Cyclohexyl fluorene compounds and uses thereof

Abstract

This application relates to a cyclohexylfluorene compound and its applications. The cyclohexylfluorene compound has the structure shown in general formula (I). As a hole-blocking layer material or an electron transport layer material, this cyclohexylfluorene compound can effectively improve the luminous efficiency, driving voltage, and lifetime of devices.

Description

Technical Field

[0001] This application relates to the field of organic electroluminescence technology, and in particular to a cyclohexylfluorene compound and its applications. Background Technology

[0002] Organic light-emitting diodes (OLEDs) are widely used in mobile phones, flat panel displays, televisions, lighting, and automotive displays due to their advantages such as active light emission, short response time, high color contrast, and low energy consumption. As early as 1963, Pope et al. first discovered the electroluminescence phenomenon of single-crystal anthracene, an organic compound. In 1987, Dr. Ching W. Tang of Kodak reported an OLED fabricated using diaromatic diamine as the hole transport material (HTM) and lithium 8-hydroxyquinoline (Alq3) as both the light-emitting and electron transport materials, achieving a peak brightness of 1000 cd / m². 2 Since then, OLED has developed rapidly and has gradually replaced LCD panels as the next generation of flat panel displays, and it also has great potential in flexible displays.

[0003] The working principle of OLEDs is that holes and electrons injected through electrodes recombine in the light-emitting layer to form excitons, and the excitons emit light through radiative transitions. Typical OLEDs employ a sandwich structure, with an organic layer sandwiched between the anode and cathode. These organic layers are categorized according to their different photoelectric properties, such as hole transport layers, electron transport layers, light-emitting layers, hole blocking layers, and electron blocking layers. However, because most organic electroluminescent materials transport holes faster than electrons, an imbalance in the number of electrons and holes in the light-emitting layer occurs, leading to quenching of light emission and affecting device performance.

[0004] To enable electrons and holes to recombine effectively in the emissive layer to form excitons and emit light, thereby improving device efficiency and lifespan, OLEDs typically employ hole-blocking materials to confine holes within the emissive layer and prevent them from reaching the electron transport layer. Hole-blocking materials should possess low HOMO energy levels, a wide band gap, and suitable electron mobility. Some commonly used hole-blocking materials are organic compounds such as 1,10-o-phenanthroline derivatives (BCP) and 1,3,5-tris(N-phenyl-2-benzimidazole)benzene.

[0005] Fluorene possesses a planar biphenyl structure, exhibiting high molecular rigidity, a high degree of conjugation, high fluorescence quantum efficiency, and thermal stability. It is also easily modified, resulting in excellent electroluminescence performance in OLEDs. Methods exist for applying fluorene-triazine compounds to light-emitting devices, yielding highly efficient OLEDs. Other methods utilize fluorene-triazine compounds as hole-blocking layer materials, improving device efficiency, reducing voltage, and extending device lifespan.

[0006] Although the efficiency and lifespan of OLEDs have been gradually improved, in order to further meet the ever-increasing demand for the photoelectric performance of OLEDs, it is still necessary to explore hole blocking layer materials that are superior in terms of luminous efficiency, driving voltage, and lifespan. Summary of the Invention

[0007] Based on this, this application provides a cyclohexylfluorene compound, which, as a hole blocking layer material or electron transport layer material, can effectively improve the luminous efficiency, driving voltage, and lifetime of the device. This application also provides applications of the said cyclohexylfluorene compound.

[0008] A first aspect of this application provides a cyclohexylfluorene compound having the structure shown in general formula (I):

[0009]

[0010] Wherein, L is a single bond or a biphenylene group;

[0011] Z is either N or CH;

[0012] R1 and R2 are each independently a substituted or unsubstituted C6-C30 aryl group, wherein the substituent on the substituted C6-C30 aryl group includes one or more of deuterium and C1-C5 alkyl groups, and at least one of R1 and R2 is substituted by the substituent.

[0013] In some embodiments of the present invention, Z is N.

[0014] In some embodiments of the present invention, the substituents include C1 to C5 alkyl groups; optionally, the total number of C1 to C5 alkyl groups in R1 and R2 is 1 to 10.

[0015] In some embodiments of the present invention, the total number of deuterium atoms in R1 and R2 is 0 to 10.

[0016] In some embodiments of the present invention, R1 and / or R2, which are replaced by the substituents, are each independently a group that:

[0017]

[0018] In some embodiments of the present invention, L is a biphenylene oxide.

[0019] In some embodiments of the present invention, L is a group that includes:

[0020]

[0021]

[0022] In some embodiments of the present invention, the cyclohexylfluorene compounds have the structures shown in general formulas (I-1) to (I-4):

[0023]

[0024] A second aspect of this application provides the use of the cyclohexylfluorene compounds described in the first aspect as hole blocking layer materials and / or electron transport layer materials.

[0025] A third aspect of this application provides the use of the cyclohexylfluorene compounds described in the first aspect in organic electroluminescent devices, organic solar cells, organic thin-film transistors, organic photodetectors, organic field-effect transistors, organic integrated circuits, or organic photosensors.

[0026] A fourth aspect of this application provides an organic electroluminescent device, comprising a first electrode, a second electrode, and a light-emitting unit disposed between the first electrode and the second electrode, wherein the light-emitting unit comprises at least one of the cyclohexylfluorene compounds described in the first aspect.

[0027] In some embodiments of the present invention, the light-emitting unit includes a hole-blocking layer and an electron transport layer, wherein the hole-blocking layer and / or the electron transport layer comprises at least one of the cyclohexylfluorene compounds described in the first aspect.

[0028] In some embodiments of the present invention, the hole-blocking layer comprises at least one of the cyclohexylfluorene compounds; the electron transport layer comprises a compound having the structure shown in general formula (II):

[0029]

[0030] Among them, R 1 -R 7 Independently represented as hydrogen, deuterium, cyano, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C3-C60 heteroaryl, wherein the substituted substituent includes one or more of deuterium, C1-C5 alkyl, C6-C60 aryl or C3-C60 heteroaryl;

[0031] L 1 and L 2 It is represented as a single bond, a substituted or unsubstituted C6-C60 arylene, a substituted or unsubstituted C3-C60 heteroarylene, wherein the substituted substituent includes one or more of deuterium, C1-C5 alkyl, C6-C60 aryl or C3-C60 heteroaryl;

[0032] Ar 1 and Ar 2Independently represented as substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C3-C60 heteroaryl, wherein the substituted substituent includes one or more of deuterium, C1-C5 alkyl, C6-C60 aryl or C3-C60 heteroaryl;

[0033] Optionally, R 1 -R 7 Independently represented as hydrogen, deuterium, methyl, deuterated methyl, ethyl, phenyl, deuterated benzene, naphthyl, biphenyl, or tolyl;

[0034] Optionally, L 1 and L 2 Represented as a single bond, phenylene, or deuteride-phenylene;

[0035] Optionally, Ar 1 and Ar 2 Independently represented as phenyl, deuterated phenyl, tolyl, biphenyl, naphthyl, phenanthryl, anthracene, perylene, fluoranthyl, pyrene, phenylnaphthyl, naphthylphenyl, diphenylphenyl, 9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, benzyl, 9,9-spirodifluorenyl, benzofuranyl, benzothiophene, dibenzofuranyl, dibenzothiophene, benzo[fluorene-9,9'-oxazanthene], pyridyl, benzylphenyl, pyridylphenyl, indolyl, carbazolylindolyl, fluorenylcarbazolyl, imidazolyl, oxazolyl, thiazolyl, thiadiazolyl, quinolinyl, isoquinolinyl, quinazolinyl, quinoxolinyl, azadibenzofuranyl or azadibenzothiophene;

[0036] Optionally, R 1 -R 7 The total number of deuterium atoms mentioned in the text is 0 to 10.

[0037] A fifth aspect of this application provides a display device, including the organic electroluminescent device described in the third aspect.

[0038] The above-mentioned cyclohexylfluorene compounds, through rational structural design, can achieve the following beneficial effects:

[0039] (1) Because fluorene has good photoelectric properties and thermal stability, it can effectively enhance the thermal stability and glass transition temperature of the compound (e.g., greater than 110℃), which is beneficial to improving the device life.

[0040] (2) As a six-membered ring, the cyclohexyl group has a smaller ring strain and can release the ring strain through a "boat-chair" conformational transition, thus exhibiting better thermodynamic stability compared to alkyl and aryl groups. In addition, its flexibility and conformational variability also make the material more efficient in film formation, resulting in a denser, more uniform, and smoother film, reducing the risk of material blockage during vapor deposition, and improving device efficiency and extending device life.

[0041] (3) The compound has a deep HOMO energy level (e.g., less than -6.2eV). As a hole blocking material, it can effectively block holes in the light-emitting layer from entering the electron transport layer, thereby improving the lifespan and efficiency of the device. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the structure of an organic electroluminescent device in one example of this application.

[0043] In this diagram, 110 represents the glass substrate, 120 represents the anode, 130 represents the hole injection layer, 140 represents the hole transport layer, 150 represents the blocking layer, 160 represents the light-emitting layer, 170 represents the hole blocking layer, 180 represents the electron transport layer, 190 represents the electron injection layer, and 200 represents the cathode. Detailed Implementation

[0044] The following detailed description, in conjunction with specific embodiments, further illustrates the cyclohexylfluorene compounds of this application and their applications. This application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0046] As used herein, the terms “and / or,” “or / and,” and “and / or” may include any one of two or more of the related listed items, as well as any and all combinations of the related listed items, including any two related listed items, any more related listed items, or a combination of all the related listed items.

[0047] In this article, "one or more" refers to any one, two or more of the listed items.

[0048] In this application, terms such as "first aspect," "second aspect," "third aspect," and "fourth aspect" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, terms such as "first," "second," "third," and "fourth" serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on quantity.

[0049] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0050] In this application, numerical ranges are referred to as continuous unless otherwise specified, and include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0051] Unless otherwise specified, the percentage content mentioned in this application refers to mass percentage for solid-liquid mixtures and solid-phase-solid mixtures, and volume percentage for liquid-phase-liquid mixtures.

[0052] Unless otherwise specified, all percentage concentrations mentioned in this application refer to the final concentration. The final concentration refers to the proportion of the added component in the system after the addition of that component.

[0053] Unless otherwise specified, the temperature parameters in this application may be either constant temperature processing or processing within a certain temperature range. The constant temperature processing allows for temperature fluctuations within the precision range controlled by the instrument.

[0054] In this application, room temperature generally refers to 4℃~30℃, and more preferably 20±5℃.

[0055] In this invention, "aryl" refers to an aromatic hydrocarbon group derived from an aromatic ring compound by removing one hydrogen atom. It can be a monocyclic aryl, a fused-ring aryl, or a polycyclic aryl. For polycyclic compounds, at least one must be an aromatic ring system. For example, "C6-C30 aryl" refers to an aryl group containing 6 to 30 carbon atoms. Each occurrence can be independently C5, C6, C7, C8, C9, C10, C12, C14, C18, C20, C25, or C30 aryl. Suitable examples include, but are not limited to, benzene, biphenyl, naphthalene, anthracene, phenanthrene, dinaphthalene, triphenylene, and their derivatives. Understandably, multiple aryl groups can also be interrupted by short non-aromatic units (e.g., <10% non-H atoms, such as C, N, or O atoms), specifically acenaphthene, fluorene, or 9,9-diarylfluorene, triarylamine, and diaryl ether systems should also be included in the definition of aryl.

[0056] In this application, "heteroaryl" refers to an aryl group in which at least one carbon atom is replaced by a non-carbon atom, which can be an N atom, an O atom, an S atom, etc. For example, "C3-C30 heteroaryl" refers to a heteroaryl group containing 3 to 30 carbon atoms, and each occurrence can be independently C3 heteroaryl, C4 heteroaryl, C5 heteroaryl, C6 heteroaryl, C7 heteroaryl, C8 heteroaryl, C9 heteroaryl, C10 heteroaryl, C11 heteroaryl, C12 heteroaryl, C14 heteroaryl, C18 heteroaryl, C20 heteroaryl, C25 heteroaryl, and C30 heteroaryl. Suitable examples include, but are not limited to: furan, benzofuran, thiophene, benzothiophene, pyrrole, pyrazole, triazole, imidazole, oxazole, oxadiazole, thiazole, tetraazole, indole, carbazole, pyrroloimidazole, pyrrolopyrrole, thienopyrrole, thienothiophene, furanolopyrrole, furanolofuran, thienofuran, benzoisoxazole, benzoisothiazolium, benzimazole, pyridine, pyrazine, pyrimidine, triazine, quinoline, isoquinoline, o-diazonyl, quinoxaline, phenanthridine, primidine, quinazoline, and quinazolineone. Understandably, "azaaryl" refers to a heteroaryl group whose non-carbon atom is an nitrogen atom.

[0057] In this application, "alkyl" refers to a monovalent residue formed by the loss of a hydrogen atom from a saturated hydrocarbon containing a primary (normal) carbon atom, a secondary carbon atom, a tertiary carbon atom, a quaternary carbon atom, or a combination thereof. Phrases containing this term, such as "C1-C5 alkyl," refer to alkyl groups containing 1 to 5 carbon atoms, and each occurrence can be independently referred to as C1 alkyl, C2 alkyl, C3 alkyl, C4 alkyl, or C5 alkyl. Suitable examples include, but are not limited to: methyl (Me, -CH3), ethyl (Et, -CH2CH3), 1-propyl (n-Pr, n-propyl, -CH2CH2CH3), 2-propyl (i-Pr, i-propyl, -CH(CH3)2), 1-butyl (n-Bu, n-butyl, -CH2CH2CH2CH3), 2-methyl-1-propyl (i-Bu, i-butyl, -CH2CH(CH3)2), 2-butyl (s-Bu, s-butyl, -CH(CH3)CH2CH3), 2-methyl-2-propyl (t- Bu, t-butyl, -C(CH3)3), 1-pentyl (n-pentyl, -CH2CH2CH2CH2CH3), 2-pentyl (-CH(CH3)CH2CH2CH3), 3-pentyl (-CH(CH2CH3)2), 2-methyl-2-butyl (-C(CH3)2CH2CH3), 3-methyl-2-butyl (-CH(CH3)CH(CH3)2), 3-methyl-1-butyl (-CH2CH2CH(CH3)2), 2-methyl-1-butyl (-CH2CH(CH3)CH2CH3).

[0058] In this application, *Refers to the part that is joined, *refers to the part that is fused or joined.

[0059] Some examples of this application provide a cyclohexylfluorene compound having the structure shown in general formula (I):

[0060]

[0061] Wherein, L is a single bond or a biphenylene group;

[0062] Z is either N or CH;

[0063] R1 and R2 are each independently a substituted or unsubstituted C6-C30 aryl group, wherein the substituents on the C6-C30 aryl group include one or more of deuterium and C1-C5 alkyl groups, and at least one of R1 and R2 is substituted by the substituent.

[0064] In some embodiments of the present invention, Z is N. When Z is N, it is a triazine group. Since the triazine group has strong electronegativity and high electron mobility, it can effectively improve electron transport and electron injection, enhance the charge transport capability of the material, and reduce the operating voltage of the device.

[0065] In some embodiments of the present invention, the substituents include C1-C5 alkyl groups. Introducing C6-C30 aryl groups substituted with C1-C5 alkyl groups as R1 and R2 can reduce the conjugation of the compound, lower its HOMO energy level, and, as a hole-blocking layer material, more effectively block holes from entering the electron transport layer, confining holes within the hole transport layer, thereby improving the current efficiency of the organic electroluminescent device and extending its lifetime. The more C1-C5 alkyl groups present, the longer the device lifetime is extended.

[0066] Furthermore, the total number of C1 to C5 alkyl groups in R1 and R2 is 1 to 10. Specifically, the total number of C1 to C5 alkyl groups is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10.

[0067] Furthermore, introducing a 2-tolyl or 3-tolyl group as R1 and R2. Even further, using sterically hindered substituents (such as 2,6-dimethylbenzene) as R1 and R2 will result in a better extension of device lifetime.

[0068] In the above structure, the C1-C5 alkyl substituents in R1 and R2 are an important means of structural regulation. They significantly affect the electronic energy level structure of the material by increasing the steric hindrance of the molecule, thereby significantly impacting device performance. Furthermore, the introduction of C1-C5 alkyl substituents can alter the molecular structure and electron cloud distribution of the material, thus affecting the band structure and electron transport performance. Appropriate methyl substitution can regulate the band structure and charge balance, increasing the triplet energy level of the material, and thus improving the current efficiency of the device. Understandably, in OLED devices, current efficiency refers to the luminous intensity produced per unit current. The improvement of current efficiency is closely related to the energy level structure of the material. In OLED materials, the electronic energy levels of molecules can be divided into the ground state (S0) and excited states (S1, T1, etc.). The S1 state is the lowest energy level among the excited states, while the T1 state is the lowest energy level among the triplet states. The introduction of C1-C5 alkyl substituents can increase the steric hindrance of the molecular structure, making the internal space of the molecule more crowded. This crowding effect leads to an increase in the energy levels of the S1 and T1 states, thereby improving the current efficiency of the material. This is because, in OLED devices, the energy level structure of the excited state determines the efficiency of carrier (electron and hole) injection into the luminescent material to form excitons. Once excitons are formed, they can emit light through spontaneous emission. Therefore, increasing the triplet energy level of the material can enhance the efficiency of carrier injection and exciton formation, thereby improving the current efficiency of the device.

[0069] Furthermore, increasing the number of C1-C5 alkyl groups does not necessarily lead to a linear increase in current efficiency. As the number of C1-C5 alkyl groups increases, the steric hindrance effect within the molecule intensifies, resulting in a gradual weakening of the energy level modulation effect. Generally, increasing the number of C1-C5 alkyl groups also leads to an increase in the driving voltage of OLED devices because these alkyl groups introduce additional electronic barriers, hindering charge injection and transport. Therefore, when selecting and designing OLED materials, it is necessary to comprehensively consider the amount of C1-C5 alkyl groups introduced to achieve optimal current efficiency.

[0070] In some embodiments of the present invention, one or two 2-methylbenzene or 3-methylbenzene groups may be attached to the triazine group. Without limitation, the position of the methyl group may be selected as follows:

[0071]

[0072] In some embodiments of the present invention, the substituents include deuterium. Introducing deuterium-substituted C6-C30 aryl groups as R1 and R2 can reduce vibrational energy loss in the compound, improve exciton-to-photon conversion efficiency, enhance device luminous efficiency, and extend device lifetime. The higher the number of deuterium substitutions (the higher the deuteration rate), the longer the lifetime of the compound-based device. Deuteration can also modulate the band structure and electron affinity of the material. By introducing deuteration into the compound, the spatial distribution and electron cloud density of the molecule can be altered, thereby modulating the compound's band structure and electron affinity, and consequently affecting the luminous efficiency and color purity of the OLED device. Deuteration can also interact with other groups, optimizing the overall performance of the material through interactions such as covalent bonds or hydrogen bonds. The correlation between deuteration and other groups can improve the compound's performance, increasing device efficiency and lifetime by adjusting the molecular structure. For example, the substitution of one or more hydrogen atoms on a phenyl group with deuterium to form a deuterated phenyl group can improve the solubility, thermal stability, and electron affinity of the material; the substitution of one or more hydrogen atoms on a methyl group with deuterium to form a deuterated methyl group (-CD3) can increase the photostability of the compound because carbon-deuterium bonds are more stable than carbon-hydrogen bonds; deuterated aza aromatic rings (such as pyridine, pyrimidine, triazine, etc.) are important for the formation of highly efficient host material compounds in certain situations, and deuterated aza aromatics may further improve their performance; deuteration of oxygen-containing groups: for example, deuterated alcohol groups (-OD), deuterated ketone groups (-CO-D), or deuterated ether groups (-OD), such combinations can help adjust the optical properties, electron transfer capabilities, and stability of the compound.

[0073] Furthermore, the total number of deuterium atoms in R1 and R2 is 0 to 10. Specifically, the total number of deuterium atoms is 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10.

[0074] In the above structure, introducing deuteration into R1 and R2 can increase the electron transport performance and lifetime of the material. In some embodiments of the present invention, R1 and R2 are deuterated phenyl groups, with the deuteration substitution positions preferably at the para and meta positions of benzene, and the deuteration substitution rate can be selected from 20% to 100%. Introducing deuteration into R1 and R2 can adjust the electronic structure and fluorescence properties of the material. Deuteration substitution at different positions may change the hole transport performance, fluorescence spectrum, and charge injection efficiency of the material, and may also affect the solubility and thin film morphology of the material, thereby affecting the processability and performance stability of the device. The deuteration substitution rate also affects the performance of the material. Moderate deuteration substitution can enhance the stability and durability of the material and reduce degradation and loss. However, excessive deuteration substitution may lead to a decrease in the electron transport performance and luminescence efficiency of the material. Increasing the number of deuterations will also increase the complexity and cost of the material. Therefore, performance requirements and cost-effectiveness should be comprehensively considered when selecting the number of deuterations.

[0075] Without limitation, the structure of a deuterated phenyl group can be as follows:

[0076] Low-degree deuterated phenyl groups: These materials have a lower number of deuterated atoms, typically between 20% and 40%. They exhibit high luminous efficiency, low electron transport impedance, and fast electron mobility, and are generally used to fabricate organic electroluminescent devices with high luminous efficiency and low driving voltage. The deuteration position can be para- or meta-position, with the following possible structures:

[0077]

[0078] Moderately deuterated phenyl groups: With a moderate number of deuterated atoms, typically between 40% and 80%, these materials exhibit better thermal stability and higher photoelectric conversion efficiency. They also have a higher glass transition temperature and an increased triplet energy level (T1), making them suitable for high-temperature resistant and long-lived organic electroluminescent devices. The deuteration position can be either para- or meta-positions, resulting in the following possible structures:

[0079]

[0080] Highly deuterated phenyl groups: These materials have a high number of deuterated atoms, typically between 80% and 100%. They exhibit excellent thermal stability, lower charge transport losses, and longer lifetimes. The glass transition temperature is also higher because deuteration enhances the stability of internal molecular bonds, reducing the rate of thermal decomposition and thus improving thermal stability. The triplet energy level (T1) is higher because the heavier deuterium, by substituting hydrogen atoms in the phenyl group, lowers the vibrational frequency of the molecule, thereby lowering the excited state energy level. A high triplet energy level improves luminous efficiency and extends lifetime. Similarly, deuteration reduces internal molecular vibrations and resonance transfers, thus reducing the degradation rate and extending the material's lifetime. They are generally used in organic electroluminescent devices requiring high temperatures and long luminous lifetimes. When there is only one deuterated phenyl group on the fluorene or triazine, the deuteration substitution rate can be 100%. However, when there are multiple deuterated phenyl groups on the fluorene or triazine (greater than or equal to two), the deuteration substitution rate for a single phenyl group can be selected from 20% to 80%.

[0081]

[0082] Deuterated methyl groups are formed by replacing hydrogen atoms (H) in the methyl group with deuterium atoms (D), resulting in the -CD3 group in the compound. Deuterium atoms are heavier than hydrogen atoms, which gives molecules containing deuterated methyl groups higher thermal and chemical stability. Simultaneously, the carbon-deuterium bond is more stable than the carbon-hydrogen bond, increasing the compound's photostability. Due to the higher bond energy between deuterium and carbon, this compound is more resistant to changes in the external environment (such as light and temperature), contributing to a longer lifespan for OLED devices. Furthermore, deuterated methyl groups can improve fluorescence quantum efficiency by reducing the nonradiative triplet state level, thereby achieving better luminous efficiency and color purity. The optional structures of deuterated methyl groups are as follows:

[0083]

[0084] Understandably, the deuteration rate refers to the ratio of deuterium to hydrogen in a deuterated phenyl group. Choosing a suitable deuteration rate can be adjusted according to target performance and application requirements. Generally, a higher deuteration rate can enhance the effect of the substituent, having a more significant impact on the electron transport properties and band structure of the material. However, a higher deuteration rate may also lead to increased synthesis difficulty and higher costs. Therefore, a suitable deuteration rate needs to be selected based on a comprehensive consideration of factors such as performance, synthesis difficulty, and economics. The deuteration rate of the deuterated phenyl group in this application ranges from 10% to 100%. Specifically, the deuteration rates are 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 100%.

[0085] In some embodiments of the present invention, R1 and / or R2, which are replaced by the substituents, are each independently a group that:

[0086]

[0087] In some embodiments of the present invention, L is a biphenylene oxide.

[0088] Understandably, there are several options for the substitution positions of the two groups on L. First, symmetrical positions can be considered, where the two groups substitute on different benzene rings of the biphenylene group. Symmetrical substitution positions help maintain the spatial symmetry of the material, facilitating the formation of a stable molecular structure and thus improving the material's thermal stability and optical properties. Second, the spatial electron cloud distribution should be considered. Different substitution positions on the biphenylene group affect the interaction between the substituents and the surrounding chemical environment. These interactions influence the electron cloud distribution and conjugation effect within the biphenylene group, thereby affecting the material's band structure and electron transport properties. Specifically, different substitution positions may cause differences in the electron density distribution within the biphenylene group, thus affecting the material's electron transport properties and carrier mobility. Finally, the conjugation effect should be considered. The conjugation effect within the biphenylene group has a significant impact on the material's photoelectric properties and fluorescence efficiency. The choice and position of the substituents can adjust the conjugation length and degree within the biphenylene group, thus affecting the material's band structure and fluorescence properties. Generally, a longer conjugation length and a higher degree of conjugation contribute to improved photoelectric properties and luminescence efficiency.

[0089] In some embodiments of the present invention, L is a group that includes:

[0090]

[0091]

[0092] In some embodiments of the present invention, the cyclohexylfluorene compounds have the structures shown in general formulas (I-1) to (I-4):

[0093] as well as

[0094]

[0095] Without limitation, the cyclohexylfluorene compound may be any one of the following compounds:

[0096]

[0097]

[0098]

[0099] Other examples of this application provide the application of the cyclohexylfluorene compounds as hole blocking layer materials and / or electron transport layer materials.

[0100] Other examples of this application provide the application of the described cyclohexylfluorene compounds in organic electroluminescent devices, organic solar cells, organic thin-film transistors, organic photodetectors, organic field-effect transistors, organic integrated circuits, or organic photosensors.

[0101] Other examples of this application provide an organic electroluminescent device, including a first electrode, a second electrode, and a light-emitting unit disposed between the first electrode and the second electrode, wherein the light-emitting unit comprises at least one of the cyclohexylfluorene compounds as described above.

[0102] In some embodiments of the present invention, the light-emitting unit includes a hole-blocking layer and an electron transport layer, wherein the hole-blocking layer and / or the electron transport layer comprises at least one of the cyclohexylfluorene compounds as described above.

[0103] Without limitation, when the electron transport layer contains at least one of the cyclohexylfluorene compounds as described above, it may be doped with an organometallic complex, such as lithium 8-hydroxyquinoline (Liq), wherein the doping mass content of the organometallic complex is 20-70 wt%.

[0104] In some embodiments of the present invention, the hole-blocking layer comprises at least one of the cyclohexylfluorene compounds; the electron transport layer comprises a compound having the structure shown in general formula (II):

[0105]

[0106] Among them, R 1 -R 7 Independently represented as hydrogen, deuterium, cyano, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C3-C60 heteroaryl, wherein the substituted substituent includes one or more of deuterium, C1-C5 alkyl, C6-C60 aryl or C3-C60 heteroaryl;

[0107] L 1 and L 2 It is represented as a single bond, a substituted or unsubstituted C6-C60 arylene, a substituted or unsubstituted C3-C60 heteroarylene, wherein the substituted substituent includes one or more of deuterium, C1-C5 alkyl, C6-C60 aryl or C3-C60 heteroaryl;

[0108] Ar 1 and Ar 2 Independently represented as a substituted or unsubstituted C6-C60 aryl, a substituted or unsubstituted C3-C60 heteroaryl, wherein the substituted substituent includes one or more of deuterium, C1-C5 alkyl, C6-C60 aryl or C3-C60 heteroaryl;

[0109] In some embodiments of the present invention, R 1 -R 7 Independently represented as hydrogen, deuterium, methyl, deuterated methyl, ethyl, phenyl, deuterated benzene, naphthyl, biphenyl, or tolyl.

[0110] In some embodiments of the present invention, L 1 and L 2 It is represented as a single bond, phenylene, or deuterated phenylene.

[0111] In some embodiments of the present invention, Ar 1 and Ar 2 Independently represented as phenyl, deuterated phenyl, tolyl, biphenyl, naphthyl, phenanthryl, anthracene, perylene, fluoranthracene, pyrene, phenylnaphthyl, naphthylphenyl, diphenylphenyl, 9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, benzyl, 9,9-spirodifluorenyl, benzofuranyl, benzothiophene, dibenzofuranyl, dibenzothiophene, spiro[fluorene-9,9'-oxazanthracene], pyridyl, benzylphenyl, pyridylphenyl, indolyl, carbazolylindolyl, fluorenylcarbazolyl, imidazolyl, oxazolyl, thiazolyl, thiadiazolyl, quinolinyl, isoquinolinyl, quinazolinyl, quinoxolinyl, azadibenzofuranyl or azadibenzothiophene.

[0112] In some embodiments of the present invention, R 1 -R 7 The total number of deuterium atoms mentioned herein is 0 to 10. Specifically, the total number of deuterium atoms is 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10.

[0113] Furthermore, the introduction of cyano groups on the benzene ring can alter the thermal stability and electron transport properties of the material, affecting the lifespan of OLED devices. Appropriate cyano substitution can improve the thermal stability and electron transport properties of the material, thereby extending the lifespan of OLED devices.

[0114] The cyano substitution position on the benzene ring has a significant impact on the driving voltage. Generally, para-substitution introduces a larger electronic barrier, resulting in a higher driving voltage. Ortho- and meta-substitution introduce smaller electronic barriers, leading to lower driving voltages. The substitution position also significantly affects the conjugation effect and electron transport properties of the material. Generally, para-substitution causes a large conjugation disruption, affecting charge transport and luminous efficiency. Ortho- and meta-substitution maintain better conjugation, which is beneficial for improving the efficiency of OLED devices. The substitution position also affects the thermal stability and electron transport properties of the material. Para-substitution may cause larger torsional strain and changes in band structure, thus affecting the thermal stability and lifetime of the material. Ortho- and meta-substitution maintain better molecular structural stability and electron transport properties, which is beneficial for improving the lifetime of OLED devices. The cyano position can be selected as follows:

[0115]

[0116] Pyridine linked to the triazine group can improve the electron transport performance of the material. The substitution position of the nitrogen atom in the pyridine group has a significant impact on the driving voltage of OLED devices. Para-substitution introduces a larger electronic barrier, resulting in a higher driving voltage. Ortho- and meta-substitution introduce smaller electronic barriers, resulting in a lower driving voltage. The substitution position also affects the efficiency of OLED devices. Para-substitution may cause deformation of the molecular structure, leading to changes in band structure and conjugation interruption, thereby reducing charge transport efficiency. Ortho- and meta-substitution usually maintain better molecular structural stability and conjugation, which is beneficial to improving the efficiency of OLED devices. The substitution position also has a certain impact on the lifetime of OLED devices. Para-substitution may introduce larger molecular distortion strain, leading to molecular structural instability and changes in band structure, thus affecting the thermal stability and lifetime of the material. Ortho- and meta-substitution usually maintain better molecular structural stability and electron transport performance, which is beneficial to improving the lifetime of OLED devices. The pyridine substitution positions can be selected as follows:

[0117]

[0118] Without limitation, a compound having the structure shown in general formula (II) can be any of the following compounds:

[0119]

[0120]

[0121]

[0122] Without limitation, the electron transport layer may also be doped with organometallic complexes, such as lithium 8-hydroxyquinoline, wherein the doping mass content of the organometallic complex is 20wt% to 70wt%.

[0123] Without limitation, the light-emitting unit further includes a light-emitting layer, the range of visible light of which can be adjusted as needed. Further, the light-emitting layer may contain compounds including, but not limited to, naphthalene compounds, pyrene compounds, fluorene compounds, phenanthrene compounds, chrysene compounds, fluoranthene compounds, anthracene compounds, pentanebenzene compounds, perylene compounds, diarylethene compounds, triphenylamine ethylene compounds, amine compounds, carbazole compounds, benzimidazole compounds, furan compounds, organometallic fluorescent complexes, organometallic phosphorescent complexes (such as Ir, Pt, Os, Cu, Au), boron nitrogen compounds, polyvinylcarbazole, polyorganosilicon compounds, polythiophene, and other organic polymeric light-emitting materials. These can be used alone or in mixtures.

[0124] Without limitation, the light-emitting unit comprises at least one of a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer.

[0125] Without limitation, the total thickness of the light-emitting unit is 1 nm to 1000 nm. Further, the total thickness of the light-emitting unit is 50 nm to 500 nm.

[0126] Without limitation, each layer in the light-emitting unit of the organic electroluminescent device can be prepared by vacuum evaporation, molecular beam evaporation, solvent-based dip coating, spin coating, rod coating, or inkjet printing. The first electrode and the second electrode are metal electrodes and can be prepared by evaporation or sputtering.

[0127] Other examples of this application also provide a display device, including the organic electroluminescent device described above.

[0128] For experimental parameters not specified in the following specific embodiments, please refer to the guidelines given in this application document first, or refer to experimental manuals or other experimental methods known in the art, or refer to the experimental conditions recommended by the manufacturer.

[0129] The raw materials and reagents involved in the following specific embodiments can be obtained commercially or prepared by those skilled in the art using known methods. Examples 1 to 6 below are methods for synthesizing some intermediates and / or compounds of this application. The synthesized intermediates or products were separated by column chromatography and then analyzed by nuclear magnetic resonance mass spectrometry (NMR mass spectrometry). 1 HNMR), high-resolution mass spectrometry (HNMR), 1 Molecular structure characterization was performed using HRMS.

[0130] Example 1

[0131]

[0132] Synthesis of intermediate 1-1

[0133] 2-Bromospiro[cyclohexyl-1,9'-fluorene] (10.0 g, 31.92 mmol), m-chlorophenylboronic acid (5.5 g, 35.17 mmol), and potassium carbonate (6.6 g, 47.75 mmol) were added to a three-necked flask, followed by toluene (60 mL), ethanol (30 mL), and deionized water (30 mL). Under nitrogen protection, di(triphenylphosphine)palladium chloride (Pd(PPh3)2Cl2, 0.2 g, 0.28 mmol) was added, and the mixture was refluxed for 5 h. After the reaction was completed, the mixture was separated, the organic phase was concentrated to dryness, and the crude product was separated by column chromatography to obtain 9.5 g of oily liquid, with a yield of 86%.

[0134] HRMS(ESI, m / z): [M] + calcd for: C 24 H 21 Cl, 344.1332, found, 344.1335.

[0135] Synthesis of intermediates 1-2

[0136] Intermediate 1-1 (9.0 g, 26.10 mmol), pinacol diborate (8.0 g, 31.50 mmol), potassium acetate (7.7 g, 78.46 mmol), and anhydrous toluene (90 mL) were placed in a three-necked flask. Under nitrogen protection, diphenylphosphine palladium chloride (Pd(PPh3)2Cl2, 0.18 g, 0.26 mmol) was added, and the mixture was refluxed for 5 h. The mixture was filtered, concentrated to dryness, and separated by column chromatography to give a white solid of 10.2 g, with a yield of 89%.

[0137] HRMS(ESI, m / z): [M+H] + calcd for: C 30 H 34 BO2, 437.2646, found, 437.2643.

[0138] Synthesis of intermediates 1-3

[0139] 2-Chloro-4-(3-chlorophenyl)-6-phenyl-1,3,5-triazine (10.0 g, 33.10 mmol), phenylboronic acid-d5 (4.6 g, 36.23 mmol), and potassium carbonate (6.9 g, 49.92 mmol) were added to a three-necked flask, followed by toluene (60 mL), tetrahydrofuran (30 mL), and deionized water (30 mL). Under nitrogen protection, di(triphenylphosphine)palladium chloride (Pd(PPh3)2Cl2, 0.2 g, 0.28 mmol) was added, and the mixture was refluxed for 5 h. After the reaction was complete, the mixture was separated into liquid and liquid phases, concentrated to dryness, and separated by column chromatography to obtain a white solid at 10.1 g, with a yield of 87%.

[0140] HRMS(ESI, m / z): [M+H] + calcd for: C 21 H9D5ClN3, 348.1190, found, 348.1195.

[0141] Synthesis of Compound 1

[0142] Intermediate 1-3 (1 g, 2.87 mmol), intermediate 1-2 (1.31 g, 3.00 mmol), and potassium carbonate (0.6 g, 4.34 mmol) were added to a three-necked flask, followed by toluene (10 mL), tetrahydrofuran (5 mL), and deionized water (5 mL). Under nitrogen protection, diphenylphosphine palladium chloride (0.01 g, 0.014 mmol) was added. After reflux for 10 h, a solid precipitated, which was filtered, washed with ethanol, and separated by column chromatography with PE / DCM = 1 / 2 elution. The solid was concentrated to dryness and dried to give 1.36 g of white solid, with a yield of 76%.

[0143] 1 H NMR (400MHz, CDCl3) δ: 8.18-8.23(m,3H),8.11-8.13(m,1H),7.81-7.82(m,1H),7.57-7.71(m,3H),7.31-7.5 3(m,11H),7.16-7.18(m,1H),2.16-2.29(m,4H),1.62-1.74(m,4H),1.44-1.51(m,2H).HRMS(ESI,m / z):[M+H] + calcd for:C 45 H 31 D5N3,623.3218,found,623.3219.Anal.:calcd:C,86.78;H,6.47;N,6.75;found:C,86.85;H,6.40;N,6.73.

[0144] Example 2

[0145]

[0146] Synthesis of intermediate 2-1

[0147] The synthesis method is the same as that for intermediates 1-3, with a yield of 65%.

[0148] HRMS(ESI, m / z): [M+H] + calcd for: C 21 H5D 10 ClN3, 355.1577, found, 354.1578.

[0149] Synthesis of Compound 2

[0150] The synthesis method is the same as that for compound 1, with a yield of 69%.

[0151] 1 H NMR (400MHz, CDCl3) δ: 8.18-8.22(m,2H),7.81-7.82(m,1H),7.63-7.71(m,2H),7.57-7.60(m,1H),7.44-7 .53(m,5H),7.31-7.38(m,3H),7.16-7.18(m,1H),2.16-2.29(m,4H),1.62-1.74(m,4H),1.44-1.51(m,2H). HRMS(ESI,m / z):[M+H] + calcd for:C 45 H 26 D 10 N3,628.3531,found,628.3529.Anal.:calcd:C,86.09;H,7.22;N,6.69;found:C,85.98;H,7.27;N,6.75.

[0152] Example 3

[0153]

[0154] Synthesis of intermediate 11-1

[0155] The synthesis method is the same as that for intermediate 1-1, with a yield of 89%.

[0156] HRMS(ESI, m / z): [M] + calcd for: C 24 H 21 Cl, 344.1332, found, 344.1329.

[0157] Synthesis of intermediate 11-2

[0158] The synthesis method is the same as that for intermediates 1-2, with a yield of 92%.

[0159] HRMS(ESI, m / z): [M+H] + calcd for: C 30 H 34 BO2, 437.2646, found, 437.2642.

[0160] Synthesis of Compound 11

[0161] The synthesis method is the same as that for compound 1, with a yield of 68%.

[0162] 1 H NMR (400MHz, CDCl3) δ: 8.18-8.23(m,3H),8.11-8.13(m,1H),7.94-7.96(m,1H),7.63-7.73(m,2H) ,7.32-7.57(m,11H),7.12-7.18(m,2H),2.17-2.29(m,4H),1.64-1.74(m,4H),1.44-1.51(m,2H). HRMS(ESI,m / z):[M+H] + calcd for:C 45 H 31 D5N3,623.3218,found,623.3223.Anal.:calcd:C,86.78;H,6.47;N,6.75;found:C,86.65;H,6.58;N,6.84.

[0163] Example 4

[0164]

[0165] Synthesis of intermediate 15-1

[0166] The synthesis method is the same as that for intermediates 1-3, with a yield of 73%.

[0167] HRMS(ESI,m / z):[M+H] + calcd for:C 23 H 19 ClN3,372.1262,found,372.1258.

[0168] Synthesis of Compound 15

[0169] The synthesis method is the same as that for compound 1, with a yield of 78%.

[0170] 1 H NMR(400MHz, CDCl3)δ:8.16-8.24(m,4H),7.80-7.83(m,2H),7.67-7.71(m,2H),7.57-7.60(m,1H),7.29-7.53(m,12H),7 .25-7.26(m,1H),7.16-7.18(m,1H),2.50(s,3H),2.32(s,3H),2.16-2.29(m,4H),1.64-1.74(m,4H),1.44-1.51(m,2H). HRMS(ESI,m / z):[M+H] + calcd for:C 47 H 40 N3,646.3217,found,646.3220.Anal.:calcd:C,87.41;H,6.09;N,6.51;found:C,87.49;H,6.04;N,6.44.

[0171] Example 5

[0172]

[0173] Synthesis of intermediate 16-1

[0174] The synthesis method is the same as that for intermediates 1-3, with a yield of 74%.

[0175] HRMS(ESI,m / z):[M+H] + calcd for:C 21 H 23 ClN3,400.1575,found,400.1578.

[0176] Synthesis of Compound 16

[0177] The synthesis method is the same as that for compound 1, with a yield of 78%.

[0178] 1H NMR(400MHz, CDCl3)δ:8.18-8.26(m,2H),7.81-7.84(m,3H),7.67-7.71(m,2H),7.57-7.60(m,1H),7.45-7.52(m,5H),7.29-7.37 (m,5H),7.24-7.27(m,2H),7.16-7.18(m,1H),2.50(s,6H),2.32(s,6H),2.15-2.27(m,4H),1.63-1.74(m,4H),1.44-1.51(m,2H). HRMS(ESI,m / z):[M+H] + calcd for:C 49 H 44 N3,674.3530,found,674.3535.Anal.:calcd:C,87.33;H,6.43;N,6.24;found:C,87.21;H,6.52;N,6.31.

[0179] Example 6

[0180]

[0181] Synthesis of intermediate 21-1

[0182] The synthesis method is the same as that for intermediates 1-3, with a yield of 65%.

[0183] HRMS(ESI,m / z):[M+H] + calcd for:C 24 H 21 ClN3,386.1419,found,386.1422.

[0184] Synthesis of Compound 15

[0185] The synthesis method is the same as that for compound 1, with a yield of 82%.

[0186] 1 H NMR(400MHz, CDCl3)δ:8.16-8.25(m,4H),7.81-7.82(m,1H),7.67-7.71(m,2H),7.57-7.60(m,1H),7.31-7.60( m,11H),7.15-7.18(m,3H),2.42(s,6H),2.30(s,3H),2.16-2.29(m,4H),1.64-1.74(m,4H),1.44-1.51(m,2H). HRMS(ESI,m / z):[M+H] + calcd for:C48 H 42 N3,660.3373,found,660.3370.Anal.:calcd:C,87.37;H,6.26;N,6.37;found:C,87.28;H,6.36;N,6.33.

[0187] Device Examples

[0188] The structure and performance of organic electroluminescent devices prepared using the compounds of this application are further described in detail below through Examples 7 to 16 and Comparative Examples 1 to 6.

[0189] The examples and comparative examples demonstrate the fabrication of organic electroluminescent devices using the aforementioned compounds, and their structural schematic diagrams are shown below. Figure 1 It includes a glass substrate 110, an anode 120, a hole injection layer 130, a hole transport layer 140, a blocking layer 150, a light-emitting layer 160, a hole blocking layer 170, an electron transport layer 180, an electron injection layer 190, and a cathode 200, stacked sequentially. The specific structure is: glass / anode (ITO) / hole injection layer (HIL) / hole transport layer (HTL) / electron blocking layer (EBL) / light-emitting layer (EML, main material: blue light-emitting material) / hole blocking layer (HBL) / electron transport layer (ETL, electron transport material: lithium 8-hydroxyquinoline) / electron injection layer (EIL) / cathode.

[0190] Example 7

[0191] A transparent conductive ITO glass substrate 110 (with an anode 120) (China Southern Glass Holding Co., Ltd.) was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, and then sequentially washed with ethanol, acetone, and deionized water. It was then baked in a clean environment until all moisture was removed, cleaned with ultraviolet photosynthetic ozone, and treated with oxygen plasma for 30 seconds. The anode-bearing glass substrate was then placed in a vacuum chamber and evacuated.

[0192] Hole injection layer: HIL (5nm) was deposited on ITO as hole injection layer 130 at a deposition rate of 0.1nm / s.

[0193] Hole transport layer: Compound HT is deposited on the hole injection layer to form a 100 nm thick hole transport layer 140, with a deposition rate of 0.1 nm / s.

[0194] Electron blocking layer: EB was deposited by vapor deposition to form a 10 nm thick electron blocking layer 150. The deposition rate was 0.1 nm / s.

[0195] Light-emitting layer: A 30nm thick light-emitting layer 160 is deposited on the electron blocking layer, wherein BH is the host light-emitting material and BD is used as the phosphorescent dopant material at a weight ratio of 3%, and the deposition rate is 0.1nm / s.

[0196] Hole blocking layer: Compound 1 is deposited on the light-emitting layer to form a 5 nm thick hole blocking layer 170, with a deposition rate of 0.1 nm / s.

[0197] Electron transport layer: A 35 nm thick ET1:Liq (weight ratio 5:5) was deposited as the electron transport layer 180, where Liq is lithium 8-hydroxyquinoline. The deposition rate was 0.1 nm / s.

[0198] Electron injection layer: 1nm Liq vapor-deposited as electron injection layer 190.

[0199] Cathode: 120nm Al is used as the cathode of the device 200.

[0200] Examples 8-16 and Comparative Examples 1-8

[0201] The fabrication method of the device is the same as that of Example 7, except that the materials used for the electron transport layer and hole blocking layer in the device are different. The specific electronic materials used in each example and comparative example are shown in Table 1.

[0202] The structural formula described in the device is as follows:

[0203]

[0204]

[0205] Table 1 Device Structure

[0206]

[0207]

[0208] The following examples demonstrate the performance testing of the devices prepared in this application, further illustrating the beneficial technical effects of the compound containing general formula I as an organic electronic material.

[0209] (1) Testing of device performance

[0210] Device performance was tested using a Photo Research PR655 spectrometer, and measurements were taken at 1000 cd / cm². 2 Operating voltage, efficiency, and emission wavelength at various brightness levels. Room temperature and high temperature lifetime tests were conducted using a Jinghe D3000-96CH lifetime meter, measured at 12 mA / cm². 2The time (T90) for the brightness to become 90% of the initial brightness in environments with normal temperature (27℃) and high temperature (85℃) under current density is shown in Table 2. The device performance parameters and test results are shown in Table 2.

[0211] Table 2 Device Performance Parameters

[0212]

[0213] (2) Glass transition temperature of the compound

[0214] The glass transition temperature (Tg) of the compound was tested using a Pyris Diamond (DSC2920) differential scanning calorimeter under nitrogen protection at a heating and cooling rate of 10 °C / min. The results are shown in Table 3 below.

[0215] Table 3

[0216]

[0217] (2) HOMO energy levels of the compound

[0218] The LUMO level of the material in a vacuum environment was measured using an AC-2 photoelectron spectrometer. The compound of this application was deposited on an ITO substrate to form a thin film. The AC-2 testing conditions were 50 nW - step 0.05 nW. The band gap (Eg) of the material was measured using a UV spectrophotometer, and the HOMO level was calculated from the LUMO level and Eg. The results are shown in Table 4 below.

[0219] Table 4

[0220]

[0221] As can be seen from Table 3, the glass transition temperatures of the compounds in this application are all higher than 140℃, and they have good thermal stability, which is beneficial to improving the lifetime and luminous stability of organic electroluminescent devices.

[0222] As shown in Table 4, the compounds in this application generally have deeper HOMO (highest occupied molecular orbital) structures, which is beneficial for blocking holes migrating from the anode direction, reducing device leakage current, and thus improving device current efficiency. Comparing the hole-blocking materials of this application with currently available hole-blocking materials on the market, it can be seen that devices fabricated using the hole-blocking materials of this application exhibit better performance. The hole-blocking materials in this application possess higher HOMO and triplet energy levels, as shown in Table 4. Higher HOMO energy levels can reduce the number of holes leaving the emissive layer, thereby increasing the recombination probability of electrons and holes in the emissive layer. Higher triplet energy levels can reduce the number of excitons leaving the emissive layer, thereby improving the efficiency of exciton conversion luminescence. Therefore, the current efficiency and lifetime of the device are significantly improved. However, the performance of the electron transport material using structure II in the comparative example is reduced.

[0223] As shown in Table 2, the devices fabricated using the compounds of this application as hole-blocking materials all have operating voltages below 3.82V, current efficiencies above 8.2cd / A, and room-temperature lifetimes above 320 hours and high-temperature lifetimes above 205 hours. Comparative Examples 1 to 6, which use compounds other than those of this application as hole-blocking layer materials, show increased voltage, decreased efficiency, and shortened lifetimes. Comparative Examples 4 and 5, which do not use compounds of Structural Formula I or Structural Formula II as hole-blocking layer materials or electron transport materials, exhibit significantly reduced device performance.

[0224] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0225] The embodiments described above are merely illustrative of several implementation methods of this application, intended to facilitate a detailed understanding of the technical solutions of this application, but should not be construed as limiting the scope of protection of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. It should be understood that technical solutions obtained by those skilled in the art based on the technical solutions provided in this application through logical analysis, reasoning, or limited experimentation are all within the scope of protection of the appended claims. Therefore, the scope of protection of this patent application should be determined by the content of the appended claims, and the specification can be used to interpret the content of the claims.

Claims

1. A cyclohexylfluorene compound, characterized in that, It has the structure shown in the following general formulas (I-1) to (I-2): （I-1）、 （I-2）， Where L is ; Z is N; R1 and R2 are each independently a substituted or unsubstituted C6-C10 aryl group, wherein the substituted C6-C10 aryl group is selected from... , , , , , , or At least one of R1 and R2 is a substituted C6~C10 aryl group.

2. The cyclohexylfluorene compound according to claim 1, characterized in that, The cyclohexylfluorene compound is any one of the following compounds: 、 、 、 、 、 。 3. The use of the cyclohexylfluorene compound according to any one of claims 1 to 2 as a hole blocking layer material and / or an electron transport layer material.

4. The application of the cyclohexylfluorene compounds according to any one of claims 1 to 2 in organic electroluminescent devices, organic solar cells, organic thin-film transistors, organic photodetectors, organic field-effect transistors, organic integrated circuits, or organic photosensors.

5. An organic electroluminescent device, characterized in that, It includes a first electrode, a second electrode, and a light-emitting unit disposed between the first electrode and the second electrode, wherein the light-emitting unit contains at least one of the cyclohexylfluorene compounds according to any one of claims 1 to 2.

6. The organic electroluminescent device according to claim 5, characterized in that, The light-emitting unit includes a hole-blocking layer and an electron transport layer, wherein the hole-blocking layer and / or the electron transport layer comprises at least one of the cyclohexylfluorene compounds according to any one of claims 1 to 2.

7. The organic electroluminescent device according to claim 6, characterized in that, The hole-blocking layer comprises at least one of the cyclohexylfluorene compounds; the electron transport layer comprises a compound having the structure shown in general formula (II): (II) Among them, R 1 -R 7 Independently represented as hydrogen, deuterium, cyano, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C3-C60 heteroaryl, wherein the substituted substituent is selected from one or more of deuterium, C1-C5 alkyl, C6-C60 aryl or C3-C60 heteroaryl; L 1 and L 2 It is represented as a single bond, a substituted or unsubstituted C6-C60 arylene, a substituted or unsubstituted C3-C60 heteroarylene, wherein the substituted substituent is selected from one or more of deuterium, C1-C5 alkyl, C6-C60 aryl or C3-C60 heteroaryl; Ar 1 and Ar 2 Independently represented as a substituted or unsubstituted C6-C60 aryl, a substituted or unsubstituted C3-C60 heteroaryl, wherein the substituent is selected from one or more of deuterium, C1-C5 alkyl, C6-C60 aryl or C3-C60 heteroaryl.

8. The organic electroluminescent device according to claim 7, characterized in that, R 1 -R 7 Independently represented as hydrogen, deuterium, methyl, deuterated methyl, ethyl, phenyl, deuterated benzene, naphthyl, biphenyl, or tolyl.

9. The organic electroluminescent device according to claim 7, characterized in that, L 1 and L 2 It is represented as a single bond, phenylene, or deuterated phenylene.

10. The organic electroluminescent device according to claim 7, characterized in that, Ar 1 and Ar 2 Independently represented as phenyl, deuterated phenyl, tolyl, biphenyl, naphthyl, phenanthryl, anthracene, perylene, fluoranthracene, pyrene, phenylnaphthyl, naphthylphenyl, diphenylphenyl, 9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, benzyl, 9,9-spirodifluorenyl, benzofuranyl, benzothiophene, dibenzofuranyl, dibenzothiophene, benzo[fluorene-9,9'-oxazanthene], pyridyl, benzylphenyl, pyridylphenyl, indolyl, carbazolylindolyl, fluorenylcarbazolyl, imidazolyl, oxazolyl, thiazolyl, thiadiazolyl, quinolinyl, isoquinolinyl, quinazolinyl, quinoxolinyl, azadibenzofuranyl or azadibenzothiophene.

11. The organic electroluminescent device according to any one of claims 7 to 10, characterized in that, R 1 -R 7 The total number of deuteriums mentioned is 0 to 10.

12. A display device, characterized in that, The organic electroluminescent device included in any one of claims 5 to 11.

Images