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 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 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) 33-37, 43-46, and 49-55 is/are rejected under 35 U.S.C. 103 as being unpatentable over Snaith et al. (WO 2014/045021) in view of Choi et al. (“Cesium-doped methylammonium lead iodide perovskite light absorber for hybrid solar cells”) and in view of Jeon et al. (“Compositional engineering of perovskite materials for high-performance solar cells”).
Regarding claim 33, Snaith discloses a multi-junction photovoltaic device (see Figure 16) comprising:
a first sub-cell (perovskite absorber; see Figure 16) disposed over a second sub-cell (HIT; page 6),
wherein the first sub-cell comprises an n-type region comprising at least one n- type layer (n-type TiO2; see Figure 16),
a p-type region comprising at least one p-type layer (p-type HTM; see Figure 16), and
a photoactive region (perovskite absorber; see Figure 16) comprising a layer of perovskite material without open porosity that is disposed between the n-type region and the p-type region and that forms a planar heterojunction with one or both of the n-type region and the p-type region (second paragraph on page 2; see Figure 16);
wherein the perovskite material is FAxA’1-xPbI3-yBry (formula (II) ABX3-y X’y, where y is 0.05 to 2.95 on page 24; it is disclosed the organic cation can have a formula CH(NH2)2 (page 52) and the perovskite can comprise a formamidinium cation (page 79). it is further disclosed B is a metal cation, where the metal cation is preferably a divalent metal cation including Pb2+ (page 58), and it is disclosed X is two or more different anions (page 52), where the two different anions can be iodide and bromide (page 59)); and
wherein the second sub-cell comprises a silicon heterojunction (SHJ) (HIT cell as seen in Figure 16), and that alternatively, A may be an inorganic monovalent cation such as Cs+ (page 60), but the reference does not expressly disclose the perovskite material comprises an organic cation such as FA+ and a monovalent inorganic cation such as Cs+.
Choi discloses a perovskite absorber for solar cells comprising an organolead halide perovskite composition such as cesium-doping in methylammonium lead iodide (abstract), such that cesium partially replaces the organic cation in the perovskite formula (third paragraph on page 81) without fundamentally changing the crystal structure due to its similar size to the MA cation (second paragraph on page 82). Choi further discloses the increase in the amount of Cs incorporated increased absorption in the range of 300-400 nm but decreased absorption in the range of 450 nm-800 nm and band gap increased with the increase of Cs content (third paragraph on page 82) as well as the morphology of the film (second paragraph on page 84; see Figure 4), where short circuit current density and open circuit voltage, and thus the conversion efficiency, all improved compared to a perovskite material without the incorporation of Cs with an optimal amount of Cs content (see Table 1).
Jeon discloses it is well known in the art before the effective filing date of the claimed invention that methylammonium cations and formamidinium cations in an inorganic-organic lead halide perovskite material for solar cells exhibit slightly different properties such that FAPbI3 has a lower band gap than MAPbI3 due to the slightly larger ionic radius of FA compared to MA (1.9-2.2 Å vs 1.8 Å) and FA has an absorption edge of 840 nm compared to the absorption edge of MA of 800 nm, but the lower bandgap allows absorption of photons over a broader solar spectrum (second and third paragraphs on page 476). Jeon further discloses while FAPbI3 has lower performance than MaPbI3, it can be improved by stabilizing the FAPbI3 phase, improving the crystallinity, and optimizing the cell architecture (third paragraph on page 476). As MA and Cs are known to have a similar ionic radius, as disclosed by Choi, and therefore similar results can be expected by one of ordinary skill in the art with the replacement of FA with Cs in the perovskite material of Snaith.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use a known technique to improve similar devices such as partially replacing the FA cation with Cs in the perovskite material of Snaith, as taught by Choi and Jeon above, so that the formamidinium based lead halide perovskite material of Snaith can be improved through the incorporation of cesium ions that would alter the perovskite structure, morphology of the material, and change in absorption range, as set forth above. It is noted that if a technique is known to improve a device and one of ordinary skill in the art recognizes it would improve similar devices in the same way, the use of the known technique to improve similar devices would be prima facie obvious as the results would have been predictable to one of ordinary skill in the art unless the actual application of the technique would have been beyond the skill of one of ordinary skill in the art. KSR, 550 U.S. at 417, 82 USPQ2d at 1396. It is further noted that the partial replacement of FA with Cs would result in x being between 0 and 1 as recited.
While modified Snaith discloses y can be between 0.05 to 2.95, as set forth above, the reference does not expressly disclose y is between 0 and 1.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed 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 Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990); In re Geisler, 116 F.3d 1465, 1469-71, 43 USPQ2d 1362, 1365-66 (Fed. Cir. 1997).
Regarding claim 34, modified Snaith discloses all the claim limitations as set forth above, and further discloses the photoactive region consists of the perovskite material (as set forth above).
Regarding claim 35, modified Snaith discloses all the claim limitations as set forth above, and further discloses the layer of perovskite material is disposed as a substantially continuous and conformal layer on a surface (surface of the compact TiO2) that conforms to the adjacent surface of the second sub-cell (pages 2 and 62; see Figure 16).
Regarding claim 36, modified Snaith discloses all the claim limitations as set forth above, and further discloses an intermediate region (tunnel junction) disposed between and connecting the first sub- cell and the second sub-cell (page 43), wherein the intermediate region comprises one or more interconnect layers (one or more tunnel junctions).
Regarding claim 37, modified Snaith discloses all the claim limitations as set forth above, and further discloses each of the one or more interconnect layers comprises a transparent conductor material (tunnel junction between two photoactive layers as set forth above).
Regarding claim 43, modified Snaith discloses all the claim limitations as set forth above, and further discloses the n-type region comprises an n-type layer that comprises an organic n-type material (it is disclosed n-type layer can be organic; page 29).
Regarding claim 44, modified Snaith discloses all the claim limitations as set forth above, and further discloses the organic n-type material is selected from any of a fullerene or a fullerene derivative, a perylene or a derivative thereof, or poly{[N,NO-bis(2-octyldodecyl)-naphthalene-1,4,5,8- bis(dicarboximide)-2,6-diyl]-alt-5,50-(2,20-bithiophene)} (P(ND12OD-T2)) (page 29).
Regarding claim 45, modified Snaith discloses all the claim limitations as set forth above, and further discloses the p-type region comprises a p-type layer that comprises an inorganic p-type material (page 31).
Regarding claim 46, modified Snaith discloses all the claim limitations as set forth above, and further discloses the inorganic p-type material is selected from any of:
an oxide of nickel, vanadium, copper or molybdenum; and
CuI, CuBr, CuSCN, Cu2O, CuO or CIS (page 31).
Regarding claim 49, modified Snaith discloses all the claim limitations as set forth above, and further discloses the n-type region is adjacent to the second sub-cell (see Figure 16).
Regarding claim 50, modified Snaith discloses all the claim limitations as set forth above, and further discloses a first electrode (TCO) and a second electrode (silver); and
wherein the first sub-cell and the second sub-cell are disposed between the first and second electrodes with the first sub-cell in contact with the first electrode (see Figure 16).
Regarding claim 51, modified Snaith discloses all the claim limitations as set forth above, and further discloses the first electrode is in contact with the p-type region of the first sub-cell (see Figure 16).
Regarding claim 52, modified Snaith discloses all the claim limitations as set forth above, and further discloses the first electrode comprises a transparent or semi-transparent electrically conductive material (TCO; page 36).
Regarding claim 53, modified Snaith discloses all the claim limitations as set forth above, and further discloses the first electrode consists of a layer of indium tin oxide (ITO) (page 36).
Regarding claims 54 and 55, modified Snaith discloses all the claim limitations as set forth above.
While modified Snaith does not expressly disclose the photoactive region of the first sub-cell comprises a layer of perovskite material having a band gap between 1.65 eV to 1.75 eV, Snaith further discloses the band gap of organometal halide perovskite semiconductors are about 1.5 eV to 1.6 eV (page 19) and Choi disclosed above the perovskite material band gap increases with the increase of Cs content.
Therefore, it is noted that modified Snaith discloses the incorporation of Cs in the perovskite material in the amount as recited in the claim, and therefore is the same as the claimed composition for the perovskite material, it will, inherently, display the recited property of having a band gap from 1.65 eV to 1.75 eV as claimed, where the incorporation of Cs in perovskite increases the band gap. See MPEP 2112.01 (I). Additionally, one of ordinary skill in the art would appreciate “about 1.6 eV” reads upon 1.65 eV as claimed. Case law holds that a prima facie case of obviousness exists where the claimed ranges and prior art ranges do not overlap but are close enough that one skilled in the art would have expected them to have the same properties. Titanium Metals Corp. of America v. Banner, 778 F.2d 775, 227 USPQ 773 (Fed. Cir. 1985).
Claims 38 and 39 is/are rejected under 35 U.S.C. 103 as being unpatentable over Snaith et al. (WO 2014/045021) (from 12/12/17 IDS) in view of Choi et al. (“Cesium-doped methylammonium lead iodide perovskite light absorber for hybrid solar cells”) in view of Jeon et al. (“Compositional engineering of perovskite materials for high-performance solar cells”) in view of Eickemeyer et al. (WO 2016/012274) and further in view of Filipic et al. (“CH3NH3PBI3 perovskite/silicon tandem solar cells: characterization based optical simulations”) (from 12/12/17 IDS).
Regarding claims 38 and 39, modified Snaith discloses all the claim limitations as set forth above, and discloses each of the one or more interconnect layers comprises a tunnel junction, as set forth above, but the reference does not expressly disclose the intermediate region comprises an interconnect layer that consists of indium tin oxide.
Eickemeyer discloses a multi-junction photovoltaic device comprising a first subcell comprising a perovskite material (40, 50, 60) and a second subcell comprising a silicon material (20 and 30) and an intermediate region (35) that is a charge recombination layer comprising an n-type metal oxide such as ITO and a highly p-doped silicon (also known as a tunnel junction) (page 3 lines 23-page 4 line 13).
Modified Snaith and Eickemeyer are analogous because both are directed to multi junction photovoltaic devices comprising a perovskite cell and a silicon cell.
As modified Snaith is not limited to any specific examples of the tunnel junction in between the two sub-cells and as a tunnel junction comprising an n-type metal oxide such as ITO and a highly p-doped silicon were well known in the art before the effective filing date of the claimed invention, as evidenced by Eickemeyer above, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have selected any suitable tunnel junction configuration, including one having an n-type metal oxide such as ITO and a highly p-doped silicon in the device of modified Snaith. Said combination would amount to nothing more than the use of a known element for its intended use in a known environment to accomplish an entirely expected result.
Modified Snaith does not disclose the layer of ITO has a thickness of from 10 nm to 60 nm.
Filipic discloses a multi-junction photovoltaic device (see two terminal device in Figure 1B) comprising a first subcell comprising a perovskite material (top sub-cell) and a second subcell comprising a heterojunction silicon material (bottom sub-cell) and an intermediate region (bottom ITO) comprising one or more interconnect layers, wherein each of the one or more interconnect layers comprises a transparent conductor material such as ITO having a thickness from 20 to 150 nm (see Table 1 and Figure 1B).
Modified Snaith and Filipic are analogous because both are directed to multi junction photovoltaic devices comprising a perovskite cell and a heterojunction silicon cell.
As modified Snaith is not limited to any specific examples of the thickness for the interconnect layer and as an interconnect layer consisting of ITO having a thickness between 20 and 150 nm was well known in the art before the effective filing date of the claimed invention, as evidenced by Filipic above, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have selected any suitable thickness for the ITO layer, including a thickness between 20 and 150 nm in the device of modified Snaith. Said combination would amount to nothing more than the use of a known element for its intended use in a known environment to accomplish an entirely expected result.
Further, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed 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 Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990); In re Geisler, 116 F.3d 1465, 1469-71, 43 USPQ2d 1362, 1365-66 (Fed. Cir. 1997).
Response to Arguments
Applicant's arguments filed 10/8/2025 have been fully considered but they are not persuasive.
Applicant argues that a reasonable expectation of success is not present for the modification of Snaith in view of Choi and in view of Jeon because the combination proposed by the Office could only be achieved through impermissible hindsight reconstruction derived from Applicant’s own teachings.
In response to applicant's argument that the examiner's conclusion of obviousness is based upon improper hindsight reasoning, it must be recognized that any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning. But so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and does not include knowledge gleaned only from the applicant's disclosure, such a reconstruction is proper. See In re McLaughlin, 443 F.2d 1392, 170 USPQ 209 (CCPA 1971).
However, no knowledge gleaned only from the applicant’s disclosure was used for the combination of the references. Applicant has not pointed out where the Office relied upon their own disclosure for the combination. In fact, the Office Action clearly outlines the reasonings for the modification on pages 4 and 5 of the prior Office Action.
Applicant argues that nowhere does Choi teach that adding Cs to MAPbI3 would necessarily improve its performance at any concentration or condition, such that the skilled person would readily observe from Choi’s manuscript (Table 1), that the addition of Cs to MAPbI3 can lead to a decreased performance with an increase in the Cs content, where the effects of Cs incorporation are complex and context-dependent and requires substantial technical nuance and careful compositional design to achieve any desired outcome.
However, Choi clearly states that the incorporation of Cs in perovskite material in MAPbI3 improves the conversion efficiency when compared to non-doped MAPbI3, and that Table 1 of Choi demonstrates a variety of amounts of Cs doping vs MAPbI3 and CsPBI3 where Cs fully replaces MA and for when no doping is made, such that it is unclear how the effects of Cs incorporation is complex and requires substantial technical nuance and careful compositional design when optimizing the amount of dopant to be incorporated into a composition is well-known by one of ordinary skill in the art.
Additionally, Applicant has not provided any evidence to show the incorporation of Cs in MAPbI3 is unpredictable and provides unexpected results at different amounts.
Applicant further argues that Choi’s disclosure states that Cs incorporation into MAPbI3 can be either beneficial or detrimental, depending on the specific conditions employed and that most of the disclosed Cs containing MAPbI3 samples exhibit lower power conversion efficiency than the unsubstituted material and therefore Cs addition does not inherently improve performance.
However, it can be seen in Table 1 of Choi that the amount of Cs substitution of MA is merely an optimizable component of the composition, such that Choi still teaches the incorporation of Cs in MAPbI3 to be beneficial and the amount is optimizable depending on the desired properties. The fact there are undesired amounts of Cs incorporation does not teach away from the fact there are desirable amounts of Cs incorporation or that the incorporation of any amount of Cs is undesirable. Applicant is suggested to further limit the claimed range of the amount of Cs substituted in the perovskite material to overcome the rejection.
Applicant further argues that the Office fails to define the term “optimal amount”, such that a skilled person would require considerable time and non-routine experimentation to find any composition that meets the requirements of the claimed invention.
However, it is unclear how determining the optimal amount would require considerable time and non-routine experimentation when one can easily make such experiments by substituting Cs in amounts with similar increments as Choi as presented in Table 1, which is merely nine samples, or even less samples if they wish. Applicant is encouraged to explain their definition of “considerable time” and “non-routine experimentation” in terms of the amount that is known by a skilled person in the art because it appears nine samples is unreasonable for the skilled person who is well-versed in research to carry out.
Applicant also argues that a skilled person in the art would not rely on the data in Table 1 of Choi because it relates to a perovskite containing MA. However, the modification of Snaith is a combination with the teachings of Choi and Jeon, such that Jeon was provided to explain why one of ordinary skill in the art would be motivated to make the modification based on the teaching of Choi.
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).
Applicant argues nowhere does Choi state Cs and MA are of similar size and the Office’s reasoning selectively interprets the prior art to align with the present invention without adequate evidentiary support. However, citation was provided in the Office Action, such that Choi stated in the second paragraph on page 82 that “[a]s shown in Figure 1a, the similar size of Cs and MA cations allows the Cs ions to substitute and coexist with MA ions in the cubo-octahedral ‘A’ sites of the octahedral unit cell without fundamentally changing the crystal structure.” It is unclear how Choi did not state such and the Office Action lacks evidentiary support as asserted.
Applicant further argues Figure 1a of Choi is merely a schematic, ball and stick representation of a perovskite crystal structure with no scale provided. However, Applicant has not provided any evidence that MA and Cs are not of “similar size”. In fact, in the parent application 17/884,367 this argument was discussed previously in the Final Office Action mailed on 8/4/2023, where Filip was cited to provide dimensions for the MA and Cs radii. Page 13 of the Final Office Action states that Filip states FA, MA, and Cs+ steric radii are calculated by using the radius of the sphere that contains 95% of the DFT electron density through the use of density functional theory, such that FA is 2.24 Å, MA is 2.03 Å, and Cs+ is 1.77 Å, where the ionic radius for Cs+ is 1.88 Å (Supplementary Table 1). The application was subsequently abandoned, so no response from Applicant was filed in response to the arguments made in the Final Office Action mailed on 8/4/2023.
Applicant goes on to argue that Cs addition is complex and unpredictable, and that Choi neither establishes that Cs and MA are of a similar size. However, as set forth above, none of these statements made by Applicant is supported by any evidence and is merely conclusory statements without any factual basis.
Applicant also argues that mixing MA and FA would lead to deterioration in device properties. However, nowhere does the Office propose mixing MA and FA in the Office Action. Additionally, many of these arguments have already been responded to in the Final Office Action of 17/884,367 mailed on 8/4/2023, including the repeated arguments that the art is unpredictable and there is no reasonable expectation of success.
Therefore, the arguments were not found to be persuasive.
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 CHRISTINA CHERN whose telephone number is (408)918-7559. The examiner can normally be reached Monday-Friday, 9:30 AM-5:30 PM PT.
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/CHRISTINA CHERN/Primary Examiner, Art Unit 1722