Organic Electroluminescent Device Host Material Efficiency Lifetime

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Solution Overview

Problem

Current organic electroluminescent devices, particularly phosphorescent OLEDs, face challenges with non-saturated blue color, short device lifetime, high operating voltage, and efficiency roll-off at high brightness, limiting their commercialization and performance.

Innovation Solution

An electroluminescent device comprising a first compound with a specific structure and a second compound, where the organic layer includes these compounds to improve charge transport and exciton manipulation, enhancing internal quantum efficiency and extending device lifetime while reducing voltage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If phosphorescent emitters are used in OLEDs, then internal quantum efficiency can reach 100%, but device lifetime is short and operating voltage is high

Engineering Contradiction:

Improveinternal quantum efficiencyVSAvoiddevice lifetime

Core Design Contradiction:

Use of energy by moving objectVSDuration of action of stationary object

Solution Approach 1:

The patent modifies molecular parameters of the host compounds by introducing specific heteroaryl groups (triazine, pyrimidine, pyridine rings) and adjusting substituent positions to optimize the balance between efficiency and lifetime. This changes the electronic and steric parameters of the molecules to achieve better device performance

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses composite host material systems combining compounds with different functions - one compound primarily for charge transport and another for exciton management. This composite approach allows simultaneous optimization of efficiency, lifetime, and voltage characteristics that single materials cannot achieve

Inventive Principle:

Principle #40Composite materials

2Use of energy by moving object

If phosphorescent emitters are used in OLEDs, then internal quantum efficiency can reach 100%, but efficiency roll-off occurs at high brightness

Engineering Contradiction:

Improveinternal quantum efficiencyVSAvoidbrightness

Core Design Contradiction:

Use of energy by moving objectVSIllumination intensity

Solution Approach 1:

The patent adjusts molecular parameters including HOMO-LUMO energy gaps, triplet energy levels, and steric hindrance parameters to prevent exciton-polaron quenching at high brightness. The specific substitution patterns on the host molecules optimize these parameters to maintain efficiency across wide brightness ranges

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If blue phosphorescent devices are designed, then desired emission color is achieved, but color is non-saturated and device lifetime is short

Engineering Contradiction:

Improveemission colorVSAvoiddevice lifetime

Core Design Contradiction:

Ease of manufactureVSDuration of action of stationary object

Solution Approach 1:

The patent introduces specific local structural features - particular heteroaryl groups at specific positions on the host molecule - that locally enhance triplet energy and stabilize the blue-emitting state. This local modification achieves saturated blue color while preventing the rapid degradation that plagues blue phosphorescent devices

Inventive Principle:

Principle #3Local quality

4Ease of manufacture

If conventional host materials are used, then device fabrication is straightforward, but charge transport and exciton manipulation are insufficient

Engineering Contradiction:

Improvefabrication simplicityVSAvoidcharge transport efficiency

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent optimizes key parameters of host materials including molecular weight, glass transition temperature, and charge carrier mobility to achieve excellent charge transport while maintaining solution processability. The specific molecular structures balance these parameters for both performance and manufacturability

Inventive Principle:

Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The combination significantly improves device efficiency, extends lifetime, and reduces voltage, offering better performance and commercial prospects for organic electroluminescent devices.

Implementation Method 1

Organic electroluminescent device

Methodology Applied

Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentUS20220231232A1Organic electroluminescent device

Publication Date: 2022.07.21 BEIJING SUMMER SPROUT TECH CO LTD

AI summary

Provided is an organic electroluminescent device. The organic electroluminescent device comprises a first compound having a structure of Formula 1 and a second compound having a structure of Formula 2. Compared to the related art or a device comprising only the first compound or the second compound, a combination of the first compound and the second compound can significantly improve the overall performance of the organic electroluminescent device, such as improved device efficiency, an extended device lifetime and reduced device voltage. Further provided are a display assembly comprising the organic electroluminescent device and a compound composition comprising the first compound and the second compound.