A kind of organic electroluminescence device and preparation method thereof

An electroluminescent device, organic technology, applied in the direction of organic light-emitting devices, organic light-emitting device parameters, electric solid-state devices, etc.

Active Publication Date: 2017-09-29
BEIJING VISIONOX TECH +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The researchers proposed to use triplet state quenching to generate singlet states in fluorescent devices to improve the efficiency of fluorescent devices, but the theoretical maximum external quantum efficiency of this method is only 62.5%, which is far lower than that of phosphorescent materials.

Method used

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  • A kind of organic electroluminescence device and preparation method thereof
  • A kind of organic electroluminescence device and preparation method thereof
  • A kind of organic electroluminescence device and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0250] In this example, yellow light-emitting devices with different doping concentrations of fluorescent dyes were prepared, and these devices have such as image 3 structure shown. The light-emitting layer contains a host material (Host 1) and a fluorescent doped dye (YD 1), in which the Host1 material is the first type of host material, and the first triplet state of its (n-π) excited state is slightly smaller than that of the CT excited state The first triplet state (0.1eV) of the state, the singlet energy level of YD1 is 2.2 eV, which is lower than the singlet energy level of Host 1. The structural formulas of Host 1 and YD 1 are as follows:

[0251] ,

[0252] 2-7, YD1

[0253] The device structure of this embodiment is as follows:

[0254] ITO (150nm) / NPB (40nm) / Host 1: (0.01%, 0.5%, 1.0%, 5%): YD 1 (30nm) / Alq 3 (20nm) / LiF(0.5nm) / Al(150nm)

[0255] Wherein, the percentages in parentheses before YD1 indicate different doping concentrations of fluorescent dyes, ...

Embodiment 2

[0274] In this example, red light-emitting devices with different doping concentrations of fluorescent dyes were prepared, and these devices had such image 3 structure shown. The light-emitting layer contains a host material (Host2) and a fluorescent dopant dye (RD 1). The energy level difference between the triplet state of the CT excited state of Host2 and the triplet state of the (n-π) excited state is very large (1.3 eV), and the second triplet state of the (n-π) excited state is higher than the first triplet state of the CT excited state. A singlet state, the singlet energy level of RD1 is 2.0 eV, and the singlet energy level of RD1 is lower than that of Host 2. The structural formulas of Host 2 and RD1 are as follows:

[0275] ,

[0276] 3-6, RD1

[0277] Prepare an organic electroluminescence device in the same manner as in Example 1 above, and the structure of the light-emitting device is as follows:

[0278] ITO (150nm) / NPB (40nm) / Host 2: (0.01%, 0.5%, 1.0%,...

Embodiment 3

[0289] In order to test the influence of the host material of the present invention on the performance of the organic electroluminescent device, this example prepared an organic electroluminescent device in the same manner as in Example 1 above. The structure of the light emitting device is as follows:

[0290] ITO (150nm) / NPB (40nm) / host material: 0.5% YD 1 (30nm) / Bphen (20nm) / LiF (0.5nm) / Al (150nm).

[0291] The properties of the organic electroluminescent device are shown in Table 3 below:

[0292] table 3

[0293]

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Abstract

The invention discloses an organic electroluminescent device and a preparation method thereof. The host material of the light-emitting layer of the organic electroluminescent device is a material in which the triplet energy level of the CT excited state is higher than the triplet energy level of the n-π excited state, and the difference is between 0 and 0.3 eV; or, the light-emitting layer The host material is a material in which the triplet energy level of the CT excited state is higher than the triplet energy level of the n-π excited state, and the difference is more than 1.0 eV, and the second of the n-π excited state of the host material The difference between the triplet energy level and the first singlet energy level of the CT excited state is -0.1~0.1 eV; the luminescent dye is a fluorescent dye. The organic electroluminescent device of the present invention utilizes the new host material of the luminescent layer, can fully utilize the triplet state generated in the luminescent layer, realizes 100% luminous efficiency in the fluorescent device, and reduces cost without using noble metals.

Description

technical field [0001] The invention belongs to the field of organic electroluminescent devices, and in particular relates to an organic electroluminescent device and a preparation method thereof. Background technique [0002] Under electro-excitation conditions, organic electroluminescent devices will produce 25% singlet states and 75% triplet states. Traditional fluorescent materials can only utilize 25% of the singlet excitons due to spin prohibition, so the external quantum efficiency is only limited to within 5%. Almost all triplet excitons can only be lost as heat. To improve the efficiency of organic electroluminescent devices, triplet excitons must be fully utilized. [0003] In order to utilize triplet excitons, researchers have proposed many methods. Most notable is the utilization of phosphorescent materials. Due to the introduction of heavy atoms, the phosphorescent material has a spin-orbit coupling effect, so it can make full use of 75% of the triplet state...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01L51/52H01L51/54H01L51/56
CPCH10K50/11H10K2101/40H10K71/00C09K11/025C09K11/06H10K85/611H10K2101/00H10K85/624H10K85/633H10K85/656H10K85/6572H10K85/654H10K85/622H10K85/636H10K85/653H10K85/657H10K85/6565H10K50/15H10K50/16H10K85/655H10K2101/10C09K2211/1007C09K2211/1011C09K2211/1029C09K2211/1088
Inventor 邱勇段炼张东东张国辉
Owner BEIJING VISIONOX TECH
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