TWI404790B - Red phosphorescent materials and organic electroluminescent photodiodes - Google Patents

Abstract

The present invention relates to a red phosphor material selected from the group consisting of the following carbazole compounds: SPH-1, SPH-2, SPH-3, SCH-1, SCH-2, and SCH-3. This invention also relates to an organic light emitting diode including: a substrate, an anode layer disposed on the substrate surface, a cathode layer disposed on one side of the substrate and opposite to the anode layer, and an organic light emitting layer disposed between the anode layer and the cathode layer and containing said red phosphor material. By using novel carbazole compounds in this invention, the red phosphor material can reduce stereoregularity, improve thermal resistance and is applied in organic light emitting diode (OLED) to obtain an OLED capable of emitting red phosphorescent light.

Description

Red phosphorescent material and organic electroluminescent diode

The present invention relates to a red phosphorescent material, in particular to a red phosphorescent material that can be applied to organic electroluminescent diodes (OLEDs) to enable OLEDs to act as phosphorescent light.

The organic electroluminescent diode typically comprises at least one organic layer connecting the cathode to the anode. When current is supplied, the cathode injects electrons and the anode injects holes into the organic layer. When the electron holes combine to form excitons, the localized electron hole pairs form an excited state. The excitons emit light back to steady state by a light-emitting mechanism.

In some instances, excitons can be localized in an activated eximer or excoplex, possibly in an amount efficiently delivered from the luminescent body to the luminescent center.

The use of singlet fluorescent materials was originally applied to OLEDs, such as U.S. Patent No. 4,769,292, which typically has a time lag of less than 10 nanoseconds (ns).

The use of triplet phosphorescent materials has recently been applied to OLEDs, as described in more detail in phosphorescence by Baldo, M.A. (1999) Appl. Phys. Lett., vol. 75: 4-6 and U.S. Patent No. 7,279,704.

Organic electroluminescent diodes are gaining more and more attention because of the following factors, the organic materials used as OLEDs have a price advantage over inorganic materials, and because of the flexibility of organic materials, they can be used to make flexible On the substrate. Organic electroluminescent devices include, but are not limited to, organic electroluminescent diodes, organic transistors, organic solar cells, organic detectors, and the like. For OLEDs, organic materials have more advantages than traditional materials. The color of light or the like can be adjusted by changing the wavelength of the light emission by doping different organic materials with the light-emitting layer.

Providing a driving voltage allows OLEDs to be made into an organic thin film to emit light. The technology of OLEDs is increasingly valued because it can be applied to flat panel displays, illumination, and backlights. The materials and structures of several OLEDs are described in detail in U.S. Patent Nos. 5,844,363, 6,303,238 and 5,707,745.

The inventors have drawn attention to the technology of OLEDs, and therefore actively research and develop OLEDs and related materials, so that OLEDs and related industries are more mature, and can be widely applied to various organic photodiodes, so the invention This can be used for red phosphorescent materials in OLEDs.

It is an object of the present invention to provide a red phosphorescent material, particularly a red phosphorescent material that can be applied to an organic light emitting diode to enable OLEDs to act as phosphorescent light.

To achieve the above object, the present invention provides a red phosphorescent material selected from the group consisting of the following carbazole compounds:

The present invention relates to an organic electroluminescent diode, which comprises: a substrate; an anode layer deposited on the surface of the substrate; and a cathode layer disposed on the anode layer different from the substrate One side; and an organic light-emitting layer disposed between the anode layer and the cathode layer, including the red phosphorescent material described above.

The organic electroluminescent diode further includes: a hole injection layer deposited on the surface of the anode layer; and an organic hole transport layer deposited on the surface of the hole injection layer, and An organic light-emitting layer is deposited on the surface thereof; an electron transport layer deposited on the surface of the organic light-emitting layer; an electron injection layer deposited on the surface of the electron transport layer; and a cathode layer deposited on the surface The surface of the electron injection layer.

Preferably, the substrate is made of transparent glass or plastic.

Preferably, the anode is transparent.

The present invention provides a novel synthetic carbazole compound which is capable of reducing stereoscopic rules and improving heat resistance. And it can be applied to an organic electroluminescent diode to exhibit an organic OLED capable of emitting red phosphorescence.

The present invention provides a red phosphorescent material selected from the group consisting of the following carbazole compounds:

The synthesis of each compound is as follows: First, the starting materials are synthesized, including the carbazole intermediate and the spiro intermediate:

Icarbazole intermediate

II. spiro intermediate

The two starting materials are then synthesized to produce the oxazole compound of the present invention:

a. SPH-1 (please refer to the nuclear magnetic resonance (NMR) spectrum, mass spectrometry analysis and fluorescence property analysis (UV/PL) spectrum shown in Figure 2-4)

b. SPH-2 (please refer to the nuclear magnetic resonance (NMR) spectrum, mass spectrometry analysis and fluorescence property analysis (UV/PL) spectrum shown in Figure 5-7)

c. SPH-3 (please refer to the nuclear magnetic resonance (NMR) spectrum, mass spectrometry analysis and fluorescence property analysis (UV/PL) spectrum shown in Figure 8-10)

d. SCH1-1 (please refer to the nuclear magnetic resonance (NMR) spectrum, mass spectrometry analysis and fluorescence property analysis (UV/PL) spectrum shown in Figure 11-13)

e. SCH1-2 (please refer to the nuclear magnetic resonance (NMR) spectrum, mass spectrometry analysis and fluorescence property analysis (UV/PL) spectrum shown in Figure 14-16)

f. SCH1-3 (please refer to the nuclear magnetic resonance (NMR) spectrum, mass spectrometry analysis and fluorescence property analysis (UV/PL) spectrum shown in Figure 17-19)

Further, SCH1, SCH2 and SCH3 can be manufactured as follows:

1. A synthetic route for the compound 9,9'-diethyl-9H, 9'H-3, 3'-biscarbazole 1 .

9-Ethylcarbazole (5 g, 25.6 mmol) and anhydrous ferric chloride (8.g. 51.2 mmol) were dissolved in dry chloroform and stirred vigorously at room temperature for 16 hours. The reaction was terminated by the addition of water, and the organic layer was extracted with dichloromethane, and then water was removed with magnesium sulfate. The organic layer was concentrated under reduced pressure, and then subjected to column chromatography to give Compound 1 (white powder).

2. Synthesis route of compound 6-bromo-9,9'-diethyl-9H, 9'H-3,3'-biscarbazole 2 .

Slowly add N- bromosuccinimide (NBS) (5.5 g, 30.0 mmol) to 9,9'-diethyl-9H, 9'H-3, 3'-biscarbazole 1 (12 g, 30.0 mmol) under nitrogen. The reaction was carried out for 2 hours at room temperature under a tetrahydrofuran solution. The reaction was terminated with water, the organic layer was extracted with dichloromethane, and then water was removed with magnesium sulfate. The organic layer was concentrated under reduced pressure and purified by column chromatography (hexane and dichloromethane) to afford compound 2 (white solid).

3. The synthetic route of the compound (9,9'-diethyl-9H,9'H-[3,3'-biscarbazol]-6-yl)boronic acid 3 .

6-bromo-9,9'-diethyl-9H,9'H-3,3'-biscarbazole 2 (4.0 g, 8.5 mmol) was placed in a double flask and dissolved in anhydrous tetrahydrofuran at -78 °C. Next, n-BuLi was slowly dropped into the reaction flask and stirring was continued for 1 hour; triethylborate (2.17 mL, 12.0 mmol) was added to the reaction flask under nitrogen. The reaction was terminated by the addition of water, and the organic layer was extracted with dichloromethane, and then water was removed with magnesium sulfate. The organic layer was concentrated under reduced pressure, and then dichloromethane (hexane) was used to obtain compound 3 (white solid).

4. The synthetic route of the compound 1-(2-bromophenyl)naphthalene 4 .

Naphthalene-l-boronic acid (10 g, 24.3 mmol), l-iodo-2-bromobenzene (6.64 g, 29.1 mmol) and tetrakis (triphenylphosphine) palladium (0) were placed in a double-necked flask and dissolved in tetrahydrofuran. Stir for 30 minutes at room temperature; slowly add sodium carbonate and heat to reflux for 24 hours. The reaction was quenched by the addition of water and the organic layer was extracted with dichloromethane. The organic layer was concentrated under reduced pressure, and then hexane was used as a solvent, which was separated by column chromatography and concentrated to give compound 4 (white solid).

5. Synthetic pathway of the compound 2-bromo-9,9'-spirobifluorene 5 .

2-bromophenyl (7.0 g, 30.0 mmol) was dissolved in anhydrous tetrahydrofuran at a temperature of -78 ° C under nitrogen, and n-BuLi (1.6 M in hexane, 22.4 mL) was slowly added; 2-bromo was first introduced. -9-fluorenone (9.3 g, 36.0 mmol) was dissolved in tetrahydrofuran (100 mL) and slowly added to the reaction. After returning to room temperature, the reaction was quenched with saturated aqueous sodium bicarbonate. The organic layer was extracted with dichloromethane, the water was removed by magnesium sulfate, and the layer was concentrated under reduced pressure to obtain a yellow powder. The yellow solid was dissolved in acetic acid (30 mL), and a catalytic amount of hydrochloric acid (5 mol%, 12 N) was added. Heated under reflux for 12 hours. After returning to room temperature, the organic layer was collected, concentrated under reduced pressure, and then extracted with dichloromethane and hexanes, and separated by column chromatography to give white solids. Bromospiro(benzo[c]fluorene-7,9'-fluorene)

The synthetic path of 6.

1-(2-bromophenyl)naphthalene (10 g, 35.3 mmol) was dissolved in anhydrous tetrahydrofuran (250 ml), and n-BuLi (2.5 M in hexane. 16.8) was slowly added at a temperature of -78 ° C under nitrogen. (M)), stirring was continued for 1 hour; 2-bromofluorenone (10.8 g, 41.7 mmol) was first dissolved in tetrahydrofuran (30 mL) and added to the reaction vessel. After returning to room temperature, with saturated carbon The aqueous sodium hydrogencarbonate solution was terminated, and the organic layer was extracted with dichloromethane. This yellow solid was dissolved in acetic acid (30 mL), and a catalytic amount of hydrochloric acid (5 mol%, 12 N) was added and heated to reflux for 12 hours. After returning to room temperature, the organic layer was collected, concentrated under reduced pressure, and then purified with dichloromethane and hexanes.

7. Synthetic pathway of the compound Spiro (benzo[c]fluorene-7,9'-fluorene)7.

1-(2-bromophenyl)naphthalene (9.42 g, 33.2 mmol) was dissolved in anhydrous tetrahydrofuran (250 ml), and n-BuLi (2.5 M in hexane) was slowly added at a temperature of -78 ° C under nitrogen. 14.4 mL), stirring was continued for 1 hour; 9-fluorenone (5.0 g, 27.7 mmol) was first dissolved in tetrahydrofuran (30 mL) and added to the reaction vessel. After returning to room temperature, the reaction was terminated with a saturated aqueous solution of sodium bicarbonate, and then the organic layer was extracted with dichloromethane. This yellow solid was dissolved in acetic acid (30 mL), and a catalytic amount of hydrochloric acid (5 mol%, 12 N) was added and heated to reflux for 12 hours. After returning to room temperature, the organic layer was collected, concentrated under reduced pressure, and then purified using dichloromethane and hexanes.

8. The synthetic route of the compound 5-bromospiro (benzo[c]fluorene-7,9'-fluorene)8.

Spiror [fluorene-7,9'-benzofluorene] 2 was dissolved in carbon tetrachloride, and bromine water was slowly added thereto over a period of 20 minutes, and the mixture was stirred at room temperature for 3 days, and the layer was concentrated under reduced pressure to give a product. Further, it was recrystallized from ethyl acetate and hexane to obtain a white powder.

9. Synthetic pathway of the compound 6-(9,9'-spirobifluoren-7-yl)-9,9'-diethyl-9H,9'H-3,3'-biscarba zole SCH1 .

2-bromo-9,9'-spirobifluorene (2.0 g, 5.0 mmol), (9,9'-diethyl-9H,9'H-[3,3'-biscarbazol]-6-yl) boronic under nitrogen Acid( 3 )(2.84 g, 6.5 mmol) and tetrakis-(triphenylphosphine)palladium(0) (0.29 g, 0.25 mmol) were dissolved in tetrahydrofuran (150 mL). After stirring for 1 hour, potassium carbonate was slowly added over 20 minutes. Reheated to 80 ° C and reacted for 12 hours. After returning to room temperature, and extracted with dichloromethane to water, an organic layer was collected, concentrated under reduced pressure by using hexane as an eluent, using column chromatography, to obtain yellow powder SCH1 and concentrated.

10. Synthesis of compound 9,9'-diethyl-6-{spiro(benzo[c]fluorene-7,9'-fluoren)-2'-yl}-9H,9'H-3,3'-biscarbazole SCH2 path.

2-bromo-spiro [fluorene-7,9'-benzofluorene (2.0 g, 4.49 mmol), (9,9'-diethyl-9H,9'H-[3,3'-biscarbazol]-6-yl) Boronic acid (3) (2.52 g, 5.83 mmol) and tetra-kis (triphenylphosphine) palladium (o) (0.26 g, 0.22 mmol) were dissolved in 30 mL of tetrahydrofuran, and stirred for 30 minutes under nitrogen; Potassium carbonate was slowly added over 20 minutes and heated to reflux for 24 hours. After returning to room temperature, it is extracted with dichloromethane and water, and the organic layer is collected, concentrated under reduced pressure, and then extracted with hexane, and then separated by column chromatography and concentrated to obtain white crystalline solid SCH2 .

11. Synthesis route of compound 9,9'-diethyl-6-{spiro[benzo[c]fluorene-7,9'-fluoren]-5-yl}-9H,9'H-3,3'-biscarbazole SCH3 .

5-Bromo-spiro [fluorene-7,9'-benzofluorene] (1.0 g.4.49 mmol), (9,9'-diethyl-9H,9'H-[3,3'-biscarbazol]-6-yl Boronic acid 3 (1.26 g, 5.83 mmol) and tetrakis-(triphenylphosphine) palladium (0) (0.13 g, 0.11 mmol) were dissolved in 35 mL of tetrahydrofuran, stirred for 1 hour with nitrogen; then, at 30 Within a minute, potassium carbonate was slowly added and heated at 90 ° C for 12 hours. After returning to room temperature, and extracted with dichloromethane to water, an organic layer was collected, concentrated under reduced pressure through, then hexane as an eluent, using column chromatography, to obtain white powder SCH3 and concentrated.

Please refer to Figure 20-27 for information on the electrical and physical properties of SPH1, SPH2, SPH3, SCH-1, SCH-2 and SCH-3.

Referring to Figure 1, a specific embodiment of an organic electroluminescent diode 10 of the present invention is shown. The organic OLED 10 comprises a transparent glass or plastic substrate 11 on which a transparent conductive anode layer 12 is deposited; an organic hole injecting material is deposited on the surface of the anode layer 12 to form a hole injection. a layer 13; a material of the organic hole transport layer 14 is deposited on the surface of the hole injection layer 13 to form an organic hole transport layer 14; an organic light-emitting layer 15 composed of a main light-emitting material containing a fluorescent dopant Deposited on the surface of the organic hole transport layer 14; depositing an electron transport layer 16 formed of an electron transport material on the surface of the organic light-emitting layer 15; and then depositing an electron injection layer 17 formed of an electron injecting material In the electron transport layer On the surface of 16; a metal conductive layer is deposited on the surface of the electron injecting layer 17 to form a cathode layer 18.

The organic light-emitting layer 15 is selected from the group consisting of the following carbazole compounds: SPH-1, SPH-2, SPH-3, SCH-1, SCH-2, and SCH-3.

In this particular embodiment, the electrically conductive anode layer 12 is a p-type contact and the electrically conductive cathode layer 18 is an n-type contact. A negative terminal of the power source 19 is connected to the cathode layer 18 and a positive terminal is connected to the anode layer 12. When a potential is applied between the anode layer 12 and the cathode layer 18 by the power source 19, electrons injected from the n-type contact point (cathode layer 18) will pass through the electron injecting layer 17 and the organic electron transporting layer 16, and The organic light-emitting layer 15 is entered, and holes injected from the p-type contact point (anode layer 12) are introduced into the organic light-emitting layer 15 through the organic hole injection layer 13 and the organic hole transport layer 14. When the electrons are recombined with the holes, the organic light-emitting layer 15 emits photons.

Example

A. Instruments and equipment:

1. Nuclear magnetic resonance (NMR) spectroscopy was measured by a VARIAN Unity 300 MHz nuclear magnetic resonance spectrometer, and CDCl ₃ was used as a standard compound.

2. Mass spectrometry was measured using MICROMASS TRIO-2000 GC/MS using the Rapid Atomic Impact (FAB) Free method.

3. The vacuum film evaporation machine (coater) is a TRC 18 吋 rotary evaporator, which can hold 6 substrates, 2 motorized baffles, 8 electric enthalpy, 5 oscillating sensors, IC-5 film. Thick controller and diffuser pump.

4. The spectrophotometer (colorimeter) was measured using a PhotoResearch PR-650 instrument.

5. The programmable power supply supplies current using a KEITHLEY 2400 instrument.

B. Production process:

1. Cleaning of the substrate: Prepare the ITO substrate that has been etched (the size of the ITO substrate is 40×40 mm), wash the ITO substrate with acetone, methanol and deionized water, place it in an oven, and bake at a temperature of 130 ° C. hour;

Second, the substrate before processing: the ITO substrate is taken out of the oven, placed in the plasma processor to activate according to the existing activation step;

3. Evaporation: The pre-processed ITO substrate is placed on a rotating carrier in the TRC vapor deposition machine. When the vacuum of the vapor deposition chamber reaches 10 ^-6 Torr, the evaporation of the vapor deposition material begins. The evaporation rate is monitored by a quartz sensor. In the embodiment of the present invention, the hole injection layer is vapor-deposited at a rate of 2 Å/s, NPB is evaporated at a rate of 2 Å/s, Alq ₃ is vapor-deposited at a rate of ₂ Å/s, and then at a rate of 0.1 Å/s. LiF was evaporated and Al was evaporated at a rate of 10 Å/s.

Fourth, component packaging: the package cover is glass material. After the glass cover is coated with UV glue, the newly fabricated component is placed in a nitrogen glove box together with the package cover, and the ITO substrate and the package cover are closely adhered by a heavy object, and the polymerization of the glue is performed by UV light. .

5. Measurement of component color and brightness: The packaged component is supplied with current by the power supply under the control of LabVIEW program, and the spectrum, brightness and luminosity (CIE _{x, y} ) of the component are measured by spectrophotometry. nature.

According to the method for measuring the color and the brightness, the examples of the present invention respectively measure the components of the compounds SPH1 to SPH-3 and SCH-1 to SCH-3 as the light-emitting layer, and the results are as follows:

Embodiment 1:

The indium tin oxide (ITO) glass substrate was 40 mm × 40 mm thick and 0.7 mm thick, ultrasonically cleaned in methanol for 12 minutes, and then irradiated with ultraviolet rays (to produce ozone) for 10 minutes. The cleaned glass substrate is moved into a vacuum vapor deposition apparatus. On the surface with a transparent electrode, a layer of DNTPD (N, N-diphenyl-N, N-bis-4-phenyl-m-tolyl-amino-phenyl-biphenyl'4,4-diamine) having a thickness of 60 nm is formed. The film is such that the formed film covers the transparent electrode. The film formed by DNTPD serves as a hole injection layer. Then, a 30 nm hole transport material (NPB) was formed on the DNTPD, and the formed film was an organic hole transport layer. The compound SPH-1 and Ir(piq) _{3 were} mixed by vacuum vapor deposition to form a compound SPH-1 having a thickness of 30 nm and an Ir(piq) ₃ containing 10% as an organic light-emitting layer. Further, a film having a thickness of 5 nm was formed as an electron transport layer by using 2,9-dimethyl-4,7-diphenyl-9,10-phenanthroline (BCP). A film having a thickness of 20 nm was formed as Al0 as a first electron injecting layer. Thereafter, lithium fluoride (LiF) was deposited on Alq as a second electron injection layer. Finally, the metal aluminum is vapor-deposited to form a metal cathode layer, and the organic electroluminescent diode is fabricated.

When the organic electroluminescence diode current density is 20 mA/cm ² , the driving voltage is 8.7 V. It emits red light with a luminance of 850 cd/m ² and a quantum efficiency of 4.6%.

Embodiment 2:

The indium tin oxide (ITO) glass substrate was 40 mm × 40 mm thick and 0.7 mm thick, ultrasonically cleaned in methanol for 12 minutes, and then irradiated with ultraviolet rays (to produce ozone) for 10 minutes. The cleaned glass substrate is moved into a vacuum vapor deposition apparatus. On the surface with a transparent electrode, a DNTPD film having a thickness of 60 nm is formed, so that the formed film covers the transparent electrode; the film formed by DNTPD is used as a hole injection layer; then a 30 nm NPB is formed on the DNTPD to form The film is a hole transport layer; the compound SPH-2 and Ir(piq) _{3 are} mixed by vacuum vapor deposition to form a compound SPH-2 having a thickness of 30 nm and an Ir(piq) ₃ containing 10% as an organic light-emitting layer; Then, a film having a thickness of 5 nm is formed as an electron transport layer by BCP; a film having a thickness of 20 nm is formed as a first electron injecting layer by Alq; then, lithium fluoride (LiF) is deposited on Alq as a second electron. Injecting layer; finally, metal aluminum is vapor-deposited to form a metal cathode layer, and the organic electroluminescent diode is fabricated.

When the current density of the organic electroluminescent diode is 20 mA/cm ² , the driving voltage is 8.5 V. It emits red light with a luminance of 900 cd/m ² and a quantum efficiency of 4.7%.

Embodiment 3:

The indium tin oxide (ITO) glass substrate was 40 mm × 40 mm thick and 0.7 mm thick, ultrasonically cleaned in methanol for 12 minutes, and then irradiated with ultraviolet rays (to produce ozone) for 10 minutes. The cleaned glass substrate is moved into a vacuum vapor deposition apparatus. On the surface with a transparent electrode, a DNTPD film having a thickness of 60 nm is formed, and the formed film is covered with a transparent electrode; the film formed by DNTPD is used as a hole injection layer; then a 30 nm NPB is formed on the DNTPD; The formed film is a hole transport layer; the compound SPH-3 and Ir(piq) _{3 are} mixed by vacuum vapor deposition to form a compound SPH-3 having a thickness of 30 nm and an Ir(piq) ₃ containing 10% as an organic light-emitting layer. Then, a 5 nm thin film is formed as an electron transport layer by BCP; a 20 nm thin film is formed as a first electron injection layer by Alq; then, lithium fluoride (LiF) is deposited on Alq as a second Electron injection layer; finally, metal aluminum is vapor deposited to form a metal cathode layer, and an organic electroluminescence excitation diode is fabricated.

When the current density of the organic electroluminescent diode is 20 mA/cm ² , the driving voltage is 8.5 V. It emits red light with a brightness of 880 cd/m ² and a quantum efficiency of 4.8%.

Embodiment 4:

The indium tin oxide (ITO) glass substrate was 40 mm × 40 mm thick and 0.7 mm thick, ultrasonically cleaned in methanol for 12 minutes, and then irradiated with ultraviolet rays (to produce ozone) for 10 minutes. The cleaned glass substrate is moved into a vacuum vapor deposition apparatus. On the surface with a transparent electrode, a DNTPD film having a thickness of 60 nm is formed, so that the formed film covers the transparent electrode; the film formed by DNTPD is used as a hole injection layer; then a 30 nm NPB is formed on the DNTPD; The film is a hole transport layer; the compound SPH-1 and Ir(piq) _{3 are} mixed by vacuum vapor deposition to form a compound SCH-1 having a thickness of 30 nm and an Ir(piq) ₃ containing 10% as an organic light-emitting layer; Then, a film having a thickness of 5 nm is formed as an electron transport layer by BCP; a film having a thickness of 20 nm is formed as a first electron injecting layer by Alq; then, lithium fluoride (LiF) is deposited on Alq as a second electron. Injecting layer; finally, metal aluminum is vapor-deposited to form a metal cathode layer, and the organic electroluminescent diode is fabricated.

When the organic electroluminescence diode current density is 20 mA/cm ² , the driving voltage is 8.3 V. It emits red light with a brightness of 600 cd/m ² and a quantum efficiency of 4.1%.

Embodiment 5:

The indium tin oxide (ITO) glass substrate was 40 mm × 40 mm thick and 0.7 mm thick, ultrasonically cleaned in methanol for 12 minutes, and then irradiated with ultraviolet rays (to produce ozone) for 10 minutes. The cleaned glass substrate is moved into a vacuum vapor deposition apparatus. On the surface with a transparent electrode, a DNTPD film having a thickness of 60 nm is formed to form a transparent electrode of the film cover; a film formed by DNTPD is used as a hole injection layer; then a 30 nm NPB is formed on the DNTPD; The film is a hole transport layer; the compound SCH-2 and Ir(piq) _{3 are} mixed by vacuum vapor deposition to form a compound SCH-2 having a thickness of 30 nm and an Ir(piq) ₃ containing 10% as an organic light-emitting layer; Then, a film having a thickness of 5 nm is formed as an electron transport layer by BCP; a film having a thickness of 20 nm is formed as a first electron injecting layer by Alq; then, lithium fluoride (LiF) is deposited on Alq as a second electron. Injecting layer; finally, metal aluminum is vapor-deposited to form a metal cathode layer, and the organic electroluminescent diode is fabricated.

When the current density of the organic electroluminescence diode is 20 mA/cm ² , the driving voltage is 7.8 V. It emits red light with a brightness of 800 cd/m ² and a quantum efficiency of 5.1%.

Example 6:

The indium tin oxide (ITO) glass substrate was 40 mm × 40 mm thick and 0.7 mm thick, ultrasonically cleaned in methanol for 12 minutes, and then irradiated with ultraviolet rays (to produce ozone) for 10 minutes. The cleaned glass substrate is moved into a vacuum vapor deposition apparatus. On the surface with a transparent electrode, a DNTPD film having a thickness of 60 nm is formed, so that the formed film covers the transparent electrode; the film formed by DNTPD is used as a hole injection layer; then a 30 nm NPB is formed on the DNTPD; The film is a hole transport layer; the compound SCH-3 and Ir(piq) _{3 are} mixed by vacuum vapor deposition to form a compound SCH-3 having a thickness of 30 nm and an Ir(piq) ₃ containing 10% as an organic light-emitting layer; Then, a film having a thickness of 5 nm is formed as an electron transport layer by BCP; a film having a thickness of 20 nm is formed as a first electron injecting layer by Alq; then, lithium fluoride (LiF) is deposited on Alq as a second electron. Injecting layer; finally, metal aluminum is vapor-deposited to form a metal cathode layer, and the organic electroluminescent diode is fabricated.

When the current density of the organic electroluminescence diode is 20 mA/cm ² , the driving voltage is 8.8 V. It emits red light with a brightness of 700 cd/m ² and a quantum efficiency of 7.4%.

Comparative example 1:

The indium tin oxide (ITO) glass substrate was 40 mm × 40 mm thick and 0.7 mm thick, ultrasonically cleaned in methanol for 12 minutes, and then irradiated with ultraviolet rays (to produce ozone) for 10 minutes. The cleaned glass substrate is moved into a vacuum vapor deposition apparatus. On the surface with transparent electrode, a layer of NPB with a thickness of 30 nm is formed; the formed film is a hole transport layer; the compound CBP and Ir(piq) _{3 are} mixed by vacuum vapor deposition to form a compound SCH with a thickness of 30 nm. -3 and 6% of Ir(piq) ₂ acac as an organic light-emitting layer; a thin film of 10 nm is formed as an electron transport layer by BCP; and a film having a thickness of 30 nm is formed as a first electron injection layer by Alq After that, lithium fluoride (LiF) is deposited on Alq as a second electron injecting layer; finally, metal aluminum is vapor deposited to form a metal cathode layer, thereby completing the fabrication of an organic electroluminescent diode.

When the organic electroluminescence diode current density is 20 mA/cm ² , the driving voltage is 8.7 V. It emits red light with a luminance of 1566 cd/m ² and a quantum efficiency of 7.4%.

It can be seen from the above examples that when the carbazole compound of the present invention is added to the organic light-emitting layer, the organic electroluminescent diode can surely emit red light, and the organic electroluminescent diode can be applied to a wider range. Applications.

10‧‧‧Organic electroluminescent diodes

11‧‧‧Substrate

12‧‧‧ anode layer

13‧‧‧ hole injection layer

14‧‧‧Organic hole transport layer

15‧‧‧Organic light-emitting layer

16‧‧‧Electronic transport layer

17‧‧‧Electronic injection layer

18‧‧‧ cathode layer

19‧‧‧Power supply

1 is a schematic view showing the structure of an organic electroluminescent diode of the present invention.

Figure 2 is a nuclear magnetic resonance (NMR) spectrum of SPH-1 of the present invention.

Figure 3 is a mass spectrogram of SPH-1 of the present invention.

Figure 4 is a fluorescence property analysis (UV/PL) spectrum of SPH-1 of the present invention.

Figure 5 is a nuclear magnetic resonance (NMR) spectrum of SPH-2 of the present invention.

Figure 6 is a mass spectrogram of SPH-2 of the present invention.

Figure 7 is a fluorescence property analysis (UV/PL) spectrum of SPH-2 of the present invention.

Figure 8 is a nuclear magnetic resonance (NMR) spectrum of SPH-3 of the present invention.

Fig. 9 is a mass spectrogram of SPH-3 of the present invention.

Figure 10 is a fluorescence property analysis (UV/PL) spectrum of SPH-3 of the present invention.

Figure 11 is a nuclear magnetic resonance (NMR) spectrum of SCH1-1 of the present invention.

Figure 12 is a mass spectrogram of SCH1-1 of the present invention.

Figure 13 is a fluorescence property analysis (UV/PL) spectrum of SCH1-1 of the present invention.

Figure 14 is a nuclear magnetic resonance (NMR) spectrum of SCH1-2 of the present invention.

Figure 15 is a mass spectrogram of SCH1-2 of the present invention.

Figure 16 is a fluorescence property analysis (UV/PL) spectrum of SCH1-2 of the present invention.

Figure 17 is a nuclear magnetic resonance (NMR) spectrum of SCH1-3 of the present invention.

Figure 18 is a mass spectrogram of SCHH1-3 of the present invention.

Figure 19 is a fluorescence property analysis (UV/PL) spectrum of SCH1-3 of the present invention.

Figure 20 is a graph showing the relationship between current density and driving voltage of the SPH compound of the present invention.

Figure 21 is a graph showing the relationship between the luminance and the driving voltage of the SPH compound of the present invention.

Figure 22 is a graph showing the relationship between quantum efficiency and brightness of the SPH compound of the present invention.

Figure 23 is a graph showing the relationship between the wavelength and the intensity of the SPH compound of the present invention.

Figure 24 is a graph showing the relationship between the current density and the driving voltage of the SCH compound of the present invention.

Figure 25 is a graph showing the relationship between the luminance and the driving voltage of the SCH compound of the present invention.

Figure 26 is a graph showing the relationship between quantum efficiency and brightness of the SCH compound of the present invention.

Figure 27 is a graph showing the relationship between the wavelength and the intensity of the SCH compound of the present invention.

10‧‧‧Organic electroluminescent diodes

11‧‧‧Substrate

12‧‧‧ anode layer

13‧‧‧ hole injection layer

14‧‧‧Organic hole transport layer

15‧‧‧Organic light-emitting layer

16‧‧‧Electronic transport layer

17‧‧‧Electronic injection layer

18‧‧‧ cathode layer

19‧‧‧Power supply

Claims (6)

A red phosphorescent material selected from the group consisting of the following carbazole compounds: An organic electroluminescent diode comprising: a substrate; an anode layer deposited on the surface of the substrate; and a cathode layer disposed on the anode layer opposite to one side of the substrate; An organic light-emitting layer disposed between the anode layer and the cathode layer, comprising the red phosphorescent material as described in claim 1. The organic electroluminescent diode according to claim 2, further comprising: a hole injection layer deposited on the surface of the anode layer; and an organic hole transport layer deposited on the electricity a hole is injected on the surface of the layer, and the organic light-emitting layer is deposited on the surface thereof; an electron transport layer is deposited on the surface of the organic light-emitting layer; and an electron injection layer is deposited on the surface of the electron transport layer; A cathode layer is deposited on the surface of the electron injecting layer. Organic electroluminescence 2 as described in claim 2 or 3 A polar body in which the substrate is made of transparent glass or plastic. The organic electroluminescent diode of claim 2, wherein the anode is transparent. The organic electroluminescent diode of claim 4, wherein the anode is transparent.