A green light organic electroluminescent device

An electroluminescence, electromechanical technology, applied in the field of organic electroluminescence devices, can solve the problems of high cost, high doping concentration, low energy of green OLED light-emitting layer, etc., to improve efficiency, improve device efficiency and life, improve excitation The effect of sub-utilization

Active Publication Date: 2020-07-17
KUNSHAN NEW FLAT PANEL DISPLAY TECH CENT
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] Therefore, the technical problem to be solved by the present invention lies in the problems of low energy, high doping concentration, and high cost of the green OLED light-emitting layer in the prior art, and further provides a green organic electroluminescent device, which uses thermally activated delayed fluorescence material as the main material, using The energy transfer method reduces the doping concentration of the dye, thereby improving the life and efficiency of the device

Method used

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  • A green light organic electroluminescent device
  • A green light organic electroluminescent device
  • A green light organic electroluminescent device

Examples

Experimental program
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Effect test

Embodiment 1

[0070] Such as image 3 As shown, a green light organic electroluminescent device provided by the present invention includes a substrate, and a first electrode layer 01, a light emitting layer 04, and a second electrode layer 07 sequentially formed on the substrate. The first electrode A first organic functional layer is arranged between the layer 01 and the light-emitting layer 04, and a second organic functional layer is arranged between the light-emitting layer 04 and the second electrode layer 07. The first organic functional layer is a hole injection layer 02 and / or a hole transport layer 03, and the second organic functional layer is an electron transport layer 05 and / or an electron injection layer 06.

[0071] The light-emitting host materials of the device of this embodiment are thermally activated delayed fluorescent materials and hole-type transport materials doped or not doped with hole-type transport materials, and the mass ratio of the thermally activated delayed fluo...

Embodiment 2

[0081] The light-emitting devices of device 2 to device 5 have the same structure as the light-emitting device of device 1, except that the doping concentration of the green phosphorescent dye is different. Its structure is as follows:

[0082] ITO / NPB(40nm) / TCTA(10nm) / Formula 2-1: 0.5~5wt% Ir(ppy) 2 (acac)(20nm) / Bp hen(40nm) / LiF(5nm) / Al

[0083] Table 3 Performance test results of device 2 to device 5

[0084]

[0085] The performance of the light-emitting device of device 2 to device 5 was tested, as shown in Table 3, at 5000cd / m 2 Under brightness, as the doping concentration of the dye increases, the current efficiency of the device also increases. This is because the long-range Energy transfer improves the exciton utilization rate, which in turn improves the device efficiency.

Embodiment 3

[0087] The light-emitting devices of devices 6 to 10 have the same structure as the light-emitting device of Example 1, except that the host material of the light-emitting layer 06 is different. Its structure is as follows:

[0088] ITO / NPB(40nm) / TCTA(10nm) / host material: 3wt% Ir(ppy) 2 (acac)(20nm) / Bp hen(40nm) / LiF(5nm) / Al

[0089] Table 4 Performance test results of device 6 to device 10

[0090]

[0091] The performance of the light-emitting device from device 6 to device 10 is tested, as shown in Table 4, at 5000cd / m 2 Under brightness, different thermally activated delayed fluorescent materials and different hole-type transport materials are co-evaporated. Although the doping ratio is different, the device performance shows low driving voltage and high efficiency, indicating the thermal activation delay protected by the present invention Fluorescence: The host material composed of hole-type transport materials has universality, and its devices have high-efficiency performance a...

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Abstract

The invention discloses a green organic electroluminescent device, which comprises a substrate, and a first electrode layer, a light-emitting layer and a second electrode layer sequentially formed on the substrate, the light-emitting layer includes a host material and a green phosphorescent dye, The host material is a thermally activated delayed fluorescent material and a hole-type transport material doped or not doped with a hole-type transport material, and the mass ratio of the thermally activated delayed fluorescent material to the hole-type transport material is (0.1-100 %): (99.9-0%), the doping ratio of the green phosphorescent dye in the light-emitting layer is 0.5-10wt%. The present invention uses energy transfer to reduce triplet-triplet annihilation (TTA), improve exciton utilization, and then improve device efficiency and life; ΔE of the present invention ST Small (<0.3eV), this type of electron acceptor has good stability, and the torsion angle between the acceptor and the donor is small, the radiative transition rate is high, and the singlet S of thermally activated delayed fluorescent material (TADF) 1 than the common host singlet S 1 Low, effectively reducing the device drive voltage.

Description

Technical field [0001] The present invention relates to the technical field of organic electroluminescence devices, in particular to a green light organic electroluminescence device that uses thermally activated delayed fluorescent materials and hole-type transport materials as luminescent host materials. Background technique [0002] After nearly 30 years of development, organic electroluminescent devices (English full name Organic Light Emitting Device, referred to as OLED) as the next generation of lighting and display technology, with wide color gamut, fast response, wide viewing angle, pollution-free, high contrast, The advantages of planarization have already been applied to a certain extent in lighting and display. [0003] Organic electroluminescent devices usually include a cathode, a light-emitting layer and an anode. The light-emitting layer includes a luminescent host material and a luminescent dye, such as figure 1 As shown, under the condition of electro-excited excit...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01L51/00H01L51/50
CPCH10K85/60H10K50/12
Inventor 赵菲段炼张东东刘嵩
Owner KUNSHAN NEW FLAT PANEL DISPLAY TECH CENT
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