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 .
Priority
Acknowledgment is made of applicant’s claim for foreign priority under 35 U.S.C. 119 (a)-(d). The certified copy has been filed in parent Application No. KR10-2023-0087889, filed on July 6, 2023.
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Information Disclosure Statement
The information disclosure statement filed October 21, 2024 fails to comply with 37 CFR 1.98(a)(2), which requires a legible copy of each cited foreign patent document; each non-patent literature publication or that portion which caused it to be listed; and all other information or that portion which caused it to be listed. It has been placed in the application file, but the information referred to therein has not been considered. The cited foreign patent document not provided is “WO2022019019A1”. The document is likely a typo since “WO2022190190A1” is provided and cited in the IDS filed on October 24, 2024.
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, 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.
Claims 1, 5-13, 15-17, 19, and 21-24 are rejected under 35 U.S.C. 103 as being unpatentable over Kwang Hee et al (KR20190106819A).
Regarding claim 1, Kwang Hee teaches preparation of a quantum dot with an organic ligand coordinated (or bonded) to a surface of the quantum dot whereby the organic ligand comprises two separate ligands (a first ligand and a second ligand which are different from one another), thus forming a quantum dot complex. The first ligand has the following formula:
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950
507
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whereby k1 is zero or an integer of 1 or more and k2 is 1 or 2. Therefore, Kwang Hee teaches the first ligand includes a thiol group at “an end of the first ligand” (right hand side SM whereby M is a hydrogen). It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to select for “M” as a hydrogen group as a known potential organic ligand composition such that the first ligand comprises a thiol group at an end of the first ligand and arrive at the limitation as claimed. Kwang Hee teaches a second ligand having a formula:
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. As suggested in the first ligand, the second ligand may also contain a thiol group at an end when “M” is a hydrogen. The opposite end “R2” is disclosed as potentially being “-C(=O)OR’ wherein R' is hydrogen or a straight or branched chain alkyl group”, thus R2 can be a carboxyl group at the opposite end when R’ is hydrogen. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to select from any of the overlapping identities for the second ligand whereby a thiol group is included at one end and a carboxyl group at the opposite end as known embodiments of a second ligand for quantum dot complexes having improved dispersibility and improved electroluminescent properties and arrive at the limitation as claimed. Therefore, Kwang Hee teaches the claimed “A quantum dot complex comprising: a quantum dot; a first ligand bonded to a surface of the quantum dot and including a thiol group at an end of the first ligand; and a second ligand different from the first ligand, bonded to a surface of the quantum dot, and including a thiol group at an end of the second ligand and a carboxyl group at an opposite end of the second ligand”.
Regarding claim 5, Kwang Hee teaches the quantum dot complex of claim 1. As described in the rejection of claim 1 above, the second ligand of Kwang Hee has the formula:
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. As suggested in the first ligand, the second ligand may also contain a thiol group at an end when “M” is a hydrogen. The opposite end “R2” is disclosed as potentially being “-C(=O)OR’ wherein R' is hydrogen or a straight or branched chain alkyl group”, thus R2 can be a carboxyl group at the opposite end when R’ is hydrogen. Y2 can be a direct bond between S and L2. L2 can be a carbon atom alone (matches claimed Formula 1 whereby R is a hydrogen atom and n=1) or L2 can be a substituted or unsubstituted carbon chain up to 8 carbon atoms which overlaps within the embodiment of Formula 1 as claimed. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to select from the overlapping portions of disclosed identities for M, R2, Y2, L2, and k3=k4=1 as known acceptable components for preparing a second ligand to coordinate with a quantum dot and form a complex having improved dispersibility and electroluminescent properties and arrive at the invention as claimed. Thus, Kwang Hee teaches the claimed “
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789
657
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”.
Regarding claim 6, Kwang Hee teaches the quantum dot complex of claim 1. As claimed, the common names for the formulas for LD1, LD2, LD3, and LD4 are 3-mercaptopropanoic acid, dihydrolipoic acid, cysteine, and thioglycolic acid, respectively. Kwang Hee specifically discloses the second thiol compound or second ligand can be 3-mercaptopropionic acid, cysteine, or thioglycolic acid among other disclosed organic compounds. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to select from any of the overlapping compounds as the second ligand as a known thiol compound capable of improving dispersibility and electroluminescent properties of quantum dots and arrive at the invention as claimed. Thus, Kwang Hee teaches the claimed “
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382
650
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”.
Regarding claim 7, Kwang Hee teaches the quantum dot complex of claim 1. Kwang Hee teaches that the content of the first ligand may be between 1-15wt% based on the total weight of the quantum dots. The second ligand may also be between 1-15wt% based on the total weight of the quantum dots. Thus, the weight or mass ratios between first and second ligands can be taken proportionately with respect to total weight of the quantum dots. Therefore, the mass ratio between the first and second ligand is (1-15):(1-15) or within the range of 1:15 to 15:1 which overlaps with the claimed range of “about 99:1 to about 50:50”. Overlapping ranges have been held to present a prima facie case of obviousness over the prior art. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to select from the overlapping portion of the range as known weight ratios between first and second ligands that enable an improvement of dispersibility and electroluminescent properties of a prepared quantum dot complex to arrive at the invention as claimed. Thus, Kwang Hee teaches the claimed “The quantum dot complex of claim 1, wherein the first ligand and the second ligand are at a weight ratio of about 99:1 to about 50:50”.
Regarding claim 8, Kwang Hee teaches the quantum dot complex of claim 1. Kwang Hee teaches that the quantum dot may be provided with a core, or a core and one or more shells whereby the ligands are bonded to the surface (thus surface of the shell if a shell is provided). In the provided examples, Kwang Hee uses a ZnTeSe/ZnSeS core/shell quantum dot having two different ligands bound to the surface. Although Kwang Hee does not provide first and second ligands in examples that necessarily meet the limitations of claim 1, as described in the rejection of claim 1 (and rejections of claims 5-6), Kwang Hee teaches alternatives that do meet such limitations and would be obvious to employ as known substitutes. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to substitute the first and second ligands of the ZnTeSe/ZnSeS core/shell quantum dot for known alternative first and second ligands that overlap with the disclosed first and second ligands with a predictable result of preparing a QD complex with improved dispersibility and electroluminescent properties and arrive at the invention as claimed. Thus, Kwang Hee teaches the claimed “The quantum dot complex of claim 1, wherein the quantum dot comprises a core and a shell surrounding the core, and the first ligand and the second ligand are each bonded to a surface of the shell”.
Regarding claim 9, Kwang Hee teaches the quantum dot complex of claim 8. As described in the rejection of claim 8, Kwang Hee provides a ZnTeSe/ZnSeS core/shell, thus a core and shell that comprise different semiconductor nanocrystals. Zn is a Group II element, and Te, Se, and S are Group VI elements. Therefore, the first and second semiconductor nanocrystals each include a Group II-VI compound. Thus, Kwang Hee teaches the claimed “The quantum dot complex of claim 8, wherein the core comprises a first semiconductor nanocrystal, and the shell comprises a second semiconductor nanocrystal different from the first semiconductor nanocrystal, and the first semiconductor nanocrystal and the second semiconductor nanocrystal each include at least one of a Group II-VI compound, a Group III-VI compound, a Group I-III-VI compound, a Group III-V compound, a Group III-II-V compound, a Group IV-VI compound, a Group IV element, and a Group IV compound”.
Regarding claim 10, Kwang Hee teaches the quantum dot complex of claim 1. In the provided examples, Kwang Hee uses a ZnTeSe/ZnSeS core/shell quantum dot having two different ligands bound to the surface. Zn is a Group II element, and Te, Se, and S are Group VI elements, thus the quantum dot comprises two or more elements selected from Group II and Group VI elements, excluding Cd. Although Kwang Hee does not provide first and second ligands in examples that necessarily meet the limitations of claim 1, as described in the rejection of claim 1 (and rejections of claims 5-6), Kwang Hee teaches alternatives that do meet such limitations and would be obvious to employ as known substitutes. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to substitute the first and second ligands of the ZnTeSe/ZnSeS core/shell quantum dot for known alternative first and second ligands that overlap with the disclosed first and second ligands with a predictable result of preparing a QD complex with improved dispersibility and electroluminescent properties and arrive at the invention as claimed. Thus, Kwang Hee teaches the claimed “The quantum dot complex of claim 1, wherein the quantum dot comprises two or more elements selected from Group II and Group VI elements, excluding Cd.”.
Regarding claim 11, Kwang Hee teaches the quantum dot complex of claim 10. In the provided examples, Kwang Hee uses a ZnTeSe/ZnSeS core/shell quantum dot having two different ligands bound to the surface. Thus, the quantum dot comprises ZnSeTe. Therefore, Kwang Hee teaches the claimed “The quantum dot complex of claim 10, wherein the quantum dot comprises ZnSeTe”.
Regarding claim 12, Kwang Hee teaches the quantum dot complex of claim 1. Kwang Hee obtains photoluminescence spectras of quantum dots with an irradiation wavelength of 458nm or 532nm. The irradiation wavelength is understood to be an excitation wavelength which is analogous to an absorbance as quantum dots generally work on the principle of absorbing light at a wavelength (excitation wavelength) and emitting light at a different wavelength (emission wavelength). A wavelength of 458nm is understood or can be interpreted as “about 450 nanometers” to one of ordinary skill in the art as 458nm falls within 1.78% of 450nm. Furthermore, such embodiments of quantum dots are commonly employed in light emitting devices whereby a UV or blue light source serves as an excitation source (overlaps with 300-450nm) for quantum dots to emit light in green and red spectrum such that a combination of red, green, and unabsorbed blue light produces white light in a display device. Kwang Hee teaches such an implementation for their quantum dot complexes and thus would be an obvious absorbance wavelength parameter to employ. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to ensure an absorbance or excitation wavelength within the blue and/or UV light spectrum such that the quantum dot can emit red and/or green light in a white-light emitting device and arrive at the invention as claimed. Thus, Kwang Hee teaches the claimed “The quantum dot complex of claim 1, wherein the quantum dot complex absorbs light in a range of about 300 nanometers to about 450 nanometers”.
Regarding claim 13, Kwang Hee teaches the quantum dot complex of claim 1 whose limitations are implicitly contained within the limitations of claim 13 (lines 6-11), see rejection of claim 1 above. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to select from any of the overlapping identities for the second ligand whereby a thiol group is included at one end and a carboxyl group at the opposite end as known embodiments of a second ligand for quantum dot complexes having improved dispersibility and improved electroluminescent properties and arrive at the limitation as claimed. Furthermore, Kwang Hee teaches that the quantum dot complex is to be implemented into an emission layer that is contained within a light-emitting device (thus light-emitting element). In Figs. 1 and 5, Kwang Hee teaches a general embodiment for a light-emitting device or element as pasted below:
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178
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. In Fig. 1, the first and second electrodes are members 21 and 25 respectively that face one another. Members 22 and 24 are hole transport and electron transport layers, respectively, which are a “functional layer disposed at least one of bteween the emission layer and the first electrode or between the emission layer and the second electrode”. Member 23 is the emission layer, thus sandwiched or disposed between functional layers and electrodes. The emission layer or light-emitting layer includes the quantum dot complex according to Kwang Hee. In Fig. 5, the first electrode is 160, a hole auxiliary layer 172 (a functional layer), a light emitting layer 173, an electron auxiliary layer 174 (a functional layer), and a second electrode 180 are provided similarly as described to the embodiment of Fig. 1. Thus, Kwang Hee teaches the claimed “A light-emitting element comprising: a first electrode; a second electrode facing the first electrode; an emission layer disposed between the first electrode and the second electrode and including a quantum dot complex, the quantum dot complex including: a quantum dot; a first ligand bonded to a surface of the quantum dot and including a thiol group at an end of the first ligand; and a second ligand different from the first ligand, bonded to a surface of the quantum dot, and including a thiol group at an end of the second ligand and a carboxyl group at an opposite end of the second ligand; and a functional layer disposed at least one of between the emission layer and the first electrode or between the emission layer and the second electrode”.
Regarding claim 15, Kwang Hee teaches the light-emitting element of claim 13. As described in the rejections of claims 1 and 13 above, the second ligand of Kwang Hee has the formula:
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. As suggested in the first ligand, the second ligand may also contain a thiol group at an end when “M” is a hydrogen. The opposite end “R2” is disclosed as potentially being “-C(=O)OR’ wherein R' is hydrogen or a straight or branched chain alkyl group”, thus R2 can be a carboxyl group at the opposite end when R’ is hydrogen. Y2 can be a direct bond between S and L2. L2 can be a carbon atom alone (matches claimed Formula 1 whereby R is a hydrogen atom and n=1) or L2 can be a substituted or unsubstituted carbon chain up to 8 carbon atoms which overlaps within the embodiment of Formula 1 as claimed. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to select from the overlapping portions of disclosed identities for M, R2, Y2, L2, and k3=k4=1 as known acceptable components for preparing a second ligand to coordinate with a quantum dot and form a complex having improved dispersibility and electroluminescent properties and arrive at the invention as claimed. Thus, Kwang Hee teaches the claimed “
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412
680
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”.
Regarding claim 16, Kwang Hee teaches the light-emitting element of claim 13. As claimed, the common names for the formulas for LD1, LD2, LD3, and LD4 are 3-mercaptopropanoic acid, dihydrolipoic acid, cysteine, and thioglycolic acid, respectively. Kwang Hee specifically discloses the second thiol compound or second ligand can be 3-mercaptopropionic acid, cysteine, or thioglycolic acid among other disclosed organic compounds. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to select from any of the overlapping compounds as the second ligand as a known thiol compound capable of improving dispersibility and electroluminescent properties of quantum dots and arrive at the invention as claimed. Thus, Kwang Hee teaches the claimed “
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339
612
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”.
Regarding claim 17, Kwang Hee teaches the light-emitting element of claim 13. As described in the rejection of claim 13 above, in Kwang Hee’s embodiments for the light-emitting element (Figs. 1 and 5), Kwang Hee provides two functional layers: one functional layer (member 22 of Fig. 1 and member 172 of Fig. 5) serving as a hole transport or auxiliary layer which is disposed between the first electrode (member 21 of Fig. 1 and member 160 of Fig. 5) and emission layer (member 23 of Fig. 1 and member 173 of Fig. 5) and another functional layer (member 24 of Fig. 1 and member 174 of Fig. 5) serving as an electron transport or auxiliary layer which is disposed between the second electrode (member 25 of Fig. 1 and member 180 of Fig. 5) and emission layer (member 23 of Fig. 1 and member 173 of Fig. 5). Thus, Kwang Hee teaches the claimed “The light-emitting element of claim 13, wherein the functional layer comprises: a first functional layer disposed between the first electrode and the emission layer; and a second functional layer disposed between the emission layer and the second electrode, and one of the first functional layer and the second functional layer is a hole transport region, and a remaining one of the first functional layer and the second functional layer is an electron transport region.”.
Regarding claim 19, Kwang Hee teaches the light-emitting element of claim 13 whose limitations are implicitly contained within claim 19 (line 21 pg 6 through lines 1-14 pg 7). Kwang Hee teaches implementation of the light-emitting element into a display device (Fig. 6). Kwang Hee teaches a circuit unit with the display device member 200 of Fig. 6 but does not show the circuit unit in the Fig and states it is positioned on the substrate 123 from the outside. The circuit unit is interpreted as a circuit layer. The display element layer of Kwang Hee are the members above the substrate, thus the display element layer is disposed on the circuit layer. The display element layer of Kwang Hee includes a light-emitting element (member 100, see rejection of claim 13 and Fig. 5) and includes all limitations listed on pg 7 lines 1-14. Furthermore, the display element layer of Kwang Hee also includes a pixel defining layer (member 125) “having an opening overlapping the first electrode 160 is disposed on the planarization layer 124”, thus the pixel defining layer has a pixel opening defined. Therefore, Kwang Hee teaches the claimed “A display device comprising: a circuit layer; and a display element layer disposed on the circuit layer and including a light-emitting element and a pixel defining layer in which a pixel opening is defined, the light-emitting element including: a first electrode; a second electrode facing the first electrode; an emission layer disposed between the first electrode and the second electrode and including a quantum dot complex, the quantum dot complex including: a quantum dot; a first ligand bonded to a surface of the quantum dot and including a thiol group at an end of the first ligand; and a second ligand different from the first ligand, bonded to a surface of the quantum dot, and including a thiol group at an end of the second ligand and a carboxyl group at an opposite end of the second ligand; and a functional layer disposed at least one of between the emission layer and the first electrode or between the emission layer and the second electrode”.
Regarding claim 21, Kwang Hee teaches the display device of claim 19. The second ligand of Kwang Hee has the formula:
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. As suggested in the first ligand, the second ligand may also contain a thiol group at an end when “M” is a hydrogen. The opposite end “R2” is disclosed as potentially being “-C(=O)OR’ wherein R' is hydrogen or a straight or branched chain alkyl group”, thus R2 can be a carboxyl group at the opposite end when R’ is hydrogen. Y2 can be a direct bond between S and L2. L2 can be a carbon atom alone (matches claimed Formula 1 whereby R is a hydrogen atom and n=1) or L2 can be a substituted or unsubstituted carbon chain up to 8 carbon atoms which overlaps within the embodiment of Formula 1 as claimed. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to select from the overlapping portions of disclosed identities for M, R2, Y2, L2, and k3=k4=1 as known acceptable components for preparing a second ligand to coordinate with a quantum dot and form a complex having improved dispersibility and electroluminescent properties and arrive at the invention as claimed. Thus, Kwang Hee teaches the claimed “
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411
613
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”.
Regarding claim 22, Kwang Hee teaches the light-emitting element of claim 19. As claimed, the common names for the formulas for LD1, LD2, LD3, and LD4 are 3-mercaptopropanoic acid, dihydrolipoic acid, cysteine, and thioglycolic acid, respectively. Kwang Hee specifically discloses the second thiol compound or second ligand can be 3-mercaptopropionic acid, cysteine, or thioglycolic acid among other disclosed organic compounds. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to select from any of the overlapping compounds as the second ligand as a known thiol compound capable of improving dispersibility and electroluminescent properties of quantum dots and arrive at the invention as claimed. Thus, Kwang Hee teaches the claimed “
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383
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”.
Regarding claim 23, Kwang Hee teaches the display device of claim 19. In Kwang Hee’s embodiments for the light-emitting element (Figs. 1 and 5) contained within the display device (Fig. 6), Kwang Hee provides two functional layers: one functional layer (member 22 of Fig. 1 and member 172 of Fig. 5) serving as a hole transport or auxiliary layer which is disposed between the first electrode (member 21 of Fig. 1 and member 160 of Fig. 5) and emission layer (member 23 of Fig. 1 and member 173 of Fig. 5) and another functional layer (member 24 of Fig. 1 and member 174 of Fig. 5) serving as an electron transport or auxiliary layer which is disposed between the second electrode (member 25 of Fig. 1 and member 180 of Fig. 5) and emission layer (member 23 of Fig. 1 and member 173 of Fig. 5). Thus, Kwang Hee teaches the claimed “The display device of claim 19, wherein the functional layer comprises: a first functional layer disposed between the first electrode and the emission layer; and a second functional layer disposed between the emission layer and the second electrode, and one of the first functional layer and the second functional layer is a hole transport region, and a remaining one of the first functional layer and the second functional layer is an electron transport region”.
Regarding claim 24, Kwang Hee teaches the display device of claim 19. The display device is represented in Fig. 6
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whereby the pixel defining layer is 125 and the light-emitting element is member 100 containing first electrode 160, second electrode 180, and light emitting device layer 170 which contains a light emission layer (member 173 of Fig. 5). As depicted in Fig. 6, the pixel defining layer has an opening whereby the light-emitting element is contained within (Kwang Hee states the opening overlaps the first electrode and the light emitting device layer 170 may be positioned in each opening of the pixel defining layer 125). Kwang Hee clarifies that the pixel region in which each light emitting device layer 170 is positioned may be defined by the pixel defining layer. The light emitting device layer contains two functional layers which are hole transport and electron transport layers (members 172 and 174 of Fig. 5). Therefore, the functional layer overlaps the emission layer and the pixel defining layer. Thus, Kwang Hee teaches the claimed “The display device of claim 19, wherein the emission layer is disposed in the pixel opening, and the functional layer is a common layer overlapping the emission layer and the pixel defining layer.”.
Claims 2-4, 14, and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Kwang Hee et al, as evidenced by Ha et al (US PGPub 20220195289).
Regarding claim 2, Kwang Hee teaches the quantum dot complex of claim 1. Although Kwang Hee does not specifically disclose what constitutes the “head” and “end” portions of the first and second ligands, it is well known in the art that the sulfur atom of the thiol group bonds or coordinates to the surface of quantum dot compositions whereby the quantum dot contains Zn at the outer surface as evidenced by Ha and thus would be considered “inherent” of the provided ligands of Kwang Hee. Ha discloses in paragraphs [0153-154] that the thiol group of each head portions of first and second ligands bind to Zn to form a quantum dot complex. Thus, in Kwang Hee’s embodiments, the thiol group of the ligands will be considered a head portion as Kwang Hee provides Zn in the outermost layer or surface of the provided quantum dot examples. Therefore, the remaining L1 and R1 groups in the first ligand of Kwang Hee are considered a first tail portion which extends from the first head portion including a thiol group. Both L1 and R1 can be substituted or unsubstituted alkyl groups or a carbon atom. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to select for a tail portion that is a substituted or unsubstituted alkyl group in the first ligand of Kwang Hee as a known suitable identity of such first ligand capable of improving dispersibility and electroluminescent properties of a quantum dot complex and arrive at the invention as claimed. Thus, Kwang Hee teaches the claimed “The quantum dot complex of claim 1, wherein the first ligand comprises a first head portion including a thiol group, and a first tail portion extending from the first head portion and including an alkyl group”.
Regarding claim 3, Kwang Hee teaches the quantum dot complex of claim 2. L1 of the first ligand of Kwang Hee can be a carbon atom or an alkyl group of C1 to C10 (thus up to 11 carbon atoms for part of the tail portion). R1 can be hydrogen or a substituted or unsubstituted C1 to C30 alkyl group (thus up to 30 carbon atoms for the remaining tail portion). The tail portion of Kwang Hee can thus range from containing 1-41 carbon atoms in the alkyl group which overlaps with the 2-20 carbon atoms as claimed. Overlapping ranges have been held to present a prima facie case of obviousness over the prior art. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to select from the overlapping portion of the range as a known suitable amount of carbons to be contained within the alkyl group of the tail portion of the first ligand known to improve dispersibility and electroluminescent properties of a quantum dot complex and arrive at the invention as claimed. Thus, Kwang Hee teaches the claimed “The quantum dot complex of claim 2, wherein the first tail portion comprises an alkyl group having 2 carbon atoms to 20 carbon atoms”.
Regarding claim 4, Kwang Hee teaches the quantum dot complex of claim 1. Although Kwang Hee does not specifically disclose what constitutes the “head” and “end” portions of the first and second ligands, it is well known in the art that the sulfur atom of the thiol group bonds or coordinates to the surface of quantum dot compositions whereby the quantum dot contains Zn at the outer surface as evidenced by Ha and thus would be considered “inherent” of the provided ligands of Kwang Hee. Ha discloses in paragraphs [0153-154] that the thiol group of each head portions of first and second ligands bind to Zn to form a quantum dot complex. Thus, in Kwang Hee’s embodiments, the thiol group of the ligands will be considered a head portion as Kwang Hee provides Zn in the outermost layer or surface of the provided quantum dot examples. As described in the rejection of claim 1, Kwang Hee enables an end portion of the second ligand to be a carboxyl group (R2) which would thus be “an end portion spaced apart from the surface of the quantum dot and including a carboxyl group” since the thiol group is known to coordinate to the quantum dot surface via Zn bonding as evidenced by Ha. L2 would thus be considered a “second tail portion disposed between the second head portion and the end portion”. Therefore, Kwang Hee teaches the claimed “The quantum dot complex of claim 1, wherein the second ligand comprises a second head portion including a thiol group, an end portion spaced apart from the surface of the quantum dot and including a carboxyl group, and a second tail portion disposed between the second head portion and the end portion”.
Regarding claim 14, Kwang Hee teaches the light-emitting element of claim 13. As described in the rejections of claims 2 and 4 above, Kwang Hee’s first and second ligands comprise the limitations as claimed which are implicitly contained within claim 14. Although Kwang Hee does not specifically disclose what constitutes the “head” and “end” portions of the first and second ligands, it is well known in the art that the sulfur atom of the thiol group bonds or coordinates to the surface of quantum dot compositions whereby the quantum dot contains Zn at the outer surface as evidenced by Ha and thus would be considered “inherent” of the provided ligands of Kwang Hee. Ha discloses in paragraphs [0153-154] that the thiol group of each head portions of first and second ligands bind to Zn to form a quantum dot complex. Thus, in Kwang Hee’s embodiments, the thiol group of the ligands will be considered a head portion as Kwang Hee provides Zn in the outermost layer or surface of the provided quantum dot examples. Therefore, the remaining L1 and R1 groups in the first ligand of Kwang Hee are considered a first tail portion which extends from the first head portion including a thiol group. Both L1 and R1 can be substituted or unsubstituted alkyl groups or a carbon atom. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to select for a tail portion that is a substituted or unsubstituted alkyl group in the first ligand of Kwang Hee as a known suitable identity of such first ligand capable of improving dispersibility and electroluminescent properties of a quantum dot complex and arrive at the invention as claimed. As described in the rejection of claim 1, Kwang Hee enables an end portion of the second ligand to be a carboxyl group (R2) which would thus be “an end portion spaced apart from the surface of the quantum dot and including a carboxyl group” since the thiol group is known to coordinate to the quantum dot surface via Zn bonding as evidenced by Ha. L2 would thus be considered a “second tail portion disposed between the second head portion and the end portion”. Therefore, Kwang Hee teaches the claimed “The light-emitting element of claim 13, wherein the first ligand comprises a first head portion including a thiol group, and a first tail portion extending from the first head portion and including an alkyl group, and the second ligand comprises a second head portion including a thiol group, an end portion spaced apart from the surface of the quantum dot and including a carboxyl group, and a second tail portion disposed between the second head portion and the end portion.”.
Regarding claim 20, Kwang Hee teaches the display device of claim 19. As described in the rejections of claims 2, 4, and 14 above, Kwang Hee’s first and second ligands comprise the limitations as claimed which are implicitly contained within claim 20. Although Kwang Hee does not specifically disclose what constitutes the “head” and “end” portions of the first and second ligands, it is well known in the art that the sulfur atom of the thiol group bonds or coordinates to the surface of quantum dot compositions whereby the quantum dot contains Zn at the outer surface as evidenced by Ha and thus would be considered “inherent” of the provided ligands of Kwang Hee. Ha discloses in paragraphs [0153-154] that the thiol group of each head portions of first and second ligands bind to Zn to form a quantum dot complex. Thus, in Kwang Hee’s embodiments, the thiol group of the ligands will be considered a head portion as Kwang Hee provides Zn in the outermost layer or surface of the provided quantum dot examples. Therefore, the remaining L1 and R1 groups in the first ligand of Kwang Hee are considered a first tail portion which extends from the first head portion including a thiol group. Both L1 and R1 can be substituted or unsubstituted alkyl groups or a carbon atom. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to select for a tail portion that is a substituted or unsubstituted alkyl group in the first ligand of Kwang Hee as a known suitable identity of such first ligand capable of improving dispersibility and electroluminescent properties of a quantum dot complex and arrive at the invention as claimed. As described in the rejection of claim 1, Kwang Hee enables an end portion of the second ligand to be a carboxyl group (R2) which would thus be “an end portion spaced apart from the surface of the quantum dot and including a carboxyl group” since the thiol group is known to coordinate to the quantum dot surface via Zn bonding as evidenced by Ha. L2 would thus be considered a “second tail portion disposed between the second head portion and the end portion”. Therefore, Kwang Hee teaches the claimed “The display device of claim 19, wherein the first ligand comprises a first head portion including a thiol group, and a first tail portion extending from the first head portion and including an alkyl group, and the second ligand comprises a second head portion including a thiol group, an end portion spaced apart from the surface of the quantum dot and including a carboxyl group, and a second tail portion disposed between the second head portion and the end portion”.
Claim 18 is rejected under 35 U.S.C. 103 as being unpatentable over Kwang Hee et al as applied to claim 13 above, and further in view of Zhuang (CN112342013A).
Kwang Hee teaches the light-emitting element of claim 13 and further teaches functional layers that are a hole transport or auxiliary region (member 172) disposed below the emission layer (member 173) and an electron transport or auxiliary region (member 174) disposed above the emission layer in Fig. 5:
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. The electron transport layer according to Kwang Hee may be a single layer or two or more stacked layers. Furthermore, the electron transport or auxiliary layer may be “1,4,5,8-naphthalene-tetracarboxylic dianhydride (1,4,5,8-naphthalene-tetracarboxylic dianhydride (NTCDA), vasocouproin ( bathocuproine, BCP), tris [3- (3-pyridyl) mesityl] borane .sub.(3TPYMB), LiF, Alq 3 , Gaq 3, Inq 3, Znq 2, Zn (BTZ) 2, BeBq 2” which contains organic solvents, electron transport material and is formed from a common layer composition. Kwang Hee does not provide a contact angle. In an analogous embodiment, Zhuang teaches a quantum dot film whereby a quantum dot material is coordinated with a ligand. Although the quantum dot does not possess two distinct ligands on the surface, the principles of Zhuang’s embodiment glean insight to one of ordinary skill in the art when providing a light emitting device or element. Zhuang teaches preparation of an electron transport region or hole transport layer whereby the contact angle between the liquid on the quantum dot film surface (emission layer) can be adjusted between 20° and -40° by adjusting mixing ratio of the quantum dot material, adjusting the type of the ligand, and/or adjusting the mixing proportion of the quantum dot material and the type of ligand which are all modifications that can be analogously applied to the quantum dot complex of Kwang Hee. Contact angle is known to be a measure of hydrophilicity/hydrophobicity whereby hydrophilicity is indicated by a contact angle below 90°, and both Zhuang and Kwang Hee provide ligands which impart hydrophilicity to the quantum dot complex by improving dispersibility. Thus, Zhuang provides motivation to an already hydrophilic composition of Kwang Hee to push towards higher hydrophilicity since a low contact angle (-40° to 20°) enables effective wetting and spreading on the quantum dot film or emission layer to obtain a uniform, flat film and improve transmission capabilities according to Zhuang. Overlapping ranges have been held to present a prima facie case of obviousness over the prior art. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to select from the overlapping portion of the range such that the contact angle reaches below 15° by modifying the quantum dot material, the ligand compositions, and/or ligand and quantum dot mixing ratios of the complex provided by Kwang Hee, as informed by Zhuang, in order to obtain a uniform film, improve wetting and spreading on the emission layer in order to improve transmission capabilities and arrive at the invention as claimed. Thus, Kwang Hee and Zhuang teach the claimed “The light-emitting element of claim 13, wherein the functional layer comprises a hole transport region disposed below the emission layer, and an electron transport region disposed above the emission layer, the electron transport region is formed from a common layer composition including an electron transport material and an organic solvent, and a contact angle of the organic solvent with respect to the emission layer is 15° or less”.
Claim 25 is rejected under 35 U.S.C. 103 as being unpatentable over Kwang Hee et al as applied to claim 19 above, and further in view of Ha et al (US PGPub 20220195289).
Kwang Hee teaches the display device of claim 19 but does not specifically disclose separating the light-emitting element across three emission layers for different wavelengths of light. Kwang Hee provides quantum dot complexes that emit different wavelengths of light into one emission layer. However, it is readily understood in the art that such embodiments can be single layers of mixed composition or split into individual layers that emit distinct wavelengths of light. Ha et al teach such embodiments for their analogous quantum dot complex that is implemented into a display device. Although Ha does not teach a quantum dot complex that contains the same ligand modifications of Kwang Hee, it can be readily understood that the device implementations can be readily swapped and implemented across embodiments regardless of quantum dot composition. In paragraphs [0163-168], Ha teaches a plurality of light-emitting elements ED-1, ED-2, and ED-3 which may emit light of different wavelengths (red, blue, and green) and may each include different quantum dot complexes to emit such wavelengths of light. Each light-emitting element is a distinct layer. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to separate the emission layers into distinct emission layers that individually emit distinct wavelengths of light as a known alternative embodiment of Kwang Hee for providing display devices, as informed by Ha, with a predicted result of preparing a display device having improved electroluminescent properties and arrive at the invention as claimed. Thus, Kwang Hee and Ha teach the claimed “The display device of claim 19, wherein the light-emitting element comprises a first light-emitting element including a first emission layer which emits blue light, a second light-emitting element including a second emission layer which emits green light, and a third light-emitting element including a third emission layer which emits red light, and at least one of the first emission layer, the second emission layer, or the third emission layer comprises the quantum dot complex”.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Takata et al (US PGPub 20220384753) provide relevant hydrophilic ligands that qualify as first or second ligands as claimed for use in relevant quantum dot compositions. Yaguchi (WO2022190190A1) teaches conversion of first ligands coordinated on a surface of a quantum dot to a second ligand.
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/NWFG/Examiner, Art Unit 1759
/MELVIN C. MAYES/Supervisory Patent Examiner, Art Unit 1759
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