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. KR10-2021-0173063, filed on 12/06/2021.
Information Disclosure Statement
The information disclosure statements (IDSs) submitted on 12/05/2022, 06/02/2025, and 12/10/2025 were filed after the mailing date of the instant application on 12/05/2022. The submissions are in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statements are being considered by the examiner.
Claim Objections
Claim 4 is objected to because of the following informalities:
The syntax of claim 4 is unclear. It would make more sense to use the wording, “wherein the emission layer [[is to]] emits blue light.
Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 1-20 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the enablement requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to enable one skilled in the art to which it pertains, or with which it is most nearly connected, to make and/or use the invention.
Independent claim 1 requires a first p-dopant in a first hole transporting layer with a first hole-transporting compound and second p-dopant in a second hole transporting layer with a second hole-transporting compound wherein the absolute value of the lowest unoccupied molecular orbital (LUMO) energy of the second p-dopant is greater than the absolute value of the LUMO energy of the first p-dopant. However, the present application does not provide the person having ordinary skill in the art with a sufficient disclosure to effectuate these limitations. For example, the present application does not disclose under what specific conditions and environment the LUMO of each p-dopant is measured, nor how these values can be reasonably obtained, nor does the specification provide direction on how additional combinations of p-dopants which meet this requirement can be reasonably formed. As such, a first p-dopant in a first hole transporting layer with a first hole-transporting compound, and second p-dopant in a second hole transporting layer with a second hole-transporting compound, wherein the absolute value of the lowest unoccupied molecular orbital (LUMO) energy of the second p-dopant is greater than the absolute value of the LUMO energy of the first p-dopant is not enabled by the application, as originally filed.
The discussion points set forth below are evidenced by Sworakowski, J., 2018, How accurate are energies of HOMO and LUMO levels in small-molecule organic semiconductors determined from cyclic voltammetry or optical spectroscopy?, Synthetic Metals, 235, 125-130.
Sworakowski teaches that LUMO energies may be obtained using a variety of methods including IPES, cyclic voltammetry (CV) and UV-VIS. Of these methods, LUMO values obtained using IPES are typically accepted as “true” LUMO values. However, LUMO values determined using CV and UV-VIS differ from IPES values because CV values are typically more negative than IPES values, and UV-VIS values are even more negative than IPES values or CV values. The values obtained using CV and UV-VIS may differ from IPES values by up to 1 eV. Further, even LUMO values determined using IPES may differ from their actual values because LUMO values are influenced by factors including electrostatic interaction with their environment (composition of the layer) and non-uniform dispersion when incorporated into thin films (such as the instant case).
The factors set forth in In re Wands, 858 F.2d 731, 737 (Fed. Cir. 1988) are discussed below.
(A) The breadth of the claims
The present claims are directed to a light-emitting device comprising multiple hole transport layers (HTLs) and two of the HTLs comprise a host and p-dopant and the p-dopant in the second HTL has a LUMO energy level value whose absolute value is greater than the absolute value of the LUMO energy level of the first p-dopant in the first HTL. There are no further limitations regarding the method with which the LUMO is determined or any environmental factors which may be influencing the LUMO value of the p-dopants, such as the identity of the hole-transport compound. Since no limitations are present with regard to the method with which to measure the LUMO value of the p-dopant and composition of each hole transport layer, and no structural limitations are provided for either the p-dopant or hole transporting material, the claims cover a significantly broad range of methods and possible compound combinations which influence the LUMO of the p-dopants. Determining the composition for two different hole-transport layers comprising two different p-dopants with the claimed relationship, presents a burden.
(B) The nature of the invention
The invention relates to a light-emitting device comprising a plurality of hole transporting layers, of which the first HTL comprises a first hole transporting compound and first p-dopant and the second HTL comprises a second hole transporting compound and a second p-dopant, and the absolute value of the LUMO of the second p-dopant is greater than the absolute values of the LUMO of the first p-dopant.
In paragraphs [00112] through [00136] of the instant specification, the p-dopants of the claimed invention discussed as well as limitations such as “the first p-dopant compound and the second p-dopant compounds may each have a LUMO energy level (or work function) of -3.5 eV or less”. However, the method with which this value should be measured is not specified. Similarly, the LUMO energy values of HAT-CN and TCNQ are given in paragraphs [00334] and [00335] of the instant specification, but the method with which these values were obtained is not specified. This is increasingly complicated by the statement in paragraph [00112] of the instant specification which states that the charge generation material, which may be the p-dopant (paragraph 00113), may be non-uniformly dispersed in the hole transport region. As evidenced by Sworakowski above, non-uniform dispersion of a p-dopant can influence the measured LUMO value of a p-dopant even when the measurement is obtained using IPES.
These discussion points are provided in order to demonstrate that applicant is relying upon the LUMO energy level of just two p-dopants to support a genus of any conceivable p-dopant, without even specifying how the two LUMO energy level values were obtained. As the LUMO energy levels of the instant two data points are relatively close in value, and because the measured LUMO energy value of a p-dopant can vary by up to 1 eV depending on the method used to determine the LUMO energy value, specifying the method to use and the full composition of each doped hole transport layer is important make and use the claimed invention. However, neither the method used to measure the LUMO value of the p-dopant, nor the full composition of the claimed HTLs are provided in the instant disclosure.
(C) The state of the prior art
The claims appear to be drawn to a light-emitting device comprising a plurality of HTLs with specific HOMO-LUMO relationships which promote the ability to both block electrons and promote efficient hole transfer to the emitting layer. Devices with cascading LUMO energy levels and devices in which every-other layer has a p-dopant were known as of the filing date of the claimed invention, as set forth below. However, despite these devices being known in the art, the number of p-dopants which are suitable for a light-emitting device is large and the LUMO value of these p-dopants is not an intrinsic value, but rather depends on the environment surrounding the p-dopant, and the method used to measure the LUMO value of the p-dopant. The specification does not reasonably enable a person having ordinary skill in the art to reliably arrive at a device which meets the requirements of the instant claims.
(D) The level of one of ordinary skill
Measuring the HOMO and LUMO energy levels of an organic compound is well-established in the art and various methods exist which are readily accessible to the ordinary skilled artisan with which to complete this task. Whether or not this is within the level of skill of the ordinary skilled artisan is not at debate because it clearly is. However, Examiner’s position is that the LUMO value obtained for a p-dopant can vary significantly depending on which method is used and that Applicant has not made a convincing show that the LUMO values used in the instant disclosure are accurate, nor has Applicant made a convincing show of how any of the other p-dopants described in the specification would fall inside the limitations of the instant claims. Thus, while these values may be simple to obtain and well within the skill of one of ordinary skill in the art, determining the possible LUMO value range for any possible p-dopant, then selecting a first and second p-dopant which have LUMO values that will never overlap under any conditions, presents a serious experimental burden.
(E) The level of predictability in the art
The level of predictability in the LUMO value of a p-dopant is very low. As outlined above, the LUMO energy level value of a p-dopant is not an inherent property and can be influenced by a multitude of factors including environment, method used, and dispersion uniformity.
Additionally, the level of predictability if low because Applicant has only presented data for two p-dopant compounds, HAT-CN and TCNQ, between which the LUMO energy value differ by a mere 0.05 eV. The small size of this difference is important because the measured LUMO value of a p-dopant may differ by up to 1 eV depending on the circumstances surrounding the measurement. In this situation, the predictability is low because the room for error is high.
Examiner also notes that Applicant has not presented any device comparison wherein just the LUMO of one of the p-dopants is different. For example, such a comparison could be made between instant Example 1 and a device comprising the exact same composition except that the second hole transport layer comprises HT3 and HAT-CN. Instead, in the instant specification, the comparison devices all differ from the example devices in both the hole transport compound AND the p-dopant. This means that the observed difference could be the result of changing the hole transport compound instead of being a result of the LUMO relationship between the first and second dopant. In this situation, the predictability is low because more than one independent variable has been changed.
Despite these potential sources of uncertainty, Applicant asserts, “it is determined that, in the light-emitting device according to an embodiment, because the absolute value of the LUMO energy of the second p-dopant compound of the second hole transport layer was greater than the absolute value of the LUMO energy of the first p-dopant compound of the first hole transport layer, it was possible to control the hole injection and transport characteristics, and as a result, the exciton concentration in the emission layer was controlled, thereby improving the device lifespan (paragraph 00355). Examiner finds this assertion unconvincing.
(F) The amount of direction provided by the inventor
Applicant’s Specification contains 3 specific p-dopant examples, in addition to a general formula for α-cyano triaryl[3]radialene derivatives. The asserted LUMO energy level of only 2 of these p-dopants is given and the method used to obtain these LUMO values is not given. Further, based on the data presented in Table 1 of the instant specification, it appears that certain p-dopants are only ever used with a specific hole transport material. For example, HT1 is always paired with HAT-CN and HT3 is always paired with TCNQ. It is unclear if these is a reason for this or what other combinations of p-dopants and hole transport materials are suitable to arrive at the claimed invention. There is not enough direction given to pair the suggest p-dopant compounds with the suggested hole transport compounds in the specification, let alone any p-dopant compound and any hole transport material, as allowed by the independent claims.
(G) The existence of working examples
While applicant’s specification includes 3 specific p-dopant examples, in addition to a general formula for α-cyano triaryl[3]radialene derivatives which may be combined with any of 46 specific hole transport materials or any of a general list of well-established hole transport materials, the HOMO/LUMO level relationships of these compounds is not actually stated nor is any preferred method specified, so it is unclear whether any of the given p-dopant and hole transport compounds actually meet the requirements of the instant independent claim. Further, while applicant has stated the LUMO energy level of two p-dopant compounds in Table 1, for the reasons discussed above, it is not clear whether any combination of the given p-dopants or hole transport compounds, other than the combination of HT1 and HAT-CN, or the combination of HT3 and TCNQ, would be suitable for the claimed invention.
(H) The quantity of experimentation needed to make or use the invention based on the content of the disclosure
The quantity of experimentation needed to make the claimed invention is high because, as outlined above, there is not enough direction provided to arrive at a combination of p-dopants and hole transport materials which could be reasonably expected to have the claimed LUMO energy level relationship, and there is not enough direction provided to arrive at a combination of p-dopants which could be reasonably expected to have the claimed LUMO energy relationship under any circumstances. Moreover, no general formula or structure has been provided to guide the ordinary skilled artisan to a hole transport compound and p-dopant combination which would meet the requirements of the instant claim. Similarly, it is unclear what combination, if any, of p-dopants in the instant specification meet the required LUMO energy level relationship.
As such, independent claim 1 contains subject matter which was not described in the specification in such a way as to enable one skilled in the art to which it pertains, or with which it is most nearly connected, to make and/or use the invention.
Claims 2-20 are rejected by virtue of dependency
Claims 1-20 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Independent claim 1 requires a light-emitting device comprising a plurality of hole transporting layers, of which the first HTL comprises a first hole transporting compound and first p-dopant and the second HTL comprises a second hole transporting compound and a second p-dopant, and the absolute value of the LUMO of the second p-dopant is greater than the absolute values of the LUMO of the first p-dopant. These limitations encompass any conceivable p-dopant and any conceivable hole-transport material in the art of organic light-emitting devices as long as the absolute values of the measured LUMO energy value of the p-dopant in the second hole transport layer is greater than the absolute value of the measured LUMO energy value of the p-dopant in the first hole transport layer.
The instant description only provides two example devices with such a combination that meets this requirement, and both devices have the same hole transport material/p-dopant combination in each respective hole transport layer and the two p-dopants in these example devices have a difference in stated LUMO value which are close enough to be explained by error.
The specification further provides exceptionally broad guidance on hole transport materials and p-dopants that could be used to form more embodiments, but does not give the LUMO value of any of the other p-dopants nor explain how the LUMO values were measured or what conditions would reproduce those values.
Thus, the limited examples described in the written description does not provide a representative number of species sufficient to show that Applicant was in possession of the claimed genus (see MPEP 2163-II-A-3-a-ii).
Claims 2-20 are rejected by virtue of dependency.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-4, 6, 8-11, and 14-19 are rejected under 35 U.S.C. 103 as being unpatentable over Jeon et al. (US 2020/0295095 A1) in view of Lee et al. (US 2014/0183493 A1).
With respect to claim 1, Jeon discloses an organic light emitting device (paragraph 0364 and FIG. 2) comprising a first electrode (210), a second electrode (250), and an interlayer between the electrodes comprising an emission layer (230a) comprising at least one host (paragraph 0228) and a dopant (paragraph 0191), a fourth intermediate layer (instant 3rd hole transport layer, 234, paragraph 0369), a first intermediate layer (instant 2nd HTL, 231), a first auxiliary layer (instant 4th HTL, 230’), and a first layer (instant 1st HTL, 230c) (paragraph 0365), as pictured below.
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Jeon teaches that the intermediate layer (the layers between the electrodes) functions as a hole injection layer (HIL) and HTL, and that at least one of the HIL and HTL may include a p-dopant (paragraph 0178) and a compound of Formula 201 (paragraph 0138, line 9-11), which is a hole-transport compound (paragraph 0035).
Jeon teaches that when the absolute value of the LUMO energy level of each layer in the hole transport region increases with increasing proximity to the emission layer, the blocking of electrons may be further facilitated or improved (paragraph 0120, paragraph 0121 lines 8-13, and paragraph 0370 lines 9-13).
It would have been obvious to a person having ordinary skill in the art prior to the effective filing date of the claimed invention to select p-dopants wherein the absolute value of the LUMO energy level of the dopants increases with increasing proximity to the emission layer in order to facilitate and improve the blocking of electrons, as taught by Jeon.
However, Jeon does not teach nor fairly suggest that the first and second HTLs should contain a p-dopant and the third and fourth HTLs should not.
In analogous art, Lee discloses an organic light-emitting device according to Fig. 1 (paragraph 0026), which is pictured below to facilitate discussion.
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This device comprises a first and second electrode and an interlayer between the electrodes. The interlayer comprises an emission layer (EML), a first hole transport layer (P-HTL), a fourth hole transport layer (HTL, 114b), a second hole transport layer (P-HTL, 114a), and a third hole transport layer (HTL, 114b), in that order, which is the same order as the device of Jeon.
Lee teaches that when two layers of a multi-layered hole transporting layer are formed with a p-dopant, power consumption is reduced and lifespan and efficiency characteristics are improved (paragraph 0113).
It would have been obvious to a person having ordinary skill in the art prior to the effective filing date of the claimed invention to dope the multilayered hole transport region of Jeon in the manner taught by Lee, in alternating layers, in order to obtain reduced power consumption and improved lifespan and efficiency, as taught by Lee.
With respect to claim 2, Jeon and Lee teach the device of claim 1, and Jeon teaches that the device has a hole transport region comprising a hole injection layer, as discussed above.
With respect to claim 3, Jeon and Lee teach the device of claim 1, and Jeon also teaches that the first electrode in an anode, the second electrode is a cathode (paragraph 0363), and the interlayer also comprises an electron transporting region comprising an electron transport layer (paragraph 0277 and 142, FIG. 1).
It would have been obvious to a person having ordinary skill in the art prior to the effective filing date of the claimed invention to use the claimed device structure in the device of Jeon and Lee, as taught by Jeon.
With respect to claim 4, Jeon and Lee teach the device of claim 1, and Jeon also teaches that the device comprises a blue-light emitting layer (paragraph 0407, lines 7-11).
With respect to claim 6, Jeon and Lee teach the device of claim 1, and Jeon also teaches that the first dopant may be a fluorescent dopant (paragraph 0275).
With respect to claim 8, Jeon and Lee teach the device of claim 1, and the second HTL is between the first and third HTL, as pictured and discussed above.
With respect to claim 9, Jeon and Lee teach the device of claim 1, and the first HTL faces the first electrode and the third HTL faces the emission layer, as discussed above.
With respect to claim 10, Jeon and Lee teach the device of claim 1, and Jeon also teaches that the hole transport region may comprise a single material or a plurality of materials (paragraph 0134).
It would have been obvious to a person having ordinary skill in the art prior to the effective filing date of the claimed invention to have the first, second, and third hole transport layers have the same hole transport compound as each other, or have different compounds, as taught by Jeon.
With respect to claim 11, Jeon and Lee teach the device of claim 1, as discussed above.
Jeon also teaches that when the absolute value of the HOMO energy level of each layer in the hole transport region increases with increasing proximity to the emission layer, the injection of holes into the emission layer is facilitated or improved (paragraph 0119, paragraph 0121, lines 1-8, and paragraph 0370, lines 4-9).
It would have been obvious to a person having ordinary skill in the art prior to the effective filing date of the claimed invention to select hole transport compounds wherein the absolute value of the HOMO energy level of the compounds increase with increasing proximity to the emission layer in order to facilitate and improve the injection of holes into the emissive layer, as taught by Jeon.
With respect to claim 14, Jeon and Lee teach the device of claim 1, and the interlayer comprises a fourth HTL between the first HTL and the second HTL, as discussed above.
With respect to claim 15, Jeon and Lee teach the device of claim 14, and the fourth HTL comprises a fourth hole transport compound and does not comprise a p-dopant, as discussed above.
With respect to claim 16, Jeon and Lee teach the device of claim 1, and Jeon also teaches that the interlayer comprises an electron blocking layer (paragraph 0136), and the electron blocking layer may be adjacent to the hole transport layer (paragraph 0136, lines 8-9).
It would have been obvious to a person having ordinary skill in the art prior to the effective filing date of the claimed invention to incorporate an electron blocking layer adjacent to a hole transport layer in the device of Jeon and Lee, as taught by Jeon.
With respect to claim 17, Jeon and Lee teach the device of claim 1, and Jeon also teaches that any HIL may have a thickness of 100 Å to 1,000 Å and any HTL may have a thickness of about 50 Å to 2,000 Å.
In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. 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). Similarly, a prima facie case of obviousness exists where the claimed ranges or amounts do not overlap with the prior art but are merely close. Titanium Metals Corp. of America v. Banner, 778 F.2d 775, 783, 227 USPQ 773, 779 (Fed. Cir. 1985). See MPEP 2144.05 Obviousness of Similar and Overlapping Ranges, Amounts, and Proportions. In the instant case, the claimed range of 10 Å to 500 Å overlaps with the range of the prior art, which is 50 Å to 2,000 Å. Thus, as the ranges overlap, a prima facie case of obviousness is present.
With respect to claims 18 and 19, Jeon and Lee teach the device of claim 1, and Jeon also teaches a flat panel apparatus including a thin-film transistor including a source electrode, a drain electrode, and an active layer, and the light-emitting device is electrically coupled to at least one of the source electrode and the drain electrode of the thing-film transistor (paragraph 0092).
It would have been obvious to a person having ordinary skill in the art prior to the effective filing date of the claimed invention to incorporate the device into an apparatus with the claimed structure, as taught by Jeon.
Claims 5 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Jeon et al. (US 2020/0295095 A1) in view of Lee et al. (US 2014/0183493 A1) as applied above, and further in view of Lee et al. (US 2015/0340618 A1, herein after referred to as Lee 2015).
With respect to claim 5, Jeon and Lee teach the device of claim 1, as discussed above.
However, neither Jeon nor Lee teach nor fairly suggest that the first and/or the second host have both a hole-transporting substituent and an electron-transporting substituent.
In analogous art, Lee 2015 teaches a luminescent material for an organic optoelectronic device (abstract) which has bipolar characteristics as a result of an electron-accepting substituent and a triphenylene group capable of accepting holes as well (paragraph 0021).
Lee 2015 teaches that such a compound is able to appropriately balance the flow of holes and electrons and improve efficiency of an organic optoelectronic device (paragraph 0050) and may be used as a host in the emission layer (paragraph 0161).
It would have been obvious to a person having ordinary skill in the art prior to the effective filing date of the claimed invention to use a bipolar host comprising an electron -transporting substituent and a hole-transporting substituent as the first and/or second host compound in the device of Jeon and Lee in order to appropriately balance the flow of holes and electrons and improve efficiency of an organic optoelectronic device, as taught by Lee 2015.
With respect to claim 20, Jeon and Lee teach the apparatus of claim 18, as discussed above.
However, neither Jeon nor Lee teaches nor fairly suggest a color filter, a color conversion layer, a touch screen layer, a polarizing layer, or any combination thereof.
Lee 2015 teaches that the device may emit white light by laminating colors in a perpendicular direction (paragraph 0048). In this respect, Lee 2015 teaches a color conversion layer in which the primary colors are combined to change the light emitted into white light.
It would have been obvious to a person having ordinary skill in the art prior to the effective filing date of the claimed invention to include a color conversion layer in the device of Jeon and Lee in order to produce white light, as taught by Lee 2015.
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Jeon et al. (US 2020/0295095 A1) in view of Lee et al. (US 2014/0183493 A1) as applied above, and further in view of Wang et al. (US 2017/0256729 A1).
With respect to claim 7, Jeon and Lee teach the device of claim 6, as discussed above.
However, neither Jeon nor Lee teach nor fairly suggest that the fluorescent dopant is a thermally-activated delayed fluorescent (TADF) compound.
In analogous art, Wang discloses a compound for an organic optoelectronic device (abstract) which demonstrates TADF properties and may be used as a TADF material in an organic optoelectronic device as a dopant (paragraph 0119, line 6-8) in order to improve luminous efficiency (paragraph 0120).
It would have been obvious to a person having ordinary skill in the art prior to the effective filing date of the claimed invention to use the TADF compound of Wang as the fluorescent dopant in the emission layer of Jeon and Lee in order to improve luminous efficiency, as taught by Wang.
Claims 12 and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Jeon et al. (US 2020/0295095 A1) in view of Lee et al. (US 2014/0183493 A1) as applied above, and further in view of Sun et al. (US 2020/0350507 A1).
With respect to claims 12 and 13, Jeon and Lee teach the device of claim 1, as discussed above.
However, neither Jeon nor Lee teach that, in the first HTL, the difference between the HOMO energy value of the hole transport compound and LUMO energy value of the corresponding p-dopant compound is less than 0.15 eV.
In analogous art, Sun teaches an organic light-emitting device comprising an organic layer comprising at least a first compound and a second compound, and the difference between the HOMO energy level of the first compound and the LUMO energy level of the second compound is 0.1 eV or more (paragraph 0144, lines 1-5).
Sun teaches that when the difference between the HOMO energy level of the first compound and the LUMO energy level of the second compound is 0.1 eV or more, charge transfer may easily occur therebetween.
In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. 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). Similarly, a prima facie case of obviousness exists where the claimed ranges or amounts do not overlap with the prior art but are merely close. Titanium Metals Corp. of America v. Banner, 778 F.2d 775, 783, 227 USPQ 773, 779 (Fed. Cir. 1985). See MPEP 2144.05 Obviousness of Similar and Overlapping Ranges, Amounts, and Proportions. In the instant case, the prior art teaches 0.1 eV or more, and the instant claims are drawn to a range of less than 0.15 eV. Thus, as the ranges overlap, a prima facie case of obviousness is present, and it would have been obvious to a person having ordinary skill in the art prior to the effective filing date of the claimed invention to select a host and dopant material wherein the HOMO energy level of the hole transporting compound and the LUMO of the p-dopant overlap by less than 0.15 eV in order for charge transfer to easily occur therebetween.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Ha et al. (KR 2017/0134163 A, using the provided translation) – teaches the hole transport compounds used in Example devices 1 and 2 in the instant specification.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to RACHEL SIMBANA whose telephone number is (571)272-2657. The examiner can normally be reached Monday - Friday, 8:00 A.M. - 4:30 P.M..
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/RACHEL SIMBANA/Examiner, Art Unit 1786
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