CN112993176A - TADF material-based white light electroluminescent device and preparation method thereof - Google Patents

TADF material-based white light electroluminescent device and preparation method thereof Download PDF

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CN112993176A
CN112993176A CN202011617984.XA CN202011617984A CN112993176A CN 112993176 A CN112993176 A CN 112993176A CN 202011617984 A CN202011617984 A CN 202011617984A CN 112993176 A CN112993176 A CN 112993176A
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substrate
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吕萌萌
乔泊
赵谡玲
徐征
宋丹丹
范玲
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Beijing Jiaotong University
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    • H10K50/11—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers
    • H10K50/12—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers comprising dopants
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Abstract

The invention provides a TADF material-based white light electroluminescent device and a preparation method thereof. The device can effectively reduce the driving voltage of the device, realizes white light emission by simultaneous luminescence of the blue TADF material and the red phosphorescent material complementary with the blue light, has simple structure, can obtain high device efficiency, reduces the starting voltage and effectively improves the performance of the device.

Description

TADF material-based white light electroluminescent device and preparation method thereof
Technical Field
The invention relates to the field of OLED devices, in particular to a white light electroluminescent device based on TADF materials.
Background
Organic Light-Emitting Diodes (OLEDs), which are devices capable of directly converting electrical energy into optical energy, employ Organic molecular materials as Light-Emitting layer films, and can generate a strong electro-optic effect at low driving voltages. OLEDs have the advantages of lightness, thinness, surface emission, self-luminescence, easy processing, large-area preparation and flexibility, and have great application prospects in the fields of flat panel display and solid state lighting. However, for most white OLED devices today, the highest Power efficiency (Power efficiency) still lingers between 40 and 60 lumens per watt (lm · W)-1) This figure is far from its theoretical maximum lumen efficiency of 249 lumens per watt. Therefore, for improving the performance of the device, a larger digging space is still left in the aspect of the device structure. For this purpose, many key issues need to be addressed in the design and fabrication of devices.
In recent years, Thermally Activated Delayed Fluorescence (TADF) materials have advanced very rapidly, and are considered to be third generation OLED emitters. The material with blue heat activated delayed fluorescence (TADF) has the following three characteristics: (1) because the single-state energy and the three-state energy of the material are very different, the material is beneficial to realizing high three-state energy; (2) can have high efficiency; (3) triplet excitons can be trapped, so the novel blue Thermally Activated Delayed Fluorescence (TADF) material has great potential to realize high-performance hybrid WOLEDs.
In addition, since the organic phosphorescent material also has the ability to utilize both singlet and triplet states, 100% internal quantum efficiency has been achieved. However, unlike internal quantum efficiency, light extraction efficiency is still low. For most OLED devices, the light extraction efficiency is still generally below 30%. The main causes of this phenomenon are refractive index mismatch between the respective organic layers inside the OLED device, absorption of emitted light on the electrodes, and the like. In addition, a large amount of unnecessary energy loss in the electro-optical conversion process is also an important reason for the generally low efficiency of the device. Energy levels among all organic functional layers are not matched, so that higher turn-on voltage is brought, and the performance of the device is also seriously influenced. Although many articles in the past have reported various methods for reducing the energy loss and the driving voltage of the device, the efficiency of the device is not substantially improved. The reason is mainly because most of the work is mainly focused on how to modify the materials of the electrode, the carrier transport layer and the carrier injection layer, and the design of the organic light emitting layer is neglected.
Therefore, the blue TADF material and the red phosphorescent material as the guest are put into the system of the interface exciplex, which is very helpful to the improvement of the efficiency and the improvement of the structure of the device.
Disclosure of Invention
The invention aims to provide a white light electroluminescent device based on TADF material, which has high efficiency, high color rendering index and good color stability.
The technical scheme of the invention is as follows:
a white light electroluminescent device based on a TADF material sequentially comprises an ITO glass substrate layer, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, a cathode modification layer and a metal cathode layer from inside to outside.
Preferably, the thickness of the ITO glass substrate layer is 135 nm, the thickness of the hole injection layer is 40nm, the thickness of the hole transport layer is 40nm, the thickness of the light emitting layer is 40nm, the thickness of the electron transport layer is 50nm, the thickness of the cathode modification layer is 1nm, and the thicknesses of the metal cathode layers are 120nm respectively.
Preferably, the ITO glass substrate layer is used as a substrate and an anode of the white light electroluminescent device, the ITO glass substrate layer is made of ITO conductive glass, the hole injection layer is PEDOT: PSS, the hole transport layer is PVK, the light emitting layer is made of a host material and an object material, the electron transport layer is PO-T2T, the cathode modification layer is LiF, and the metal cathode layer is Al.
Preferably, the host material is 3,3 ' -bis (9H-carbazol-9-yl) -1,1 ' -biphenyl, i.e. m-CBP, and the guest material is composed of a blue TADF material and a red phosphorescent material, wherein the blue TADF material is 10- (4- (4,6-diphenyl-1,3,5-triazin-2-yl) phenyl) -10H-spiro [ acridine-9,9' -fluorene]I.e., SpiroAC-TRZ, the red phosphor material is (acetylacetone) bis (2-methyldibenzo [ F, H ]]Quinoxaline) iridium, i.e. Ir(MDQ)2acac。
Preferably, the ratio of the host material, the blue TADF material and the red phosphorescent material is m-CBP: SpiroAC-TRZ: ir (MDQ)2acac＝1:(10％-25％):(0.2％-0.8％)。
A preparation method of a TADF material-based white light electroluminescent device comprises the following steps:
the method comprises the following steps: the ITO conductive glass is used as a substrate and an anode of a device, and is respectively soaked in glass beakers of neutral cleaning solution, deionized water and alcohol after being cut and etched, wherein the deionized water and the alcohol need to be respectively replaced once, the glass beakers are cleaned in an ultrasonic cleaning pool for 30 minutes each time the cleaning solution is replaced, and then the alcohol on the surface of the ITO conductive glass is dried by using 99.5 percent common nitrogen for standby;
step two: introducing oxygen into the cleaned ITO glass in a plasma processor for 90 s;
step three: spin-coating PEDOT on the ITO glass treated in the second step, wherein PSS stock solution is used as a hole injection layer and plays a role in lubricating a substrate of the ITO glass; then placing the substrate on a platform at 120 ℃ for annealing for 20 minutes to form a substrate;
step four: transferring the substrate in the third step into a spin-coating glove box, spin-coating a hole transport layer on the substrate, and then annealing the substrate on a heating platform at 150 ℃ for 30 minutes;
step five: after the substrate in the fourth step is cooled to room temperature, continuing to spin a layer of luminescent layer, and then putting the luminescent layer on a heating platform at the temperature of 80 ℃ for annealing for 20 minutes;
step six: after the substrate in the step five is cooled to room temperature, transferring the substrate into a multi-source organic small molecule vacuum evaporation system, and vacuumizing until the pressure of a chamber is lower than 9 multiplied by 10-5After Pa, a layer of PO-T2T with the thickness of 50nm is evaporated and used as an electron transport layer under the condition of keeping the pressure;
step seven: evaporating a layer of LiF with the thickness of 1nm on the substrate in the step six to be used as a cathode modification layer, stopping heating, cooling the evaporation source to be below 60 ℃ in the vacuum state, filling nitrogen in a glove box into the evaporation chamber to normal pressure, and taking out the substrate;
step eight: replacing the substrate in the seventh step with a special mask plate for evaporating metal electrodes, placing the mask plate into a multi-source metal vacuum evaporation system, and vacuumizing until the pressure of a cavity is lower than 9 multiplied by 10-5After Pa, a layer of 120nm aluminum is evaporated under the pressure to be used as a metal cathode;
step nine: and (3) after the film coating is finished, keeping the vacuum state until the temperature of the evaporation source is cooled to be below 60 ℃, filling nitrogen in a glove box into the evaporation chamber to normal pressure, and taking out the substrate to obtain the TADF material-based white light electroluminescent device prepared by the solution method.
Preferably, in the third step, the hole injection layer (PEDOT: PSS stock solution) is filtered by an aqueous filter head before being spin-coated, the filter head specification is 0.25 μm, the spin-coating condition parameter of the hole injection layer (PEDOT: PSS stock solution) is 4000rps (revolutions per minute), and the time is set to be 40 seconds.
Preferably, in the fourth step, the hole transport layer material is poly (9-vinylcarbazole) (PVK), the concentration of the prepared solution is 8mg/mL, the spin coating condition parameter is 2000rps (revolutions per minute), and the time is set to 40 seconds.
Preferably, in the fifth step, the solution of the host material m-CBP in the light-emitting layer is prepared to have a concentration of 10mg/mL, the guest material SpiroAC-TRZ is prepared to have a concentration of 10mg/mL, and the guest material Ir (MDQ)2The concentration of acac is 2mg/mL, and the doping concentration ratio of the three in the luminous layer is m-CBP: SpiroAC-TRZ: ir (MDQ)2acac＝1:15wt％：0.06wt％。
Preferably, in the sixth step, the evaporation speed of PO-T2T is
Figure RE-GDA0003033208830000041
In the eighth step, the evaporation speed of the metal aluminum is
Figure RE-GDA0003033208830000042
The growth rate and the thickness of the film are monitored by a film thickness meter, the operations of the fifth step to the eighth step are all carried out in a glove box, and the atmosphere of the glove box is controlled to be water content<1ppm, oxygen content<1ppm。
The invention has the beneficial effects that:
1. the maximum brightness of the device provided by the invention reaches 7093cd/m2With a color rendering index as high as 80, the device maximum current efficiency is 30.5cd/a, the CIE coordinates at maximum luminance are (0.372,0.375), and at 100cd and 1000cd, the color coordinates are only shifted (0.013,0.006), showing excellent spectral stability.
2. The device provided by the invention adopts an interface exciplex system, which is beneficial to reducing the transmission barrier of electrons from the ETL to the EML layer, thereby reducing the turn-on voltage of the device.
3. In the method provided by the invention, the spin coating annealing and the subsequent preparation process of the luminescent layer are completed in a glove box, so that the pollution and harm caused by organic solvents are avoided, and the preparation process is green and environment-friendly.
Drawings
Fig. 1 is a structural diagram of a white light electroluminescent device based on TADF material according to an embodiment of the present invention;
fig. 2 is a schematic diagram of an electroluminescence spectrum of a prepared white light electroluminescence device provided by an embodiment of the invention;
fig. 3 is a schematic diagram of a current density-voltage-luminance characteristic curve of a prepared device according to an embodiment of the present invention;
fig. 4 is a schematic diagram of a color coordinate condition of a device at maximum brightness according to an embodiment of the present invention;
fig. 5 is a schematic diagram of a designed photoluminescence spectrum of the exciplex according to an embodiment of the present invention.
Fig. 6 is a schematic diagram of a current density-current efficiency characteristic curve of a fabricated device according to an embodiment of the present invention.
Detailed Description
The present invention is further described below in conjunction with the following figures and specific examples so that those skilled in the art may better understand the present invention and enable its practice, and the embodiments of the present invention are not limited thereto.
As shown in FIG. 1, a TADF material-based white light electroluminescence deviceThe structure of the device is characterized in that an ITO (Indium Tin Oxides) glass substrate is used as a substrate and an anode of the device, a hole injection layer is firstly coated on the ITO glass substrate in a spin mode, PEDOT (Poly- (3, 4-ethylene dioxythiophene) polytyrene sulfonate Poly (3, 4-ethylenedioxythiophene) -Poly (styrenesulfonic acid)) is used as the hole injection layer, then the hole injection layer is transferred into a glove box, a 40nm hole transport layer is coated on the hole transport layer in a spin mode, PVK (Poly (9-vinyl carbazole) is used as the hole transport layer, a 40nm light emitting layer is coated on the hole transport layer after annealing is carried out on a heating platform at the temperature of 150 ℃ for 30 minutes, the host material used for the light emitting layer is 3,3 '-bis (9H-carbazole-9-yl) -1, 1' -biphenyl (m-CBP), the object material is blue TADF material 10- (4- (4), 6-diphenyl-1,3,5-triazin-2-yl) phenyl) -10H-spiro [ acridinine-9, 9' -fluorone](SpiroAC-TRZ) and a red phosphor material (acetylacetone) bis (2-methyldibenzo [ F, H)]Quinoxaline) Iridium (Ir (MDQ)2acac) is annealed on a heating platform at the temperature of 80 ℃ for 20 minutes, then the mixture is transferred into a glove box for evaporation, a 50nm electron transport layer is deposited on the luminescent layer, and the electron transport layer adopts PO-T2T (2,4,6-Tris [3- (diphenylphosphinyl) phenyl)]-1,3,5-triazine2,4, 6-tris [3- (diphenylphosphinoxy) phenyl]-1,3, 5-triazole Synonym), then depositing a 1nm cathode modification layer on the electron transport layer, wherein the cathode modification layer adopts LiF, and finally evaporating a layer of 120nm aluminum on the cathode modification layer as a metal electrode to finally obtain a metal electrode with a total light-emitting area of 9mm2The device of (1).
In the preparation of the above TADF based white electroluminescent devices, the ITO glass substrates used in the practice were of laboratory design and were manufactured by Hunan City science and technology, south China, PEDOT: PSS, m-CBP available from Saibao Laite, SpiroAC-TRZ, Ir (MDQ)2acac was purchased from Taiwan corporation of Imperial technologies, and the above materials were used without purification. The J-V-L curve and the electroluminescence spectrum were measured with a power supply (Keithley2410), a spectroradiometer (CR-250) and an optical power meter. Transient Photoluminescence (PL) was measured in an atmospheric environment using an apparatus FluoroCube01-N1 manufactured by Horiba, Inc.
The specific preparation method of the white light electroluminescent device comprises the following steps:
the method comprises the following steps: ITO conductive glass is used as a substrate and an anode of a device, and is respectively soaked in glass beakers of neutral cleaning solution, deionized water and alcohol after being cut and etched, wherein the deionized water and the alcohol need to be respectively replaced once, the glass beakers are cleaned in an ultrasonic cleaning pool for 30 minutes each time the cleaning solution is replaced, and then the alcohol on the surface of the ITO is dried for standby by using 99.5 percent common nitrogen;
step two: introducing oxygen into the cleaned ITO glass in a plasma processor for 90 s;
step three: spin-coating PEDOT on the ITO glass treated in the second step, wherein PSS stock solution is used as a hole injection layer and plays a role in lubricating a substrate of the ITO glass; filtering with water-based filter head before spin-coating hole injection layer (PEDOT: PSS stock solution), wherein the filter head specification is 0.25 μm, the spin-coating parameter is set to 4000 rpm, and the time is set to 40 seconds; annealing for 20 minutes on a heating platform at 120 ℃ after spin coating to form a substrate;
step four: transferring the substrate in the third step into a glove box for spin coating, spin coating a hole transport layer, and then annealing on a heating platform at 150 ℃ for 30 minutes, wherein the hole transport layer is made of poly (9-vinylcarbazole), namely PVK, the concentration of the prepared solution is 8mg/mL, the spin coating parameter is set to 2000 rpm, and the time is set to 40 seconds;
step five: after the substrate in the fourth step is cooled to room temperature, continuing to spin a layer of luminescent layer, and then putting the luminescent layer on a heating platform at the temperature of 80 ℃ for annealing for 20 minutes; the host material of the luminescent layer is m-CBP, and the guest material is TADF material spiroAC-TRZ and phosphorescent material Ir (MDQ)2acac, three are all dissolved in chlorobenzene, firstly, each material is dissolved in chlorobenzene, the dissolution concentration is respectively 10mg/mL, 10mg/mL and 2mg/mL, then, the three are doped and mixed according to the mass ratio, the middle time interval is more than four hours, and the doping concentration ratio of the three in the luminous layer is m-CBP: SpiroAC-TRZ: ir (MDQ)2acac＝1:15wt％：0.06wt％；
Step six: after the substrate in the step five is cooled to room temperature, transferring the substrate into a multi-source organic small molecule vacuum evaporation system, and vacuumizing to the pressure of a cavityAfter a force of less than 9X 10-5Pa, a layer of PO-T2T with a thickness of 50nm is subsequently evaporated as an electron transport layer while maintaining this pressure, at an evaporation rate of
Figure RE-GDA0003033208830000071
An interfacial exciplex can be formed between PO-T2T and m-CBP.
Step seven: evaporating a layer of LiF with the thickness of 1nm as a cathode modification layer on the substrate in the step six, wherein the evaporation rate is
Figure RE-GDA0003033208830000081
After heating is stopped, in the vacuum state, after the temperature of the evaporation source is cooled to be below 60 ℃, filling nitrogen in the glove box into the evaporation chamber to normal pressure, and taking out the substrate;
step eight: replacing the substrate in the seventh step with a special mask plate for evaporating a metal electrode, putting the substrate into a multi-source metal vacuum evaporation system, vacuumizing until the pressure of a cavity is lower than 9 x 10 < -5 > Pa, and evaporating a layer of 120nm aluminum serving as a metal cathode under the pressure, wherein the evaporation rate is
Figure RE-GDA0003033208830000082
The growth speed and the thickness of the film are monitored by a film thickness meter;
step nine: and (3) after the film coating is finished, keeping the temperature of the evaporation source in the vacuum state to be cooled to be below 60 ℃, filling nitrogen in a glove box into the evaporation chamber to normal pressure, and taking out the substrate to obtain the TADF material-based white light electroluminescent device prepared by the solution method.
Wherein, the operations of the fifth step to the eighth step are all carried out in a glove box, and the atmosphere of the glove box is controlled to be that the water content is less than 1ppm and the oxygen content is less than 1 ppm.
The structure of the finally obtained white light electroluminescent device based on the TADF material is as follows: IT0/PEDOT PSS/PVK/m-CBP 15 wt% SpiroAC-TRZ: 0.06% Ir (MDQ)2acac/PO-T2T(50nm)/LiF(1nm)/Al(120nm)。
As shown in fig. 2, the electroluminescence spectrum of the white light electroluminescent device prepared by the present invention has two peaks, which respectively correspond to sky blue light of 493 nm and red light of 600 nm, which is complementary to sky blue light.
As shown in FIG. 3, the device prepared by the invention has a starting voltage of 4.3V and a maximum brightness of 7093cd/m2。
As shown in fig. 4, the color coordinates at maximum luminance of the device prepared by the present invention are (0.3724, 0.375).
As shown in fig. 5, the mass ratio of the hole type transport host material m-CBP to the electron type transport material PO-T2T is 1; 1, the photoluminescence spectrum of the mixed substances is obviously widened and red-shifted, which shows that an exciplex is formed between the substances, and the structure can reduce the potential barrier of electrons between the ETL and the EML, and can be recombined with holes at the interface to form excitons, thereby reducing the lighting voltage of the device. As can be seen from fig. 4, the white light device is obtained by doping the red phosphorescent material on the basis of the blue TADF material. The maximum current efficiency, external quantum efficiency and maximum brightness of the device are respectively 33.2cd/A, 15.7 percent and 7093cd/m2。
As shown in FIG. 6, the current efficiency of the device prepared by the present invention was 33.2cd/A at the maximum.
Those of ordinary skill in the art will understand that: the drawings are merely schematic representations of one embodiment, and the flow charts in the drawings are not necessarily required to practice the present invention.

Claims (10)

1. A white light electroluminescent device based on a TADF material is characterized by sequentially comprising an ITO glass substrate layer, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, a cathode modification layer and a metal cathode layer from inside to outside.
2. The TADF material-based white light electroluminescent device according to claim 1, wherein the thickness of the ITO glass substrate layer is 135 nm, the thickness of the hole injection layer is 40nm, the thickness of the hole transport layer is 40nm, the thickness of the light-emitting layer is 40nm, the thickness of the electron transport layer is 50nm, the thickness of the cathode modification layer is 1nm, and the thickness of the metal cathode layer is 120nm, respectively.
3. The white light electroluminescent device based on the TADF material as claimed in claim 1, wherein the ITO glass substrate layer is used as a substrate and an anode of the white light electroluminescent device, the ITO glass substrate layer is made of ITO conductive glass, and the hole injection layer is PEDOT: the PSS comprises a hole transport layer made of PVK, a light-emitting layer made of a host material and a guest material, an electron transport layer made of PO-T2T, a cathode modification layer made of LiF, and a metal cathode layer made of A1.
4. The white light electroluminescent device based on TADF material of claim 3, wherein the host material is 3,3 ' -bis (9H-carbazol-9-yl) -1,1 ' -biphenyl (m-CBP), and the guest material is composed of a blue TADF material and a red phosphorescent material, wherein the blue TADF material is 10- (4- (4,6-diphenyl-1,3,5-triazin-2-y 1) phenyl) -10H-spiro [ acridine-9,9' -fluoroene ™ ]]Namely spiroAC-TRZ, and the red phosphor material is (acetylacetone) bis (2-methyl dibenzo [ F, H ]]Quinoxaline) iridium, i.e. Ir (MDQ)2acac。
5. The TADF material-based white light electroluminescent device according to claim 4, wherein the ratio of the host material, the blue TADF material and the red phosphorescent material is m-CBP, SpiroAC-TRZ, Ir (MDQ)2acac＝1∶(10％-25％)∶(0.2％-0.8％)。
6. A preparation method of a TADF material-based white light electroluminescent device is characterized by comprising the following steps:
the method comprises the following steps: the ITO conductive glass is used as a substrate and an anode of a device, and is respectively soaked in glass beakers of neutral cleaning solution, deionized water and alcohol after being cut and etched, wherein the deionized water and the alcohol need to be respectively replaced once, the glass beakers are cleaned in an ultrasonic cleaning pool for 30 minutes each time the cleaning solution is replaced, and then the alcohol on the surface of the ITO conductive glass is dried by using 99.5 percent common nitrogen for standby;
step two: introducing oxygen into the cleaned ITO glass in a plasma processor for 90 s;
step three: and D, spin-coating PEDOT on the ITO glass processed in the step two: the PSS stock solution is used as a hole injection layer and plays a role in lubricating the substrate of the ITO glass; then placing the substrate on a platform at 120 ℃ for annealing for 20 minutes to form a substrate;
step four: transferring the substrate in the third step into a spin-coating glove box, spin-coating a hole transport layer, and then annealing for 30 minutes on a heating platform at 150 ℃;
step five: after the substrate in the fourth step is cooled to room temperature, continuing to spin a layer of luminescent layer, and then putting the luminescent layer on a heating platform at the temperature of 80 ℃ for annealing for 20 minutes;
step six: after the substrate in the step five is cooled to room temperature, transferring the substrate into a multi-source organic small molecule vacuum evaporation system, and vacuumizing until the pressure of a chamber is lower than 9 multiplied by 10-5After Pa, a layer of PO-T2T with the thickness of 50nm is evaporated and used as an electron transport layer under the condition of keeping the pressure;
step seven: evaporating a layer of LiF with the thickness of 1nm on the substrate in the step six to be used as a cathode modification layer, stopping heating, cooling the evaporation source to be below 60 ℃ in the vacuum state, filling nitrogen in a glove box into the evaporation chamber to normal pressure, and taking out the substrate;
step eight: replacing the substrate in the seventh step with a special mask plate for evaporating metal electrodes, placing the mask plate into a multi-source metal vacuum evaporation system, and vacuumizing until the pressure of a cavity is lower than 9 multiplied by 10-5After Pa, a layer of 120nm aluminum is evaporated under the pressure to be used as a metal cathode;
step nine: and (3) after the film coating is finished, keeping the vacuum state until the temperature of the evaporation source is cooled to be below 60 ℃, filling nitrogen in a glove box into the evaporation chamber to normal pressure, and taking out the substrate to obtain the TADF material-based white light electroluminescent device prepared by the solution method.
7. The method according to claim 6, wherein the step three is carried out by filtering with an aqueous filter before the hole injection layer (PEDOT: PSS stock solution) is spin-coated, the filter specification is 0.25 μm, the spin-coating condition parameter of the hole injection layer (PEDOT: PSS stock solution) is 4000rps (revolutions per minute), and the time is set to 40 seconds.
8. The method according to claim 6, wherein in the fourth step, the hole transport layer material is poly (9-vinylcarbazole), PVK, the concentration of the prepared solution is 8mg/mL, the spin-coating condition parameter is 2000rps (revolutions per minute), and the time is set to 40 seconds.
9. The method for preparing a TADF material-based white light electroluminescent device according to claim 6, wherein in the fifth step, the concentration of the solution of the host material m-CBP in the luminescent layer is 10mg/mL, the concentration of the guest material SpiroAC-TRZ is 10mg/mL, and the concentration of the guest material Ir (MDQ)2The concentration of acac is 2mg/mL, and the doping concentration ratio of the three in the light-emitting layer is m-CBP: SpiroAC-TRZ: Ir (MDQ)2acac＝1∶15wt％∶0.06wt％。
10. The method for preparing a TADF material-based white light electroluminescent device according to claim 6, wherein in the sixth step, the evaporation speed of PO-T2T is
Figure FDA0002873100950000031
In the eighth step, the evaporation speed of the metal aluminum is
Figure FDA0002873100950000032
The growth speed and the thickness of the film are monitored by a film thickness meter, the operations of the fifth step to the eighth step are all carried out in a glove box, and the atmosphere of the glove box is controlled to be that the water content is less than 1ppm and the oxygen content is less than 1 ppm.
CN202011617984.XA 2020-12-30 2020-12-30 TADF material-based white light electroluminescent device and preparation method thereof Pending CN112993176A (en)

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CN104409661A (en) * 2014-11-07 2015-03-11 南京邮电大学 Complementary-color phosphorescence white light OLED (organic light emitting diode) and preparation method thereof
CN109817818A (en) * 2019-01-31 2019-05-28 云谷（固安）科技有限公司 A kind of organic electroluminescence device and display device
CN109817836A (en) * 2017-11-18 2019-05-28 昆山国显光电有限公司 Organic electroluminescence device

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CN104409661A (en) * 2014-11-07 2015-03-11 南京邮电大学 Complementary-color phosphorescence white light OLED (organic light emitting diode) and preparation method thereof
CN109817836A (en) * 2017-11-18 2019-05-28 昆山国显光电有限公司 Organic electroluminescence device
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