations as set forth above. Modified Yangzhou further discloses the first conductivity type is p-type (Yangzhou – [0069]), and the second conductivity type is n-type (Yangzhou – [0096]).
Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over Yangzhou Changelight Co., Ltd. (CN 107546287 A, cited on 06/27/2025 IDS, hereinafter referred to Yangzhou, see attached machine translation) in view of Yan et al. (CN 218677183, see attached machine translation), as evidenced by Rohr et al. (US 2003/0089392), as applied to claim 1 above, and further in view of Chiou et al. (US 2007/0151595).
Regarding claim 3, modified Yangzhou discloses all the claim limitations as set forth above.
While modified Yangzhou does disclose, in the MQW structure, k=0, the InkGaAsPy barrier layer is a GaAsP barrier layer (Yangzhou - [0077]; k=0, y=1), w=0 (Yangzhou - [0077] discloses a buffer transition layer; w=0, z=0), and the InwGaAsPz step barrier layer is a GaAsP step barrier layer (Yangzhou - [0077] discloses a buffer transition layer; w=0, z=0), wherein z < y (Yangzhou - [0069],[0077],[0096]; j=1, x=1, y=1, k=0, w=0, z=0); modified Yangzhou does not explicitly disclose j=0, the InjGaAs base region is a GaAs base region, and the InjGaAs emitter region is a GaAs emitter region.
Chiou discloses a multijunction solar cell structure ([0016],[0025]) and further discloses a GaAs base region and a GaAs emitter region ([0025]).
It would have been obvious to one of ordinary skill in the art at the time the invention was filed to form the base and emitter regions of modified Yangzhou with GaAs, as disclosed by Chiou, because as evidenced by Chiou, the use of GaAs to form the base and emitter regions of a subcell of a multijunction solar cell structure amounts to the use of a known material in the art for its intended purpose to achieve an expected result, and one skilled in the art would have a reasonable expectation of success when forming the base and emitter regions of modified Yangzhou with GaAs based on the teaching of Chiou.
Claims 4 and 5 are rejected under 35 U.S.C. 103 as being unpatentable over Yangzhou Changelight Co., Ltd. (CN 107546287 A, cited on 06/27/2025 IDS, hereinafter referred to Yangzhou, see attached machine translation) in view of Yan et al. (CN 218677183, see attached machine translation), as evidenced by Rohr et al. (US 2003/0089392), as applied to claim 1 above, and further in view of Rohr et al. (US 2003/0089392).
Regarding claim 4, modified Yangzhou discloses all the claim limitations as set forth above. Modified Yangzhou further discloses wherein j > 0, the InjGaAs base region is an InGaAs base region (Yangzhou - [0069]; j=1), and the InjGaAs emitter region is an InGaAs emitter region (Yangzhou - [0096]; j=1), w > 0, and the InwGaAsPz step barrier layer is an InGaAsP step barrier layer (Yangzhou – [0077] discloses GaAs or InGaAs; it is noted that the claim limitation does not preclude a value of z=0).
Modified Yangzhou does not explicitly disclose, in the MQW structure, k > 0, the InkGaAsPy barrier layer is an InGaAsP barrier layer.
Rohr discloses a multiple quantum well structure in a photovoltaic device (abstract) and further discloses the use of an InGaAsP barrier layer in the MQW structure ([0026] L32).
It would have been obvious to one of ordinary skill in the art at the time the invention was filed to form the MQW structure of modified Yangzhou with an InGaAsP barrier layer, as disclosed by Rohr, because as evidenced by Rohr, the use of an InGaAsP barrier layer in an MQW structure of a photovoltaic device amounts to the use of a known material in the art for its intended purpose to achieve an expected result, and one skilled in the art would have a reasonable expectation of success when forming the barrier layer of the MQW structure modified Yangzhou with InGaAsP based on the teaching of Rohr.
Regarding claim 5, modified Yangzhou discloses all the claim limitations as set forth above.
While modified Yangzhou does disclose w > 0 (Yangzhou – [0077] discloses GaAs or InGaAs) and k > 0 (Rohr - [0026] L32), and further discloses z < y (Yangzhou - ([0069],[0077],[0096]; y=1, z=0), modified Yangzhou does not explicitly disclose w = k.
Yangzhou discloses a high degree of lattice matching between the layers, the material of the potential well layer 231 in the multi-quantum well structure 23 may be InxGa1-xAs, the material of the barrier layer 233 may be GaAs1-yPy, wherein the value of x ranges from 0 to 0.3, and the value of y ranges from 0 to 0.5 ([0052]), and further discloses the buffer transition layer can effectively avoid uncontrolled stress relaxation and unclear interface between the strain potential well layer and the strain potential barrier layer when they are directly connected, and that this allows for more precise stress balance, reduces defects, and improves the problem of atomic interdiffusion at the interface between the potential well layer and potential barrier layer in a multi-quantum well structure ([0035]). As the material cost and the degree of stress balance are variables that can be modified, among others, by adjusting said values of k and w in the barrier layer and step barrier layer, respectively, the precise values of k and w would have been considered result effective variables by one having ordinary skill in the art at the time the invention was made. As such, without showing unexpected results, the claimed relationship between k and w cannot be considered critical. Accordingly, one of ordinary skill in the art at the time the invention was made would have optimized, by routine experimentation, the relationship between k and w in the barrier and step barrier layers of modified Yangzhou to obtain the desired balance between the material cost and the degree of stress balance (operation efficiency) (In re Boesch, 617 F.2d. 272, 205 USPQ 215 (CCPA 1980)), since it has been held that where the general conditions of the claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. (In re Aller, 105 USPQ 223).
Claims 8 and 9 are rejected under 35 U.S.C. 103 as being unpatentable over Yangzhou Changelight Co., Ltd. (CN 107546287 A, cited on 06/27/2025 IDS, hereinafter referred to Yangzhou, see attached machine translation) in view of Yan et al. (CN 218677183, see attached machine translation), as evidenced by Rohr et al. (US 2003/0089392), as applied to claim 1 above, and further in view of Cornfeld (US 2009/0272438).
Regarding claim 8, modified Yangzhou discloses all the claim limitations as set forth above. Modified Yangzhou further discloses the InGaAs subcell further comprises a back surface field layer disposed on a side of the InjGaAs base region opposite the InjGaAs emitter region (Yangzhou – [0068], back field layer 21), wherein the BSF layer is a GaInP layer (Yangzhou – [0068]).
Modified Yangzhou does not explicitly disclose the BSF layer is doped with the first conductivity type.
Cornfeld discloses a multijunction solar cell structure ([0025]) and further discloses the BSF layer is doped with a first conductivity type ([0066],[0067]).
It would have been obvious to one of ordinary skill in the art at the time the invention was filed to dope the BSF layer of modified Yangzhou with the first conductivity type, as disclosed by Cornfeld, because as taught by Cornfeld, the BSF layer drives minority carriers from the region near the base/BSF interface surface to minimize the effect of recombination loss ([0067]).
Regarding claim 9, modified Yangzhou discloses all the claim limitations as set forth above. Modified Yangzhou further discloses the InGaAs subcell further comprises: a window layer disposed on a side of the InjGaAs emitter region opposite the InjGaAs base region (Yangzhou – [0098]), wherein the window layer is a AlGaInP layer or AlInP layer (Yangzhou - [0098]).
Modified Yangzhou does not explicitly disclose the window layer is doped with the second conductivity type.
Cornfeld discloses a multijunction solar cell structure ([0025]) and further discloses an AlInP window layer doped with a second conductivity type ([0069]).
It would have been obvious to one of ordinary skill in the art at the time the invention was filed to dope the AlInP window layer of modified Yangzhou with the second conductivity type, as disclosed by Cornfeld, because as taught by Cornfeld, the window layer operates to reduce the interface recombination loss ([0069]).
Claims 12, 16-17, and 19-20 are rejected under 35 U.S.C. 103 as being unpatentable over Yangzhou Changelight Co., Ltd. (CN 107546287 A, cited on 06/27/2025 IDS, hereinafter referred to Yangzhou, see attached machine translation) in view of Yan et al. (CN 218677183, see attached machine translation).
Regarding claim 12, Yangzhou discloses a multijunction solar cell structure ([0046]) comprising a substrate ([0056] discloses a Ge substrate; [0064]) and a plurality of subcells stacked on the substrate ([0057]), wherein the plurality of subcells comprise an InGaAs subcell ([0069],[0096]), wherein the InGaAs subcell comprises an InjGaAs base region ([0069]; j=1) and an InjGaAs emitter region ([0096]; j=1) disposed in a direction away from the substrate ([0096],[0097]), and a multiple quantum well (MQW) structure disposed between the InjGaAs base region and the InjGaAs emitter region ([0070]), wherein the InjGaAs base region is doped with a first conductivity type ([0069]) and the InjGaAs emitter region is doped with a second conductivity type ([0096]), wherein the MQW structure comprises alternately stacked InxGaAs quantum well layers and InkGaAsPy barrier layers ([0077]; x=1, k=0, y=1), and an InwGaAsPz step barrier layer disposed between an InxGaAs quantum well layer and an InkGaAsPy barrier layer ([0077] discloses a buffer transition layer; w=0, z=0), and wherein a lattice constant of the InwGaAsPz step barrier layer is between a lattice constant of the InxGaAs quantum well layer and a lattice constant of the InkGaAsPy barrier layer ([0048];[0053];[0057]), and wherein j, x, y, k, w, and z are numbers greater than or equal to zero ([0069],[0077],[0096]; j=1, x=1, y=1, k=0, w=0, z=0).
While Yangzhou does disclose a high degree of lattice matching between the layers, the material of the potential well layer 231 in the multi-quantum well structure 23 may be InxGa1-xAs, the material of the barrier layer 233 may be GaAs1-yPy, wherein the value of x ranges from 0 to 0.3, and the value of y ranges from 0 to 0.5 ([0052]), and further discloses the buffer transition layer can effectively avoid uncontrolled stress relaxation and unclear interface between the strain potential well layer and the strain potential barrier layer when they are directly connected, and that this allows for more precise stress balance, reduces defects, and improves the problem of atomic interdiffusion at the interface between the potential well layer and potential barrier layer in a multi-quantum well structure ([0035]); Yangzhou does not explicitly disclose a lattice constant of the InwGaAsPz step barrier layer is between a lattice constant of the InxGaAs quantum well layer and a lattice constant of the InkGaAsPy barrier layer.
Yan discloses a multiple quantum well structure used in optoelectronic devices ([n0001],[n0003]) and further discloses a lattice constant of a step barrier layer is between a lattice constant of a quantum well layer and a lattice constant of a barrier layer ([n0005]).
It would have been obvious to one of ordinary skill in the art at the time the invention was filed to form the buffer transition layer of Yangzhou with a lattice constant between a lattice constant of the quantum well layer and a lattice constant of the barrier layer, as disclosed by Yan, because as taught by Yan, internal stress of the multi-quantum well structure is reduced and recombination efficiency of charge carriers is improved ([n0005]).
Regarding claim 16, modified Yangzhou discloses all the claim limitations as set forth above. Modified Yangzhou further discloses a thickness of the InxGaAs quantum well layer is 1 nm to 10 nm (Yangzhou – [0077]), a thickness of the InkGaAsPy barrier layer is 1 to 20 nm (Yangzhou – [0077]), and a thickness of the step barrier layer InwGaAsPz is 0.3 – 3 nm (Yangzhou – [0077]). It would have been obvious to one of ordinary skill in the art at the time of invention to have selected the overlapping portion of the ranges disclosed by the reference because selection of overlapping portion of ranges has been held to be a prima facie case of obviousness. In re Malagari, 182 USPQ 549.
Regarding claim 17, modified Yangzhou discloses all the claim limitations as set forth above. Modified Yangzhou further discloses x ranges from 0 to 0.3, and y ranges from 0 to 0.5 (Yangzhou – [0077]). It would have been obvious to one of ordinary skill in the art at the time of invention to have selected the overlapping portion of the ranges disclosed by the reference because selection of overlapping portion of ranges has been held to be a prima facie case of obviousness. In re Malagari, 182 USPQ 549.
Regarding claim 19, modified Yangzhou discloses all the claim limitations as set forth above. Modified Yangzhou further discloses the plurality of subcells comprise a first subcell, a second subcell, and a third sub cell arranged in a direction away from the substrate (Yangzhou – [0012],[0023]), wherein the first subcell is a Ge subcell (Yangzhou – [0014]), the second subcell is the InGaAs subcell (Yangzhou – [0014]), and the third subcell is an (Al)GaInP subcell (Yangzhou – [0014]), and wherein a first tunnel junction is disposed between the first subcell and the second subcell (Yangzhou – [0012]), and a second tunnel junction is disposed between the second subcell and the third subcell (Yangzhou – [0012]).
Regarding claim 20, modified Yangzhou discloses all the claim limitations as set forth above. Modified Yangzhou further discloses the first conductivity type is p-type (Yangzhou – [0069]), and the second conductivity type is n-type (Yangzhou – [0096]).
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Yangzhou Changelight Co., Ltd. (CN 107546287 A, cited on 06/27/2025 IDS, hereinafter referred to Yangzhou, see attached machine translation) in view of Yan et al. (CN 218677183, see attached machine translation) as applied to claim 12 above, and further in view of Chiou et al. (US 2007/0151595).
Regarding claim 13, modified Yangzhou discloses all the claim limitations as set forth above.
While modified Yangzhou does disclose, in the MQW structure, k=0, the InkGaAsPy barrier layer is a GaAsP barrier layer (Yangzhou - [0077]; k=0, y=1), w=0 (Yangzhou - [0077] discloses a buffer transition layer; w=0, z=0), and the InwGaAsPz step barrier layer is a GaAsP step barrier layer (Yangzhou - [0077] discloses a buffer transition layer; w=0, z=0), wherein z < y (Yangzhou - [0069],[0077],[0096]; j=1, x=1, y=1, k=0, w=0, z=0); modified Yangzhou does not explicitly disclose j=0, the InjGaAs base region is a GaAs base region, and the InjGaAs emitter region is a GaAs emitter region.
Chiou discloses a multijunction solar cell structure ([0016],[0025]) and further discloses a GaAs base region and a GaAs emitter region ([0025]).
It would have been obvious to one of ordinary skill in the art at the time the invention was filed to form the base and emitter regions of modified Yangzhou with GaAs, as disclosed by Chiou, because as evidenced by Chiou, the use of GaAs to form the base and emitter regions of a subcell of a multijunction solar cell structure amounts to the use of a known material in the art for its intended purpose to achieve an expected result, and one skilled in the art would have a reasonable expectation of success when forming the base and emitter regions of modified Yangzhou with GaAs based on the teaching of Chiou.
Claims 14 and 15 are rejected under 35 U.S.C. 103 as being unpatentable over Yangzhou Changelight Co., Ltd. (CN 107546287 A, cited on 06/27/2025 IDS, hereinafter referred to Yangzhou, see attached machine translation) in view of Yan et al. (CN 218677183, see attached machine translation) as applied to claim 12 above, and further in view of Rohr et al. (US 2003/0089392).
Regarding claim 14, modified Yangzhou discloses all the claim limitations as set forth above. Modified Yangzhou further discloses wherein j > 0, the InjGaAs base region is an InGaAs base region (Yangzhou - [0069]; j=1), and the InjGaAs emitter region is an InGaAs emitter region (Yangzhou - [0096]; j=1), w > 0, and the InwGaAsPz step barrier layer is an InGaAsP step barrier layer (Yangzhou – [0077] discloses GaAs or InGaAs; it is noted that the claim limitation does not preclude a value of z=0).
Modified Yangzhou does not explicitly disclose, in the MQW structure, k > 0, the InkGaAsPy barrier layer is an InGaAsP barrier layer.
Rohr discloses a multiple quantum well structure in a photovoltaic device (abstract) and further discloses the use of an InGaAsP barrier layer in the MQW structure ([0026] L32).
It would have been obvious to one of ordinary skill in the art at the time the invention was filed to form the MQW structure of modified Yangzhou with an InGaAsP barrier layer, as disclosed by Rohr, because as evidenced by Rohr, the use of an InGaAsP barrier layer in an MQW structure of a photovoltaic device amounts to the use of a known material in the art for its intended purpose to achieve an expected result, and one skilled in the art would have a reasonable expectation of success when forming the barrier layer of the MQW structure modified Yangzhou with InGaAsP based on the teaching of Rohr.
Regarding claim 15, modified Yangzhou discloses all the claim limitations as set forth above.
While modified Yangzhou does disclose w > 0 (Yangzhou – [0077] discloses GaAs or InGaAs) and k > 0 (Rohr - [0026] L32), and further discloses z < y (Yangzhou - ([0069],[0077],[0096]; y=1, z=0), modified Yangzhou does not explicitly disclose w = k.
Yangzhou discloses a high degree of lattice matching between the layers, the material of the potential well layer 231 in the multi-quantum well structure 23 may be InxGa1-xAs, the material of the barrier layer 233 may be GaAs1-yPy, wherein the value of x ranges from 0 to 0.3, and the value of y ranges from 0 to 0.5 ([0052]), and further discloses the buffer transition layer can effectively avoid uncontrolled stress relaxation and unclear interface between the strain potential well layer and the strain potential barrier layer when they are directly connected, and that this allows for more precise stress balance, reduces defects, and improves the problem of atomic interdiffusion at the interface between the potential well layer and potential barrier layer in a multi-quantum well structure ([0035]). As the material cost and the degree of stress balance are variables that can be modified, among others, by adjusting said values of k and w in the barrier layer and step barrier layer, respectively, the precise values of k and w would have been considered result effective variables by one having ordinary skill in the art at the time the invention was made. As such, without showing unexpected results, the claimed relationship between k and w cannot be considered critical. Accordingly, one of ordinary skill in the art at the time the invention was made would have optimized, by routine experimentation, the relationship between k and w in the barrier and step barrier layers of modified Yangzhou to obtain the desired balance between the material cost and the degree of stress balance (operation efficiency) (In re Boesch, 617 F.2d. 272, 205 USPQ 215 (CCPA 1980)), since it has been held that where the general conditions of the claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. (In re Aller, 105 USPQ 223).
Claim 18 is rejected under 35 U.S.C. 103 as being unpatentable over Yangzhou Changelight Co., Ltd. (CN 107546287 A, cited on 06/27/2025 IDS, hereinafter referred to Yangzhou, see attached machine translation) in view of Yan et al. (CN 218677183, see attached machine translation) as applied to claim 12 above, and further in view of Cornfeld (US 2009/0272438).
Regarding claim 18, modified Yangzhou discloses all the claim limitations as set forth above. Modified Yangzhou further discloses the InGaAs subcell further comprises a back surface field layer disposed on a side of the InjGaAs base region opposite the InjGaAs emitter region (Yangzhou – [0068], back field layer 21), wherein the BSF layer is a GaInP layer (Yangzhou – [0068]).
Modified Yangzhou does not explicitly disclose the BSF layer is doped with the first conductivity type.
Cornfeld discloses a multijunction solar cell structure ([0025]) and further discloses the BSF layer is doped with a first conductivity type ([0066],[0067]).
It would have been obvious to one of ordinary skill in the art at the time the invention was filed to dope the BSF layer of modified Yangzhou with the first conductivity type, as disclosed by Cornfeld, because as taught by Cornfeld, the BSF layer drives minority carriers from the region near the base/BSF interface surface to minimize the effect of recombination loss ([0067]).
Response to Arguments
Applicant's arguments filed 08/07/2026 have been fully considered but they are not persuasive. Specifically, Applicant argues that Yan does not disclose or suggest a multiple quantum well structure including InGaAs quantum well layers and InGaAsP barrier layers, nor discloses or suggests a InwGaAsPz step barrier layer having a bandgap lying between a quantum well layer and a barrier layer, let alone the required bandgap feature of the claimed InwGaAsPz step barrier layer.
In response to Applicant’s argument, the teachings of Yan are not relied upon alone to teach a multiple quantum well structure including InGaAs quantum well layers and InGaAsP barrier layers, nor a InwGaAsPz step barrier layer having a bandgap lying between a quantum well layer and a barrier layer, nor the required bandgap feature of the claimed InwGaAsPz step barrier layer; instead Yan is relied upon for its teaching of a multiple quantum well structure used in optoelectronic devices ([n0001],[n0003]) and a lattice constant of a step barrier layer lies between a lattice constant of a quantum well layer and a lattice constant of a barrier layer ([n0005]). As set forth in the office action, Yangzhou is relied upon to teach a multiple quantum well structure including InGaAs quantum well layers and InGaAsP barrier layers ([0069],[0077],[0096]), and an InwGaAsPz step barrier layer disposed between an InxGaAs quantum well layer and an InkGaAsPy barrier layer ([0077] discloses a buffer transition layer; w=0, z=0).
With regard to the limitation requiring a InwGaAsPz step barrier layer having a bandgap lying between a bandgap of the InxGaAs quantum well layer and a bandgap of the InkGaAsPy barrier layer, the limitation is satisfied because, as evidenced by Rohr, there is a linear relationship between bandgap values and lattice constants in InGaAsP compounds (Fig. 7), and therefore, one skilled in the art would expect a bandgap of the InwGaAsPz step barrier layer of modified Yangzhou to lie between a bandgap of the InxGaAs quantum well layer and a bandgap of the InkGaAsPy barrier layer (Yan - [n0005] discloses a lattice constant of a step barrier layer lies between a lattice constant of a quantum well layer and the lattice constant of a barrier layer as set forth above).
As set forth in the office action, Yangzhou discloses a high degree of lattice matching between the layers, the material of the potential well layer 231 in the multi-quantum well structure 23 may be InxGa1-xAs, the material of the barrier layer 233 may be GaAs1-yPy, wherein the value of x ranges from 0 to 0.3, and the value of y ranges from 0 to 0.5 ([0052]), and further discloses the buffer transition layer can effectively avoid uncontrolled stress relaxation and unclear interface between the strain potential well layer and the strain potential barrier layer when they are directly connected, and that this allows for more precise stress balance, reduces defects, and improves the problem of atomic interdiffusion at the interface between the potential well layer and potential barrier layer in a multi-quantum well structure ([0035]). It would have been obvious to one of ordinary skill in the art at the time the invention was filed to form the buffer transition layer of Yangzhou with a lattice constant lying between a lattice constant of the quantum well layer and a lattice constant of the barrier layer, as disclosed by Yan, because as taught by Yan, internal stress of the multi-quantum well structure is reduced and recombination efficiency of charge carriers is improved ([n0005]).
Therefore, with regard to Applicant’s argument that Yan does not disclose or suggest a multiple quantum well structure including InGaAs quantum well layers and InGaAsP barrier layers, nor discloses or suggests a InwGaAsPz step barrier layer having a bandgap lying between a quantum well layer and a barrier layer, let alone the required bandgap feature of the claimed InwGaAsPz step barrier layer; 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).
Applicant argues that Yan simply discloses adjusting lattice constants in a nitride-based LED structure using MgNx and SiNy stress modulation layers, and that Yan is directed to a fundamentally different material system from the claimed MQW structure. Applicant further argues that Yan relates to nitride-based light-emitting diodes (LEDs) formed from GaN and InGaN, not to the claimed InGaAs/InGaAsP material system of the claimed MQW structure.
In response to Applicant’s argument, Yan teaches a multiple quantum well structure used in optoelectronic devices ([n0001],[n0003]) and a lattice constant of a step barrier layer lies between a lattice constant of a quantum well layer and a lattice constant of a barrier layer ([n0005]).
The test for obviousness is not whether the features of a secondary reference may be bodily incorporated into the structure of the primary reference; nor is it that the claimed invention must be expressly suggested in any one or all of the references. Rather, the test is what the combined teachings of the references would have suggested to those of ordinary skill in the art. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981).
As set forth in the office action, Yangzhou does disclose a high degree of lattice matching between the layers, the material of the potential well layer 231 in the multi-quantum well structure 23 may be InxGa1-xAs, the material of the barrier layer 233 may be GaAs1-yPy, wherein the value of x ranges from 0 to 0.3, and the value of y ranges from 0 to 0.5 ([0052]), and further discloses the buffer transition layer can effectively avoid uncontrolled stress relaxation and unclear interface between the strain potential well layer and the strain potential barrier layer when they are directly connected, and that this allows for more precise stress balance, reduces defects, and improves the problem of atomic interdiffusion at the interface between the potential well layer and potential barrier layer in a multi-quantum well structure ([0035]).
It would have been obvious to one of ordinary skill in the art at the time the invention was filed to form the buffer transition layer of Yangzhou with a lattice constant lying between a lattice constant of the quantum well layer and a lattice constant of the barrier layer, as disclosed by Yan, because as taught by Yan, internal stress of the multi-quantum well structure is reduced and recombination efficiency of charge carriers is improved ([n0005]).
With regard to the limitation “a bandgap of the InwGaAsPz step barrier layer lies between a bandgap of the InxGaAs quantum well layer and a bandgap of the InkGaAsPy barrier layer,” as evidenced by Rohr, there is a linear relationship between bandgap values and lattice constants in InGaAsP compounds (Fig. 7), and therefore, one skilled in the art would expect a bandgap of the InwGaAsPz step barrier layer of modified Yangzhou to lie between a bandgap of the InxGaAs quantum well layer and a bandgap of the InkGaAsPy barrier layer (Yan - [n0005] discloses a lattice constant of a step barrier layer lies between a lattice constant of a quantum well layer and the lattice constant of a barrier layer as set forth above).
Applicant argues Yan’s MgNx/SiNy stress modulation layers are formed by partial substitution of Ga atoms with Mg or Si atoms within the GaN matrix, and that this substitution-based mechanism cannot be implemented as a separately formed layer in the nitride system without causing substantial lattice mismatch and consequent degradation of crystal quality. Applicant argues that in the claimed MQW structure, the InxGaAs quantum well layers, the InkGasPy barrier layers, and the InwGaAsPz step barrier layer are formed as a distinct, separately grown layers within the MQW structure and can be realized with high crystalline quality.
In response to Applicant’s argument, as set forth in the office action, Yangzhou discloses the buffer transition layer can effectively avoid uncontrolled stress relaxation and unclear interface between the strain potential well layer and the strain potential barrier layer when they are directly connected, and that this allows for more precise stress balance, reduces defects, and improves the problem of atomic interdiffusion at the interface between the potential well layer and potential barrier layer in a multi-quantum well structure ([0035]); and Yan discloses a multiple quantum well structure used in optoelectronic devices ([n0001],[n0003]) and further discloses a lattice constant of a step barrier layer lies between a lattice constant of a quantum well layer and a lattice constant of a barrier layer ([n0005]). It would have been obvious to one of ordinary skill in the art at the time the invention was filed to form the buffer transition layer of Yangzhou with a lattice constant lying between a lattice constant of the quantum well layer and a lattice constant of the barrier layer, as disclosed by Yan, because as taught by Yan, internal stress of the multi-quantum well structure is reduced and recombination efficiency of charge carriers is improved ([n0005]).
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).
Additionally, in response to Applicant's argument that one of ordinary skill in the art would not be motivated to transplant Yan’s nitride-specific substitution-based approach to the quaternary InGaAsP system of the present invention, and thus, the claimed MQW structure is directed to a different structure from Yan’s MgNx/SiNy stress modulation layers, the test for obviousness is not whether the features of a secondary reference may be bodily incorporated into the structure of the primary reference; nor is it that the claimed invention must be expressly suggested in any one or all of the references. Rather, the test is what the combined teachings of the references would have suggested to those of ordinary skill in the art. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981).
Applicant argues that Yan simply discloses that the MgNx and SiNy modifications serve as stress modulation layers for strain management in LED structures, and that the claimed InwGaAsPz step barrier layer provides multiple technical benefits, and that the claimed InGaAsP step barrier layer’s bandgap is set to lie between the bandgap of the quantum well layer and the bandgap of the barrier layer, which lowers the barrier height and facilitates photogenerated carriers to more easily overcome the barrier, thereby improving carrier transport, enhancing photoelectric conversion efficiency, and increasing both the open-circuit voltage and the fill factor of the multijunction solar cell, and moreover, the interface between the InwGaAsPz step barrier layer and the InxGaAs quantum well layer significantly reduces atomic interdiffusion compared to the original interface between the InkGaAsPy barrier layer and the InxGaAs quantum well layer, yielding a smoother AsP interface and thus enhancing light absorption of the MQW structure. Applicant argues that Yan or Yangzhou does not disclose how to achieve such technical benefits of amended claim 1.
In response to Applicant’s argument, claim 1 recites “wherein j, x, y, k, w, z are numbers greater than or equal to 0” in conjunction with the other limitations recited in claim 1, however, evidence has not been provided, commensurate in scope with the breadth of the limitations of claim 1, of the multiple technical benefits described in Applicant’s arguments above.
It is also well settled that where patentability is predicated upon a change in a condition of a prior art composition, such as a change in size, concentration or the like, the burden is on the applicant to establish with objective evidence that the change is critical, i.e., it leads to a new, unexpected result. In re Woodruff 919 F.2d 1575, 1578 (Fed. Cir. 1990); In re Aller, 220 F.2d 454, 456 (CCPA 1955).
In response to Applicant’s arguments, unexpected results must be established by factual evidence; mere argument or conclusory statements in the specification do not suffice. In re Geisler, 116 F.3d 1465, 1470, 43 USPQ2d 1362, 1365 (Fed. Cir. 1977) (quoting In re De Blauwe, 736 F.2d 699, 705, 222 USPQ 191, 196 (Fed. Cir. 1984)). Applicant’s argument is not persuasive because Applicant’s assertions of unexpected results constitute mere argument (MPEP 716.01(c)). Unexpected results must be established by factual evidence (MPEP 716.01(c)). Mere conclusions in the as-filed specification and Applicant’s Remarks, without evidence in support of the assertions, are insufficient in showing the criticality of the claimed range. MPEP 716.02(d) II. states “To establish unexpected results over a claimed range, applicants should compare a sufficient number of tests both inside and outside of the claimed range to show the criticality of the claimed range. In re Hill, 284 F.2d 955, 128 USPQ 197 (CCPA 1960).” It is also well settled that where patentability is predicated upon a change in a condition of a prior art composition, such as a change in size, concentration or the like, the burden is on the applicant to establish with objective evidence that the change is critical, i.e., it leads to a new, unexpected result. In re Woodruff 919 F.2d 1575, 1578 (Fed. Cir. 1990); In re Aller, 220 F.2d 454, 456 (CCPA 1955).
As set forth in MPEP 716.02(d): Whether the unexpected results are the result of unexpectedly improved results or a property not taught by the prior art, the "objective evidence of nonobviousness must be commensurate in scope with the claims which the evidence is offered to support." In other words, the showing of unexpected results must be reviewed to see if the results occur over the entire claimed range. In re Clemens, 622 F.2d 1029, 1036, 206 USPQ 289, 296 (CCPA 1980).
Additionally, in response to Applicant's argument that the claimed InwGaAsPz step barrier layer provides multiple technical benefits, the fact that the inventor has recognized another advantage which would flow naturally from following the suggestion of the prior art cannot be the basis for patentability when the differences would otherwise be obvious. See Ex parte Obiaya, 227 USPQ 58, 60 (Bd. Pat. App. & Inter. 1985).
As set forth in the office action, Yangzhou discloses the buffer transition layer can effectively avoid uncontrolled stress relaxation and unclear interface between the strain potential well layer and the strain potential barrier layer when they are directly connected, and that this allows for more precise stress balance, reduces defects, and improves the problem of atomic interdiffusion at the interface between the potential well layer and potential barrier layer in a multi-quantum well structure ([0035]); and Yan discloses a multiple quantum well structure used in optoelectronic devices ([n0001],[n0003]) and further discloses a lattice constant of a step barrier layer lies between a lattice constant of a quantum well layer and a lattice constant of a barrier layer ([n0005]). It would have been obvious to one of ordinary skill in the art at the time the invention was filed to form the buffer transition layer of Yangzhou with a lattice constant lying between a lattice constant of the quantum well layer and a lattice constant of the barrier layer, as disclosed by Yan, because as taught by Yan, internal stress of the multi-quantum well structure is reduced and recombination efficiency of charge carriers is improved ([n0005]).
Applicant argues that Rohr does not disclose or suggest a linear relationship between bandgap and lattice constant for a given composition. To the contrary, one of ordinary skill in the art understands that bandgap and lattice constant do not have a linear relationship in general, and certainly not one that would allow a prediction that any layer having an intermediate lattice constant necessarily possesses an intermediate bandgap. In the quaternary InGaAsP system, both In and P compositions independently affect bandgap and lattice constant, such that a layer with a lattice constant between two other layers may have a bandgap that is higher than, lower than, or between the bandgaps of those layers depending on the specific compositional choices. Applicant argues that Rohr cannot be combined with Yangzhou or Yan to supply the missing features, and it certainly does not disclose the claimed structure itself.
The position set forth in the office action is that one skilled in the art would expect, based on the teaching of Rohr that there is a linear relationship between bandgap values and lattice constants in InGaAsP compounds (Fig. 7), that a bandgap of the InwGaAsPz step barrier layer of modified Yangzhou to lie between a bandgap of the InxGaAs quantum well layer and a bandgap of the InkGaAsPy barrier layer (Yan - [n0005] discloses a lattice constant of a step barrier layer lies between a lattice constant of a quantum well layer and the lattice constant of a barrier layer as set forth above).
While Applicant argues that one of ordinary skill in the art understands that bandgap and lattice constant do not have a linear relationship in general, and certainly not one that would allow prediction that any layer having an intermediate lattice constant necessarily possesses an intermediate bandgap; Applicant does not provide evidence that the In and P compositions differ from the In and P composition of the material system InxGa1-xAs1-yPy of Figure 7 of Rohr in a manner that would lead one skilled in the art to not expect the disclosed relationship between bandgap and lattice constant. Absent evidence to the contrary, one skilled in the art would expect, based on the teaching of Rohr that there is a linear relationship between bandgap values and lattice constants in InGaAsP compounds in a InxGa1-xAs1-yPy material system (Fig. 7), that a bandgap of the InwGaAsPz step barrier layer of modified Yangzhou to lie between a bandgap of the InxGaAs quantum well layer and a bandgap of the InkGaAsPy barrier layer (Yan - [n0005] discloses a lattice constant of a step barrier layer lies between a lattice constant of a quantum well layer and the lattice constant of a barrier layer as set forth above).
With regard to Applicant’s argument that amended claim 1 further recites “a lattice constant of the InwGaAsPz step barrier layer is between a lattice constant of the InxGaAs quantum well layer and a lattice constant of the InkGaAsPy barrier layer,” as set forth in the office action, while Yangzhou does disclose a high degree of lattice matching between the layers, the material of the potential well layer 231 in the multi-quantum well structure 23 may be InxGa1-xAs, the material of the barrier layer 233 may be GaAs1-yPy, wherein the value of x ranges from 0 to 0.3, and the value of y ranges from 0 to 0.5 ([0052]), and further discloses the buffer transition layer can effectively avoid uncontrolled stress relaxation and unclear interface between the strain potential well layer and the strain potential barrier layer when they are directly connected, and that this allows for more precise stress balance, reduces defects, and improves the problem of atomic interdiffusion at the interface between the potential well layer and potential barrier layer in a multi-quantum well structure ([0035]); Yangzhou does not explicitly disclose a bandgap of the InwGaAsPz step barrier layer lies between a bandgap of the InxGaAs quantum well layer and a bandgap of the InkGaAsPy barrier layer.
Yan discloses a multiple quantum well structure used in optoelectronic devices ([n0001],[n0003]) and further discloses a lattice constant of a step barrier layer lies between a lattice constant of a quantum well layer and a lattice constant of a barrier layer ([n0005]).
It would have been obvious to one of ordinary skill in the art at the time the invention was filed to form the buffer transition layer of Yangzhou with a lattice constant lying between a lattice constant of the quantum well layer and a lattice constant of the barrier layer, as disclosed by Yan, because as taught by Yan, internal stress of the multi-quantum well structure is reduced and recombination efficiency of charge carriers is improved ([n0005]).
Based on the teachings cited in the office action, the claimed subject matter merely combines familiar elements according to known methods and does no more than yield predictable results. See MPEP 2143 |. A. and KSR v. Teleflex (Supreme Court 2007).
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.
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/TAMIR AYAD/Primary Examiner, Art Unit 1726
