JP2017031112A - Phosphorescence material for organic electroluminescent device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compound having triplet energy, which provides efficiency and stability to an organic electroluminescent device, of 2.5 eV or more by using for a phosphorescent host material in a luminescent layer or an electron transport material or an exciton block.SOLUTION: There is provided an organic material having a compound represented by the formula (I) and high in triplet energy. There is provided an organic material which is an organic amorphous thin film with 1 to 500 nm by vacuum deposition or a wet method. Formula (I), where X is O or S, Z is a substituted/unsubstituted heteroaromatic ring having at least two nitrogen atoms or a C2-6 alkyl group.SELECTED DRAWING: None

Description

  The present invention relates to a non-radioactive material of formula (I) for producing an organic electroluminescent device and a composition comprising said non-radioactive material.

  Organic light-emitting devices (Organic Light-Emitting Devices, OLED) have attracted attention in recent years because they have properties such as high brightness, fast refresh rate and wide color gamut, and are more suitable for application to portable electronic devices. Yes.

  In general, an OLED includes an anode, a hole transport layer, a light emitting layer, an electron transport layer, and a cathode, which are sequentially deposited by vacuum deposition or coating techniques. When a voltage is provided, holes from the anode are injected into the organic layer and electrons from the cathode are injected into the organic layer. The injected holes move to the light emitting layer via the hole transport layer, and the electrons move to the light emitting layer via the electron transport layer. In the light emitting layer, excitons are generated by recombination of holes and electrons. Light is emitted when the excitons are relaxed by the photoelectron emission mechanism.

  Reasons for manufacturing organic light emitting (EL) display devices that include multiple layers of thin film structures include stabilizing the interface between the electrode and the organic layer. In addition, since the mobility of electrons and holes is significantly different for organic materials, holes and electrons can be efficiently converted into a luminescent layer by using an appropriate hole transport layer and electron transport layer. ). Further, if the density of holes and electrons in the light emitting layer is balanced, the luminous efficiency can be improved. Appropriate combinations of the organic layers described above can improve device efficiency and lifetime. However, it is extremely difficult to find an organic material that satisfies all the requirements for application applications of actual display devices.

  The luminescent materials used in the first OLED emit light in their singlet state and are referred to as “fluorescence”. Fluorescence emission generally occurs within a time range of 10 nanoseconds or less. Patent Document 1 (US Pat. No. 4,769,292), Patent Document 2 (US Pat. No. 5,844,363), and Patent Document 3 (US Pat. No. 5,707,745) describe several arrangements of OLED materials and devices using fluorescence. All of which are incorporated herein by reference.

  More recently, OLEDs having a light-emitting material that emits light from a triplet state (“phosphorescence”) are disclosed in Non-Patent Document 1 (Nature, 1998, No. 395, p. 151) and Non-Patent Document 2 (Appl. Phys. Lett. , 1999, No. 3, p.4), and U.S. Pat. No. 7,279,704, the entire contents of which are incorporated herein by reference.

  For high emission and efficient phosphorescent OLEDs, the host material must have charge (hole / electron) injection / transport properties balanced with non-radiative high triplet energy. The host material should also have good electrochemical stability, high heat resistance and excellent thin film stability. However, until now, no compound has yet been known that can satisfy all the above properties in terms of practicality.

  Patent Documents, for example, Patent Document 5 (WO2003 / 78451), Patent Document 6 (WO2005 / 76668), Patent Document 7 (US Patent Publication No. 2006-51616), Patent Document 8 (Japanese Patent Application Laid-Open No. 2008-516). No. 280330), Patent Document 9 (WO 2008/123189), and Patent Document 10 (Japanese Patent Laid-Open No. 2009-21336) attempt to disclose materials having excellent ambipolar transport properties. However, since the energy levels of molecular orbitals with adjacent layers in organic electroluminescent devices are mismatched, there remains a challenge to achieve high efficiency and good device stability.

U.S. Pat. No. 4,769,292 US Pat. No. 5,844,363 US Pat. No. 5,707,745 U.S. Pat. No. 7,279,704 WO2003 / 78451 WO2005 / 76668 US Patent Publication No. 2006-51616 JP 2008-280330 A WO2008 / 123189 JP 2009-21336 A

Nature, 1998, no. 395, p. 151 Appl. Phys. Lett. , 1999, no. 3, p. 4

  In order to solve the above problems, the present invention improves the luminous efficiency and stability of a device by being used as a phosphorescent host material or electron transport material in a light emitting layer, or an exciton blocking layer in an organic light emitting device. It is an object of the present invention to provide an organic compound. In particular, the present invention discloses various compounds that have triplet energy of 2.5 eV or more and have excellent electron transport properties to bring efficiency and stability to organic EL devices.

The present invention provides an organic material having a compound of the following formula (I).

  In the formula, X represents an oxygen or sulfur atom. Z represents a substituted or unsubstituted heteroaromatic ring containing at least two nitrogen atoms or a C2-C6 alkyl group.

  In one embodiment of the invention, the triplet energy of the material represented by formula (I) is 2.5 eV or more.

  In another embodiment of the present invention, a process for preparing a specific compound represented by formula (I) is provided.

  In another embodiment of the present invention, there is provided an organic electroluminescent device in which the above compound is used in an organic layer, and the organic layer has a thickness of 1 nm to 500 nm.

  The compound represented by the formula (I) in the present invention may be produced as an amorphous thin film by vacuum deposition or a wet method for an organic electroluminescent device.

  The present invention can provide an organic electroluminescent device having high efficiency and good device stability.

1 is a cross-sectional view illustrating one example of an organic light emitting device according to an example of the present invention. It is sectional drawing which shows the other example of the organic light emitting device by the other example of this invention. It is sectional drawing which shows the further another example of the organic light emitting device by the other example of this invention. FIG. 4 is a diagram showing an electroluminescent spectrum of an organic electroluminescent device according to the present invention. FIG. 4 is a diagram of electroluminescent device luminous rate versus current density according to the present invention.

  Hereinafter, the present invention will be described using specific examples. Those skilled in the art can readily understand these and other advantages and effects by reading the present specification.

The compound used for the organic electroluminescent device according to the present invention is represented by the following formula (I).

  In the formula (I), X represents an oxygen or sulfur atom. Z represents a substituted or unsubstituted heteroaromatic ring containing at least two nitrogen atoms or a C2-C6 alkyl group. Preferred examples of the compound represented by the formula (I) are shown in Table 1 below. However, the present invention is not limited to them.

  Exemplified compounds F1-F20 represented by formula (I) may be produced by a series of reactions shown in Synthesis Scheme 1-4, but the present invention is not limited thereto.

  The organic electroluminescent device of the present invention has at least one light-emitting layer between an anode and a cathode superimposed on a substrate, and a phosphorescent dopant and the above compound represented by formula (I) as a host material A light emitting layer is included. Preferably, the hole injection / transport layer is disposed between the anode and the light emitting layer, and the electron injection / transport layer is disposed between the cathode and the light emitting layer. Preferably, the hole blocking layer is disposed between the light emitting layer and the electron injection / transport layer, and the electron blocking layer is disposed between the hole injection / transport layer and the light emitting layer.

  Furthermore, the compound represented by the formula (I) may be used in an electron injection / transport layer or a hole blocking layer and / or an electron blocking layer.

  The phosphorescent dopant used in the light emitting layer is preferably an organometallic complex containing at least one metal selected from ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, and gold. Such organometallic complexes are known in the above-mentioned patent documents, and an appropriate complex can be selected from these complexes and used in the present invention.

Preferred phosphorescent dopants include complexes having a noble metal element (eg Ir) at the center (typically Ir (ppy) ₃ ), Ir (bt) ₂ (acac), complexes such as FIrpic, complexes such as PtOEt ₃ However, the present invention is not limited thereto.

  The phosphorescent dopant content in the light emitting layer is preferably in the range of 3 wt% to 10 wt%.

  The structure of the organic light emitting device according to the present invention will be described with reference to the drawings, but the present invention is not limited thereto.

  FIG. 1 is a schematic view of an organic light emitting device 100 according to an embodiment of the present invention. The device 100 may include a substrate 110, an anode 120, a hole injection layer 130, a hole transport layer 140, a light emitting layer 150, an electron transport layer 160, an electron injection layer 170, and a cathode 180. The device 100 may be manufactured by laminating the above layers in order.

  FIG. 2 is a schematic diagram of an organic light emitting device 200 according to an embodiment of the present invention. The device 200 may include a substrate 210, an anode 220, a hole injection layer 230, a hole transport layer 240, an exciton blocking layer 245, a light emitting layer 250, an electron transport layer 260, an electron injection layer 270, and a cathode 280.

  FIG. 3 is a schematic view of an organic light emitting device 300 according to an embodiment of the present invention. The device 300 may include a substrate 310, an anode 320, a hole injection layer 330, a hole transport layer 340, a light emitting layer 350, an exciton blocking layer 355, an electron transport layer 360, an electron injection layer 370, and a cathode 380.

  It is also possible to manufacture an organic light emitting device having a structure opposite to that shown in FIGS. In this reverse structure, one or more layers may be added or deleted as necessary.

  The material used for the hole injection layer, hole transport layer, electron block layer, hole block layer, electron transport layer, or electron injection layer may be selected from materials reported in any literature.

  The organic light emitting device according to the present invention can be applied to a single device, a device having a structure arranged in an array, or a device having an anode and a cathode arranged in an XY matrix.

  Compared to a device having a conventional phosphorescent OLED device structure, the organic light emitting device of the present invention significantly improves the lifetime stability.

  For example, an electron transport material for forming an electron transport layer, unlike a material for forming a light emitting layer, has a hole transport property, thereby promoting hole mobility in the electron transport layer, and Carrier accumulation due to a difference in ionization potential between them can be prevented.

  In addition, US Pat. No. 5,844,363 (incorporated herein in its entirety) discloses a flexible and transparent substrate and anode combination. US Patent Publication No. 20030230980 (incorporated herein in its entirety) discloses an example of a p-doped hole transport layer in which the molar ratio is 50: 1 and F4-TCNQ is doped in m-MTDATA. . US Patent Publication No. 20030230980 (incorporated herein in its entirety) discloses an example of an n-doped electron transport layer in which the molar ratio is 1: 1 and Li is doped into BPhen. U.S. Pat. Nos. 5,703,436 and 5,707,745 (incorporated herein in their entirety) are metals that are transparent, conductive and covered with a sputter-deposited ITO layer (eg, An example of a cathode comprising a compound cathode having a Mg: Ag) thin film is disclosed. The theory and use of blocking layers is described in US Pat. No. 6,097,147 and US Pat. Publication No. 20030230980, the entire contents of which are incorporated herein by reference. US Patent Publication No. 2004014174 (incorporated herein in its entirety) discloses an example of an injection layer. Also, U.S. Patent Publication No. 2004014174 (all content is cited in the present invention) describes a protective layer.

  Structures and materials not specifically described may be used, for example, OLEDs (PLEDs) containing polymeric materials disclosed in US Pat. No. 5,247,190, the entire contents of which are incorporated herein by reference. May be used. OLEDs that include a single organic layer may also be used. OLEDs may be stacked as described in US Pat. No. 5,707,745, the entire contents of which are incorporated herein.

  Unless otherwise specified, each layer of the various embodiments may be deposited by any suitable method. For organic layers, a preferred method is thermal evaporation, ink-jet described in US Pat. No. 6,139,982 and US Pat. No. 6,087,196, the entire contents of which are incorporated herein by reference, US Pat. No. 6,337,102. (Organic vapor phase deposition, OVPD) and US patent application Ser. No. 10 / 233,470 (all contents cited in the present invention). Including deposition by the described organic vapor jet printing (OVJP). Other suitable deposition methods include spin coating and other solution based processes. The solution based process is preferably performed in nitrogen or an inert atmosphere. For the other layers, suitable methods include thermal evaporation. Suitable patterning methods include mask deposition, cold welding and ink jet as described in US Pat. No. 6,294,398 and US Pat. No. 6,468,819, the entire contents of which are incorporated herein by reference. And patterning associated with the deposition method, such as OVJD. Of course, other methods may also be used. The deposited material may be modified to suit a particular deposition method.

  The present invention significantly improves the light emitting efficiency and driving stability of organic light emitting devices compared to conventional devices when a combination of phosphorescent dopants is used in the light emitting layer. Furthermore, the organic light emitting device according to the present invention has a better performance when applied to a full color or multicolor panel.

EXAMPLES In order to clarify the nature and effectiveness of the present invention, the present invention will be described in detail using the following examples. However, the present invention is not limited to these specific examples without departing from the spirit of the present invention.

  The materials used in the synthetic examples disclosed in this patent were prepared in the following manner.

Synthesis Example 1 (Synthesis of Compound F1)
In a 2 L flask, 4- (3-chlorophenyl) dibenzo [b, d] furan (38.0 g), 11,12-dihydroindolo [2,3-a] carbazole (35 g), bis (dibenzylideneacetone) A mixture of palladium (0) (2.3 g), sodium-tert-butoxide (39.3 g), xylene (875 ml) and tri-tert-butylphosphine (2.21 g) was charged and refluxed in a nitrogen atmosphere. The reaction was monitored by thin layer chromatography. After the reaction was complete, the reaction mixture was quenched with water (500 ml) and extracted using ethyl acetate (500 ml). The organic layer was extracted using water (5 × 250 ml) and dried over anhydrous sodium sulfate. For further purification, the collected ethyl acetate layers were passed through celite column chromatography. Subsequently, the ethyl acetate layer was evaporated and dried using a rotary evaporator under reduced pressure. The residue was further precipitated by charging 500 ml of n-hexane, filtering and drying under reduced pressure, and 11- (3- (dibenzo [b, d] furan-4-yl) phenyl) -11,12-dihydro 51 g of indolo [2,3-a] -carbazole was obtained.
A 1 L flask was charged with 11- (3- (dibenzo [b, d] furan-4-yl) phenyl) -11,12-dihydroindolo [2,3-a] -carbazole (50 g), sodium hydride ( 69.4 g) and tetrahydrofuran (500 ml) were charged, and the mixture was stirred at 40 ° C. in a nitrogen atmosphere. After 1 hour, 2-chloro-4,6-diphenyl-1,3,5-triazine (32 g) was added and stirring was continued overnight. The reaction was monitored by thin layer chromatography. After the reaction was complete, the reaction mixture was quenched with water (200 ml) and extracted using ethyl acetate (300 ml). The organic layer was extracted using water (3 × 150 ml) and dried over anhydrous sodium sulfate. For further purification, the collected ethyl acetate layers were passed through celite column chromatography. Subsequently, the ethyl acetate layer was evaporated and dried using a rotary evaporator under reduced pressure. The residue was further precipitated by charging 300 ml of methanol, filtering and drying under reduced pressure. As a pale yellow solid, 36.1 g (49% yield) of Compound F1 having an HPLC purity of 99% was obtained.
Compound F1 had a melting point of 251 ° C. and a glass transition temperature of 144 ° C.
1H NMR (CDCl ₃ , 400 MHz) δ: 8.76-8.70 (s, 1H); 8.32-8.20 (m, 2H); 8.22-8.06 (m, 4H); 65-7.59 (m, 1H); 7.58-7.10 (m, 23H).
The observed triplet energy of Compound F1 was 2.52 eV.

Synthesis Example 2 (Synthesis of Compound F2)

  In a 500 ml flask, 4- (3-chlorophenyl) dibenzo [b, d] thiophene (17.2 g), 11,12-dihydroindolo [2,3-a] carbazole (15 g), bis (dibenzylideneacetone) A mixture of palladium (0) (1 g), sodium-tert-butylbutoxide (16.68 g) and tri-tert-butylphosphine (1.01 g) was charged and refluxed with xylene (375 ml) in a nitrogen atmosphere. The reaction was monitored by thin layer chromatography. After the reaction was complete, the reaction mixture was quenched with water (200 ml) and extracted using ethyl acetate (300 ml). The organic layer was extracted using water (5 × 50 ml) and dried over anhydrous sodium sulfate. For further purification, the collected ethyl acetate layers were passed through celite column chromatography. Subsequently, the ethyl acetate layer was evaporated and dried using a rotary evaporator under reduced pressure. The residue was further precipitated by charging 200 n-hexane, filtering and drying under reduced pressure, and 11- (3- (dibenzo [b, d] thiophen-4-yl) phenyl) -11,12-dihydro. Indolo [2,3-a] -carbazole (15.5 g) was obtained.

A 1 L flask was charged with 11- (3- (dibenzo [b, d] thiophen-4-yl) phenyl) -11,12-dihydroindolo [2,3-a] carbazole (15 g), sodium hydride (20 .16 g) and tetrahydrofuran (400 ml) were charged together and stirred at 40 ° C. in a nitrogen atmosphere. After 1 hour, 2-chloro-4,6-diphenyl-1,3,5-triazine (9.36 g) was added and stirring was continued overnight. The reaction was monitored by thin layer chromatography. After the reaction was complete, the reaction mixture was quenched with water (120 ml) and extracted using ethyl acetate (200 ml). The organic layer was extracted using water (3 × 150 ml) and dried over anhydrous sodium sulfate. For further purification, the collected ethyl acetate layers were passed through celite column chromatography. Subsequently, the ethyl acetate layer was evaporated and dried using a rotary evaporator under reduced pressure. 200 ml of methanol was added, filtered and dried under reduced pressure to further precipitate the residue. As a yellow solid, 16.5 g (76%) of Compound F2 having an HPLC purity of 99% was obtained.
Compound F2 had a melting point of 295.2 ° C and a glass transition temperature of 154 ° C.
1H NMR (CDCl ₃ , 400 MHz) δ: 8.74-8.71 (d, 1H); 8.63-8.45 (s, 1H); 8.39-8.28 (t, 3H); 23-8.08 (m, 4H); 7.69-6.95 (m, 22H).
The triplet energy of the observed compound F2 was 2.57 eV.

Synthesis Example 3 (Synthesis of Compound F3)
Similarly to the production method of Synthesis Example F1, 36 g (66% yield) of Compound F3 having an HPLC purity of 99% was prepared.
Compound F3 had a melting point of 251 ° C. and a glass transition temperature of 144 ° C.
1H NMR (CDCl ₃ , 400 MHz) δ: 8.59-8.62 (dd, 1H); 8.36-8.40 (m, 4H); 8.29-8.34 (m, 2H); 16-8.19 (dd, 1H); 8.11-8.14 (d, 1H); 7.91-7.94 (d, 1H); 7.73-7.75 (m, 1H); 7.56-7.65 (d, 4H); 7.39-7.52 (m, 7H); 7.34-7.37 (m, 1H); 7.26-7.3 (m, 3H) ); 7.20-7.24 (m, 3H); 6.99-7.06 (m, 2H).
The observed triplet energy of Compound F3 was 2.67 eV.

Synthesis Example 4 (Synthesis of Compound F4)
In the same manner as in Synthesis Example F2, 89 g (72% yield) of Compound F4 having an HPLC purity of 99% was prepared.
Compound F4 had a melting point of 286 ° C. and a glass transition temperature of 162 ° C.
1H NMR (CDCl ₃ , 400 MHz) δ: 8.68-8.69 (d, 1H); 8.49-8.54 (d, 4H); 8.3-8.36 (m, 2H); 17-8.21 (d, 1H); 8.12-8.14 (d, 1H); 8.07-8.11 (d, 1H); 7.95-7.97 (m, 1H); 7.68-7.72 (m, 1H), 7.62-7.65 (m, 1H); 7.52-7.57 (t, 3H); 7.39-7.5 (m, 11H) 7.20-7.24 (dd, 2H); 7.07-7.11 (t, 1H); 6.81-6.83 (dd, 1H).
The triplet energy of the observed compound F4 was 2.58 eV.

Synthesis Example 5 (Synthesis of Compound F5)
To a 1 L flask was added 11- (3- (dibenzo [b, d] furan-4-yl) phenyl) -11,12-dihydroindolo [2,3-a] -carbazole (20 g), sodium hydride ( 4.8 g) and toluene (300 ml) were charged, and the mixture was stirred at 40 ° C. in a nitrogen atmosphere. After 1 hour, 2-chloro-4,6-diphenyl-1,3-pyrimidine (12.8 g) was added and stirring was continued at 80 ° F. The reaction was monitored by thin layer chromatography. After the reaction was complete, the reaction mixture was quenched with water (200 ml) and extracted using ethyl acetate (150 ml). The organic layer was extracted using water (3 × 100 ml) and dried over anhydrous sodium sulfate. For further purification, the collected ethyl acetate layers were passed through celite column chromatography. Subsequently, the ethyl acetate layer was evaporated and dried using a rotary evaporator under reduced pressure. The residue was further precipitated by adding 100 ml of n-hexane, filtering and drying under reduced pressure. As a yellow solid, 18 g (85%) of Compound F5 having an HPLC purity of 99% or more was obtained.
Compound F5 had a melting point of 267 ° C. and a glass transition temperature of 151 ° C.
1H NMR (CDCl ₃ , 400 MHz) δ: 8.37-8.40 (m, 1H); 8.28-8.31 (d, 1H); 8.27-8.28 (t, 1H); 18-8.21 (m, 1H); 8.16-8.18 (d, 1H); 7.96-7.99 (dd, 1H); 7.92-7.96 (dd, 1H); 7.68-7.67 (t, 1H); 7.64-7.68 (m, 1H); 7.45-7.49 (m, 1H); 7.34-7.42 (t, 6H) ); 7.15-7.34 (m, 14H); 7.06-7.10 (m, 2H).
The observed triplet energy of Compound F5 was 2.51 eV.

Synthesis Example 6 (Synthesis of Compound F6)
Similarly to the production method of Synthesis Example F5, 18 g (62% yield) of Compound F6 having an HPLC purity of 99% was prepared.
Compound F6 has a melting point of 267 ° C. and a glass transition temperature of 151 ° C.
1H NMR (CDCl ₃ , 400 MHz), δ: 8.37-8.4 (m, 1H); 8.27-8.31 (m, 2H); 8.19-8.21 (m, 1H); 8 .16-8.17 (d, 1H); 7.93-7.96 (d, 1H); 7.87-7.91 (m, 3H); 7.75-7.78 (m, 1H) 7.65-7.70 (m, 2H); 7.55-7.59 (m, 2H); 7.47-7.52 (m, 2H), 7.35-7.44 (m, 4H); 7.08-7.30 (m, 12H).
The observed triplet energy of Compound F6 was 2.50 eV.

Synthesis Example 7 (Synthesis of Compound F13)
To a 1 L flask was added 11- (3- (dibenzo [b, d] furan-4-yl) phenyl) -11,12-dihydroindolo [2,3-a] -carbazole (20 g), sodium hydride ( 4.8 g) and toluene (300 ml) were charged together and stirred at 40 ° C. in a nitrogen atmosphere. After 1 hour, 2-bromoethane (8.8 g) was added and stirring was continued at 80 ° F. The reaction was monitored by thin layer chromatography. After the reaction was complete, the reaction mixture was quenched with water (200 ml) and extracted using ethyl acetate (150 ml). The organic layer was extracted using water (3 × 100 ml) and dried over anhydrous sodium sulfate. For further purification, the collected ethyl acetate layers were passed through celite column chromatography. Subsequently, the ethyl acetate layer was evaporated and dried using a rotary evaporator under reduced pressure. The residue was further precipitated by adding 100 ml of n-hexane, filtering and drying under reduced pressure. As a yellow solid, 18 g (85%) of Compound F13 having an HPLC purity of 99% or more was obtained.
Compound F13 had a glass transition temperature of 108 ° C.
1H NMR (CDCl ₃ , 400 MHz) δ: 8.21-8.23 (m, 1H); 8.19-8.21 (t, 2H); 8.11-8.13 (d, 1H); 05-8.07 (d, 1H); 7.98-8.00 (t, 1H); 7.93-7.97 (m, 2H); 7.56-7.65 (d, 4H); 7.68-7.74 (m, 2H); 7.62-7.65 (m, 1H); 7.51-7.54 (m, 1H) 7.29-7.46 (m, 4H); 7.12-7.15 (m, 1H); 3.75-3.85 (q, 2H); 0.90-0.96 (q , 3H).
The observed triplet energy of Compound F13 was 2.51 eV.

Synthesis Example 8 (Synthesis of Compound F15)
In the same manner as in Synthesis Example F13, 36 g (66% yield) of Compound F15 having an HPLC purity of 99% was prepared.
Compound F15 had a glass transition temperature of 109 ° C.
1H NMR (CDCl ₃ , 400 MHz) δ: 8.19-8.21 (d, 1H); 8.15-8.19 (m, 3H); 8.11-8.12 (s, 1H); 09-8.11 (s, 1H), 8.03-8.04 (d, 1H); 7.99-8.02 (m, 1H); 7.72-7.75 (m, 1H); 7.64-7.68 (m, 3H); 7.69-7.61 (d, 1H); 7.47-7.53 (m, 1H); 7.34-7.45 (m, 5H) 7.28-7.3 (d, 1H); 7.12-7.15 (m, 1H); 3.74-3.80 (q, 2H); 0.85-0.95 (q) 3H).
The observed triplet energy of Compound F15 was 2.52 eV.

Example 1 (Manufacture of an organic electroluminescent device)
Before putting the substrate into the evaporation system, the substrate was degreased with a solvent in advance and cleaned with ultraviolet ozone. Subsequently, the substrate was moved to a vacuum evaporation chamber and all other layers were deposited on the substrate. The following layers were deposited in sequence as shown in FIG. 2 by evaporation in a hot boat under a vacuum of about 10 ⁻⁶ Torr.
a) Hole injection layer: HATCN
b) Hole transport layer: HT1
c) Exciton-blocking layer: BL (owned material of eRay optoelectronics Tech Co. Ltd., Taiwan)
d) Light-emitting layer: including red-light-emitting phosphorescent dopant RD1 and main host material selected from patent example (F1-F20), joint host CH1 (owned by eRay optoelectronics Tech Co. Ltd, Taiwan) Electron transport layer: ET
f) Electron injection layer: LiF
g) Cathode: The thickness is about 150 nm and contains Al.
The structure of the organic electroluminescent device may be represented as follows: ITO / HATCN (15 nm) / HT (140 nm) / BL (15 nm) / 3% RD1: Compound F4: CH1 (30 nm) / ET ( 30 nm) / LiF (1 nm) / Al (150 nm).

Comparative Example 1:
A red light emitting phosphorescent device is manufactured in the same manner as in Example 1 except that CBP having RD1 in the light emitting layer is used as a light emitting host. The device structure may be represented as follows: ITO / HATCN (15 nm) / HT (140 nm) / BL (15 nm) / 3% RD1: CBP (30 nm) / ET (30 nm) / LiF (1 nm) / Al (150 nm).
After depositing these layers, the device was moved from the deposition chamber to a dry box for sealing, followed by sealing using a UV curable epoxy resin and a glass lid containing a moisture getter. . The organic EL device has a light emitting area of 3 mm ² . The obtained organic EL device was connected to an external power source and used under a DC voltage, and the properties of light emission shown in Table 2 were confirmed. The electroluminescent spectrum of the device is shown in FIG.

All the EL properties of the devices manufactured in the present invention are as follows: constant current source (KEITHLEY 2400 Source Meter, Keithley Instruments Inc., Cleveland, Ohio) and photometer (PHOTO RESEARCH SpectraScan PR 650, Photo Ltd. , Calif.) At room temperature.
The service life (or stability) of the device was measured at room temperature by passing a constant current through the device at an initial luminance of 10,000 cd / m ² . The color of light is shown in the color system of the International Commission on Illumination (CIE).

  Table 2 shows the emission peak wavelength, maximum emission efficiency, driving voltage, and external quantum efficiency of the organic electroluminescent device manufactured in this example. FIG. 5 shows a diagram of current density versus luminescence.

本発明は、上記の実例、方法と実施例に限られない。

The invention is not limited to the examples, methods and embodiments described above.

As described above, the organic EL device using the organic EL device material of the present invention has high luminous efficiency, high thermal stability, low driving voltage, and long life.
Therefore, the organic EL device of the present invention may be applied to a flat panel display, a mobile phone display, a light source utilizing the characteristics of a flat light emitter, and a signboard, and has high technical value.

  Although the invention has been described above with reference to specific preferred embodiments, those skilled in the art will recognize that the scope of the invention is not limited to the disclosed arrangements. Accordingly, the claimed scope of the present invention should be construed most broadly to encompass all similar adjustments and similar configurations.

100, 200, 300 Organic light emitting device 110, 210, 310 Substrate 120, 220, 320 Anode 130, 230, 330 Hole injection layer 140, 240, 340 Hole transport layer 150, 250, 350 Light emitting layer 160, 260, 360 Electron transport layer 170, 270, 370 Electron injection layer 180, 280, 380 Cathode 245 Exciton 355 Exciton block layer

In the formula, X represents an oxygen or sulfur atom. Z represents a C2-C6 alkyl group , a diphenyltriazinyl group, a diphenylpyrimidinyl group, or a carbolinyl group .

In the formula (I), X represents an oxygen or sulfur atom. Z represents a C2-C6 alkyl group or a substituted or unsubstituted heteroaromatic ring group containing at least two nitrogen atoms as hetero atoms . Preferred examples of the compound represented by the formula (I) are shown in Table 1 below. However, the present invention is not limited to them.

Claims (5)

An organic material having a compound of the following formula (I).

(In the formula, X represents an oxygen or sulfur atom. Z represents a substituted or unsubstituted heteroaromatic ring containing at least two nitrogen atoms or a C2-C6 alkyl group.) The organic material according to claim 1, wherein the triplet energy is 2.5 eV or more. The organic material according to claim 1, which is produced as an amorphous thin film by vacuum deposition or a wet method. The organic material of Claim 1 used for an organic layer. The organic material according to claim 4, wherein the organic layer has a thickness of 1 nm to 500 nm.

Images