DETAILED ACTION
This is the first Office Action regarding application number 18/841,928, filed on 08/27/2024, which is a 371 of PCT/US2314/110, filed on 02/28/2023, which is a continuation of PRO 63/314,809, filed on 02/28/2022.
This action is in response to the Applicant’s Response received 12/29/2025.
Election of Restricted Inventions
The Applicant’s election without traverse of Group II, Species A4 (claims 15-20, 22, and 24-26) is acknowledged.
Status of Claims
Claims 1, 3-10, 14-20, 22, and 24-26 are currently pending.
Claims 2, 11, 13, 21, 23, and 27-77 are canceled.
Claims 6, 7, and 20 are amended.
Claims 1, 3-10, and 14 are withdrawn.
Claims 15-20, 22, and 24-26 are examined below.
No claim is allowed.
Claim Objections
Claims 19 and 20 are objected to because of the following informalities:
Claim 19 recites “wherein the ICE layer comprises sulfur” but claim 15 already recites that “the ICE layer comprises sulfur”. The applicant should amend claim 19 to remove the redundancy.
Claim 20 should use commas instead of semi-colons for the list of compounds for the ICE layer.
Appropriate correction is required.
Claim Rejections - 35 USC § 112
Indefiniteness
The following is a quotation of 35 U.S.C. 112(b):
(B) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
Claims 15-20, 22, and 24-26 are rejected under 35 U.S.C. 112 as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor, or for pre-AIA the applicant regards as the invention.
Claim 15 recites “A method of making a photovoltaic device”, but then proceeds to recite only providing an absorber layer, an improved carrier extraction layer, and a p-type contact layer. These three layers cannot by themselves function to make a photovoltaic device. There must be at least one other electrode, and at least one other layer of an n-type doping in order to form the photoelectric junction. All depending claims are similarly rejected as they incorporate by reference all of the indefiniteness issues as the parent claim 15.
Claim 15 also recites “an absorber layer stack” but only describe this “stack” as having a single absorber layer. The examiner cannot understand how a single layer forms a “stack”, as this word is conventionally used.
Claim 15 also recites “a second surface” but not “a first surface”. This renders the claim unclear.
Claim 16 recites “tunable by selection of thiol compound”, but it is not at all clear or certain that claim 16’s “thiol compound” refers back to claim 15’s “deprotonated thiol compound”.
Claim 19 recites “a comparable device lacking an ICE layer”. This is unclear because what does “comparable” mean? Must the device be exactly identical but for the ICE layer? Claim 19 also recites “lacking an ICE layer” and does not use proper antecedent basis. The examiner cannot determine if the “ICE layer” of the comparable device must possess the identical composition as the ICE layer recited in claims 15/19.
Claim Rejections - 35 USC § 103
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 of this title, 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 set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied 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 15-20, 22, and 24-26 are rejected under 35 U.S.C. 103 as being unpatentable over REDDY (US 2008/0230120 A1) in view of CHRISTENSEN (US 2014/0273407 A1) and JASIENIAK (US 2013/0280854 A1).
Regarding claim 15, REDDY teaches a method of making a photovoltaic device comprising:
providing an absorber layer stack having an absorber layer comprising cadmium (Cd); and forming a p-type contact layer over the ICE layer (see CdTe absorber layer 1160 and p-type contact layer 1170, Fig. 11 and para. 92).
REDDY does not disclose expressly passivating a surface region of the absorber layer to form a passivated surface at a second surface of the absorber layer;
forming an improved carrier extraction (ICE) layer over the passivated surface, wherein: the ICE layer contacts the second surface of the absorber layer, and
the ICE layer comprises sulfur in a deprotonated thiol compound.
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CHRISTENSEN teaches that a CdTe absorber layer should be passivated using a chemical such as NaOH or KOH (para. 40) in order to improve the overall solar cell manufacturing process robustness and the panel manufacturing yield (para. 130).
Skilled artisans would have found it obvious to modify REDDY and passivate the CdTe absorber layer using a chemical such as NaOH or KOH (para. 40) in order to improve the overall solar cell manufacturing process robustness and the panel manufacturing yield as taught by CHRISTENSEN.
JASIENIAK teaches a method for the production of an inorganic CdTe absorber film, where sulfur-containing ligands such as 1,2-ethanedithiol (EDT) are attached to induce stronger electronic coupling between nanoparticles, and avoid grain growth (para. 230). 1,2-ethanedithiol attached to CdTe would naturally be deprotonated upon connection.
Skilled artisans would have found it obvious to modify REDDY and finally add sulfur-containing ligand molecules to a passivated CdTe surface (thus forming an ICE layer) to induce stronger electronic coupling between nanoparticles, and avoid grain growth as taught by JASIENIAK.
Regarding claim 16, modified REDDY teaches the method of claim 15, but does not disclose explicitly that a surface workfunction of the ICE layer on the absorber layer is tunable by selection of thiol compound over a 600 meV range as measured by Kelvin Probe measurements of surface workfunction. When the structure recited in the reference is substantially identical to that of the claims, claimed properties or functions are presumed to be inherent. It is well settled that where there is a reason to believe that a functional characteristic would be inherent in the prior art, the burden of proof then shifts to the applicant to provide objective evidence to the contrary. In re Schreiber, 128 F.3d at 1478, 44 USPQ2d at 1478, 44 USPQ2d at 1432 (Fed. Cir. 1997) (see MPEP 2112.01). Here, since modified REDDY uses all of the exact same chemical compositions as the applicant, skilled artisans would find it apparent that the surface workfunction of the ICE-absorber layer interface would also possess the tunability property claimed here.
Since the examiner does not have proper means to conduct experiments, the burden of proof is now shifted to applicants to show otherwise. In re Best, 562 F.2d 1252, 195 USPQ 430 (CCPA 1977); In re Fitzgerald, 205 USPQ 594 (CCPA 1980).
Regarding claim 17, modified REDDY teaches the method of claim 15, wherein the passivating step comprises contacting the second surface of the absorber layer with an alkaline passivation agent (CHRISTENSEN teaches the KOH and NaOH alkaline passivation agent).
Regarding claim 18, modified REDDY teaches the method of claim 15, wherein the absorber layer comprises tellurium and wherein a ratio of Cd to Te in the surface region of the absorber layer is within a range from 1:1 to 4:1 (REDDY teaches CdTe which is a 1:1 ratio)
Regarding claim 19, modified REDDY teaches the method of claim 15, wherein the ICE layer comprises sulfur, and wherein the sulfur forms a complex with Cd at the passivated surface (EDT would bond thru the sulfur to the Cd atoms as required by physics), but does not disclose expressly that the ICE layer produces a photoluminescence intensity enhancement of 2-10 times the photoluminescence intensity as compared to a comparable device lacking an ICE layer. When the structure recited in the reference is substantially identical to that of the claims, claimed properties or functions are presumed to be inherent. It is well settled that where there is a reason to believe that a functional characteristic would be inherent in the prior art, the burden of proof then shifts to the applicant to provide objective evidence to the contrary. In re Schreiber, 128 F.3d at 1478, 44 USPQ2d at 1478, 44 USPQ2d at 1432 (Fed. Cir. 1997) (see MPEP 2112.01). Here, since modified REDDY uses all of the exact same chemical compositions as the applicant, skilled artisans would find it apparent that the photoluminescence intensity enhancement of the ICE layer would also possess the same improvement range as claimed here.
Since the examiner does not have proper means to conduct experiments, the burden of proof is now shifted to applicants to show otherwise. In re Best, 562 F.2d 1252, 195 USPQ 430 (CCPA 1977); In re Fitzgerald, 205 USPQ 594 (CCPA 1980).
Regarding claim 20, modified REDDY teaches the method of claim 15, wherein the ICE layer comprises a compound selected from the group consisting of: isothiourea, AET; 4-FTP; 4-ATP; EDT (JASIENIAK teaches EDT); L-Cys; TGA; OT; -FBM; TDF-OT; or 4-TFMBM.
Regarding claim 22, modified REDDY teaches the method of claim 15, wherein the passivating step comprises: contacting the surface of the absorber layer with an alkaline passivation agent, and wherein the alkaline passivation agent comprises at least one of: sodium hydroxide (NaOH), potassium hydroxide (KOH), or tetramethylammonium hydroxide (TMAH) (CHRISTENSEN teaches the KOH and NaOH alkaline passivation agent).
Regarding claim 24, modified REDDY teaches the method of claim 15, wherein providing the absorber layer stack comprises forming the absorber layer over a substrate stack (REDDY teaches a substrate with CdTe type II-VI), wherein the absorber layer comprises a type II-VI semiconductor, and wherein forming the absorber layer further comprises doping (CdTe can be doped with extra cadmium or telluride, see CHRISTENSEN, para. 35; can also dope with larger bandgap materials, para. 9), passivating; and removing oxides from the type II-VI semiconductor prior to depositing the ICE layer (see CHRISTENSEN generally teaching the passivating and removing oxides).
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Regarding claim 25, modified REDDY teaches the method of claim 15, wherein the ICE layer comprises a monolayer of thiol ligands with dipole moments aligned relative to the second surface of the absorber layer (EDT only forms a monolayer of ligand, and since it is the exact same material as applicant it would be expected by skilled artisans to also assume the exact same dipole alignment).
Regarding claim 26, modified REDDY teaches the method of claim 15, wherein the ICE layer comprises a thiophenol or alkanethiol compound (EDT is an alkanethiol).
Conclusion
No claim is allowed.
Contact Information
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ANGELO TRIVISONNO whose telephone number is (571) 272-5201 or by email at <angelo.trivisonno@uspto.gov>. The examiner can normally be reached on MONDAY-FRIDAY, 9:00a-5:00pm EST. The examiner's supervisor, NIKI BAKHTIARI, can be reached at (571) 272-3433.
/ANGELO TRIVISONNO/
Primary Examiner
Prosecution Insights