OLED Electron Transport Layer Pyrimidine Compound Efficiency

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Solution Overview

Problem

Current organic light-emitting devices face challenges in achieving high efficiency, long lifespan, and reduced driving voltages, with existing materials not adequately addressing these requirements.

Innovation Solution

Incorporation of a novel cyclic compound in the electron transport layer, specifically represented by Formula 1, which enhances the performance of organic light-emitting devices by optimizing electron transport characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional electron transport materials are used in the electron transport layer, then the device structure is simple, but the device efficiency is low and lifespan is short

Engineering Contradiction:
Improvedevice efficiencyVSAvoidmaterial structure complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent modifies the electron transport material by changing molecular parameters - specifically introducing a pyrimidine ring core with specific substituent groups (R1-R6) at defined positions. This parameter change in molecular structure optimizes electron mobility and HOMO/LUMO energy levels, directly improving device efficiency and lifespan while maintaining reasonable structural complexity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite material design by combining a pyrimidine ring core with various aromatic substituent groups (such as phenyl, naphthyl, carbazolyl groups). This composite structure integrates the electron-transporting capability of the pyrimidine core with the stabilizing and tunable properties of aromatic substituents, achieving high efficiency and long lifespan

Inventive Principle:
Principle #40Composite materials

2Power

If conventional electron transport materials are used, then the material selection is simple, but the driving voltage remains high

Engineering Contradiction:
Improvedriving voltageVSAvoidmaterial selection flexibility
Core Design Contradiction:
PowerVSAdaptability or versatility

Solution Approach 1:

The patent systematically varies molecular parameters including the type of aromatic substituents (R1-R6), their positions on the pyrimidine ring, and the nature of linking groups to optimize the HOMO and LUMO energy levels. This parameter optimization enables lower driving voltages by improving electron injection efficiency from the cathode while maintaining adequate electron transport capability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The pyrimidine-based electron transport material exhibits multi-functionality by simultaneously providing electron transport, voltage reduction through optimized energy levels, and structural stability. The universal applicability of this molecular framework allows it to be used in various OLED configurations (phosphorescent, electrophosphorescent, fluorescent) with different emission colors

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Duration of action of stationary object

If existing phosphorescent hosts and dopants are used, then the emission characteristics are conventional, but the device lifespan is limited

Engineering Contradiction:
Improvedevice lifespanVSAvoidemission characteristics
Core Design Contradiction:
Duration of action of stationary objectVSIllumination intensity

Solution Approach 1:

The patent optimizes the electron transport layer material parameters to achieve better energy level matching with phosphorescent emitters, reducing energy loss and improving device stability. The modified electron transport materials exhibit enhanced thermal and morphological stability, which directly extends device operational lifespan while maintaining or improving emission characteristics

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 use of this novel compound improves the performance of organic light-emitting devices by enhancing efficiency, extending lifespan, and reducing driving voltages, thereby addressing the limitations of existing materials.

Implementation Method 1

Holes provided by the first electrode may move toward the emission layer through the hole transport region, and electrons provided by the second electrode may move toward the emission layer through the electron transport region. Carriers (such as holes and electrons) may recombine in the emission layer to produce excitons. These excitons may transition (e.g., radiatively decay) from an excited state to the ground state to thereby generate light.

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentEP3214153B1Organic light-emitting device
Publication Date: 2020.03.25 SAMSUNG DISPLAY CO LTD
  • EP3214153B1 patent drawingFigure 1
  • EP3214153B1 patent drawingFigure 2
  • EP3214153B1 patent drawingFigure 3

AI summary

Organic Light-Emitting Device An organic light-emitting device comprising: a first electrode; a second electrode facing the first electrode; and an organic layer between the first electrode and the second electrode and comprising an emission layer, wherein the organic layer comprises: i) a hole transport region between the first electrode and the emission layer, and comprising at least one selected from a hole injection layer, a hole transport layer, an emission auxiliary layer, and an electron blocking layer, and ii) an electron transport region between the emission layer and the second electrode and comprising an electron transport layer, in addition to at least one selected from a hole blocking layer, an electron control layer, a buffer layer, and an electron injection layer, wherein the electron transport region comprises a compound represented by Formula 1: