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 instant claims contain the transitional phrase “comprising”. Per MPEP 2111.03 ‘The transitional term “comprising”, which is synonymous with “including,” “containing,” or “characterized by,” is inclusive or open-ended and does not exclude additional, unrecited elements or method steps'. This open-ended definition has been taken into consideration in the following rejections.
Claims 1-19 are rejected under 35 U.S.C. 103 as being unpatentable over US 2019/0006556 A1 to Park et al. (hereinafter Park).
Regarding claim 1, Park discloses a method for preparing a quantum dot (para [0033]-[0036]), the method comprising:
forming a core (first precursors, para [0035]) selected from a group comprising I-III-VI compounds, such as CuInGaS, para [0025]), which comprises atoms of copper, indium, gallium, and sulfur; and
forming a shell surrounding the core by reacting the surface of the core (para [0036]) with a hydrofluoric acid (first halogen source HF, para [0046]), a precursor selected from a group including Group II element precursors (para [0041]), and a precursor selected form a group including Group VI element precursors (para [0042]).
It would be obvious to one of ordinary skill in the art to select particular core materials, such as CuInGaS, and particular shell materials, such as II-VI compounds, to prepare a quantum dot that emits the desired color of light (corresponding to the desired energy bandgap) with high color purity (para [0003]).
Regarding claim 2, Park discloses the method of claim 1, wherein the forming of the shell comprises:
reacting the surface of the core (first semiconductor nanocrystal) with the hydrofluoric acid (first halogen source, HF, para [0134]) and
reacting the surface of the core with the Group II element precursor and the Group VI element precursor (at least two second precursors, para [0120]). Park is silent regarding the limitation “wherein halogen ions bonded to the surface of the core are removed through the reacting of the surface of the core with the hydrofluoric acid”.
However, Park does teach an overlapping method to prepare an overlapping core/shell quantum dot, as discussed above. See MPEP 2112.01(I), which states that ‘Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established…"When the PTO shows a sound basis for believing that the products of the applicant and the prior art are the same, the applicant has the burden of showing that they are not."…Therefore, the prima facie case can be rebutted by evidence showing that the prior art products do not necessarily possess the characteristics of the claimed product’. Park teaches an overlapping method of making an overlapping quantum dot. Therefore, it would be obvious to one of ordinary skill in the art that during the Park process, halogen ions bonded to the surface of the core would be removed through the reacting of the surface of the core with the hydrofluoric acid, absent evidence to the contrary.
Regarding claim 3, Park discloses the method of claim 1, wherein the number of moles of the hydrofluoric acid is about 30 at% to 90 at% with respect to the total number of moles of the copper atom, the indium atom, the gallium atom, and the sulfur atom (all atoms in the core, para [0095]), which overlaps the instantly claimed range of about 2 times to about 7 times with respect to the total number of moles of the copper atom, the indium atom, the gallium atom, and the sulfur atom. See MPEP 2144.05(I), which states that ‘In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists’.
Regarding claim 4, Park discloses the method of claim 1, wherein the forming of the core comprises:
providing a first mixture including:
a ligand, and
a first (core) precursor material including a copper precursor, an indium precursor, and a gallium precursor; and adding a sulfur (second) precursor to the first mixture to react the first precursor material with the sulfur precursor (para [0033]-[0035]) to form CuInGaS, para [0025], as discussed above.
Regarding claim 5, Park discloses the method of claim 4, wherein the copper precursor, the indium precursor, and the gallium precursor are each a metal halide (metal containing halogen, para [0029]).
Regarding claim 6, Park discloses the method of claim 4, wherein
the copper precursor is represented by Formula 1,
the indium precursor is represented by Formula 2, and
the gallium precursor is represented by Formula 3:
[Formula 1] CuXₘ, such as CuCl
[Formula 2] InXₘ, such as InCl3
[Formula 3] GaXₘ, such as GaCl3 (para [0029])
wherein in Formula 1 to Formula 3,
X is Cl, Br, or I, and
m is determined according to the valence of Cu, In, or Ga, and is each independently an
integer from 1 to 3 (para [0029]).
Regarding claim 7, Park discloses the method of claim 4, wherein the sulfur precursor comprises at least one of sulfur-trioctylphosphine (S-TOP), sulfur-tributylphosphine (S-TBP), sulfur-triphenylphosphine (S-TPP), sulfur-trioctylamine (S-TOA), octanethiol, dodecanethiol (DDT), bis(trimethylsilyl) sulfide (para [0133]), and octadecane thiol (para [0117]).
Regarding claim 8, Park discloses the method of claim 1, wherein the forming of the shell comprises:
adding at least two second precursors (para [0122]) comprising;
adding a Group II element precursor, such as a zinc compound (para [0125]), and a solvent comprising the hydrofluoric acid to a second mixture comprising the core; and
adding a Group VI element precursor, such as octane thiol (para [0133]), to the second mixture to react the Group II element precursor and the Group VI element precursor (para [0119]-[0120]).
Regarding claim 9, Park discloses the method of claim 8, wherein the reacting of the Group II element precursor and the Group VI element precursor is each performed at a first temperature, and the first temperature is greater than or equal to about 100 °C (para [0129]), which overlaps the instantly claimed range of equal to or greater than about 160 °C. See MPEP 2144.05(I), cited above.
Regarding claim 10, Park discloses the method of claim 9, wherein the adding of the solvent comprising the hydrofluoric acid is performed at a second temperature of greater than or equal to about 100 °C (para [0137]), that overlaps the first temperature. Park further discloses that the first and second temperatures can be the same or different (para [0123]). The reference is silent regarding the second temperature as lower than the first temperature.
However, it would be obvious to employ the second temperature as lower than the first temperature when different temperatures are used to facilitate formation of quantum dots comprising at least two different first and/or second precursors (para [0123]). In this manner multi-layered shells can be formed on the cores thereby effectively passivating a surface of the core, increasing luminous efficiency, and enhancing the stability of the quantum dot (para [0085]).
Regarding claim 11, Park discloses a quantum dot comprising:
a core (first semiconductor nanocrystal, para [0085]) selected from a group comprising copper, indium, gallium, and sulfur (CuInGaS, para [0106]); and
a shell surrounding the core (para [0085]) and comprising fluorine (para [0086]) and a compound selected from a group that includes Group II-VI compounds (para [0100]).
It would be obvious to one of ordinary skill in the art to select particular core materials, such as CuInGaS, and particular shell materials, such as II-VI compounds, to provide a quantum dot that emits the desired color of light (corresponding to the desired energy bandgap) with high color purity (para [0003]).
Regarding claim 12, Park discloses the quantum dot of claim 11, wherein the Group II-VI compound is ZnS (para [0103]).
Regarding claim 13, Park discloses the quantum dot of claim 11, wherein an average particle diameter of the quantum dot is in a range of about 1 nm to about 100 nm (para [0115]), which overlaps the instantly claimed range of about 3 nm to about 20 nm. See MPEP 2144.05(I), cited above.
Regarding claim 14, Park discloses the quantum dot of claim 11, wherein a central wavelength of the quantum dot is in a range of about 400 nm to about 600 nm, about 600 nm to about 700 nm, or about 550 nm to about 650 nm (para [0114]), which all overlap the instantly claimed range of about 500 nm to about 650 nm. See MPEP 2144.05(I), cited above.
Regarding claim 15, Park discloses the quantum dot of claim 11, wherein a full width at half maximum of an emission wavelength spectrum of the quantum dot is less than or equal to about 50 nm (para [0113]), which falls within the instantly claimed range of equal to or less than 60 nm.
Regarding claim 16, Park discloses the quantum dot of claim 11, wherein a quantum yield of the quantum dot is greater than or equal to about 85% (para [0113]), which falls within the instantly claimed range of equal to or greater than about 80%.
Regarding claim 17, Park discloses the quantum dot of claim 11, but is silent regarding the limitation “wherein a quantum yield retention rate of the quantum dot is represented by Equation 1, and
the quantum yield retention rate is equal to or greater than about 90%:
[Equation 1]
Quantum yield retention rate = A1/A0
wherein in Equation 1,
A₁ is a quantum yield of the quantum dot measured when blue light having a brightness of 200 nit is emitted for 120 minutes, and
A₀ is a quantum yield of the quantum dot before the emitting of the blue light.”.
However, Park does teach an overlapping quantum dot made by an overlapping method, as discussed above. Therefore, per MPEP 2112.01(I) cited above, one of ordinary skill in the art would expect an overlapping retention ratio under the same conditions, absent evidence to the contrary.
Regarding claim 18, Park discloses the quantum dot of claim 11, wherein a ratio of the total number of indium atoms and gallium atoms in the entire quantum dot to the number of copper atoms in the entire quantum dot is 2 in CuInGaS (para [0106]), which is in a range of about 1 to about 10.
Regarding claim 19, Park discloses the quantum dot of claim 11, wherein a thickness of the shell is greater than or equal to about 0.6 nm (para [0094]), which overlaps the instantly claimed range of equal to less than about 5 nm. See MPEP 2144.05(I), cited above.
Claim 20 is rejected under 35 U.S.C. 103 as being unpatentable over Park in view of US 2018/0179441 A1 to Park et al. (hereinafter Park441).
Regarding claim 20, Park discloses a light emitting element, such as a display (para [0150]) comprising:
a stacked structure that contains an emission layer comprising a quantum dot (QD sheet, para [0150] and Fig. 3),
wherein the quantum dot comprises:
a core (first semiconductor nanocrystal, para [0085]) selected from a group comprising copper, indium, gallium, and sulfur (CuInGaS, para [0106]); and
a shell surrounding the core (para [0085]) and comprising fluorine (para [0086]) and a compound selected from a group that includes Group II-VI compounds (para [0100]). It would be obvious to one of ordinary skill in the art to select particular core materials, such as CuInGaS, and particular shell materials, such as II-VI compounds, to prepare a quantum dot that emits the desired color of light (corresponding to the desired energy bandgap) with high color purity (para [0003]).
Park does not further disclose the stacked structure.
However, Park411 discloses a light emitting element, such as a display (para [0222]) comprising:
a first electrode (1);
a hole transport region disposed on the first electrode (2);
an emission layer disposed on the hole transport region and comprising a quantum dot (3);
an electron transport region disposed on the emission layer (4); and
a second electrode disposed on the electron transport region (5, para [0223] and Fig. 4).
It would be obvious to one of ordinary skill in the art to employ a stacked element configuration comprising the electrode layers, electron transport region, and electron transport region as set forth in Park411 as the stacked element configuration of Park to provide a display with the desired combination of physical properties, such as energy bandgaps, and photoluminescence properties, such as color purity (Park411, para [0003] and [0221], and Park, para and [0150]).
Conclusion
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/L.E./Examiner, Art Unit 1734
/Matthew E. Hoban/Primary Examiner, Art Unit 1734
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