Polycyclic Compound TADF Dopant for OLED Emission Efficiency

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Solution Overview

Problem

Current organic electroluminescence devices face challenges in achieving high emission efficiency and long lifespan, as existing light-emitting materials do not efficiently utilize triplet excitons, leading to energy loss and reduced device performance.

Innovation Solution

Incorporation of a polycyclic compound with a specific structure, represented by Formula 1, as a dopant in the emission layer, which promotes intersystem crossing and enables thermally activated delayed fluorescence (TADF) without energy loss, enhancing emission efficiency and extending device lifespan.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional light-emitting materials are used in the emission layer, then the device structure is simple, but triplet excitons are not efficiently utilized leading to low emission efficiency

Engineering Contradiction:
Improveemission efficiencyVSAvoidenergy loss from triplet excitons
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The patent modifies the molecular structure parameters of the light-emitting material by introducing a specific polycyclic compound structure with Formula 1, which contains a condensed ring system with specific substituents. This structural parameter change enables efficient triplet exciton utilization through TADF mechanism, resolving the contradiction between emission efficiency and energy loss

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs a composite material system where the polycyclic compound (Formula 1) is used as a dopant in the emission layer, combining it with host materials to create a synergistic system. This composite approach allows the polycyclic compound to facilitate TADF while the host material provides structural support, achieving high emission efficiency without significant energy loss

Inventive Principle:
Principle #40Composite materials

2Duration of action of stationary object

If existing light-emitting materials are used, then the device has simpler material requirements, but the device lifespan is reduced due to energy loss

Engineering Contradiction:
Improvedevice lifespanVSAvoidenergy loss
Core Design Contradiction:
Duration of action of stationary objectVSLoss of energy

Solution Approach 1:

By changing the molecular parameters of the light-emitting material to the specific polycyclic structure (Formula 1), the patent reduces energy loss through efficient triplet exciton utilization. This parameter change directly extends device lifespan by minimizing energy degradation pathways that would otherwise accelerate material degradation

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent converts the previously harmful triplet excitons, which caused energy loss and reduced lifespan, into beneficial light-emitting states through the TADF mechanism enabled by the polycyclic compound structure. This transforms the harmful energy loss pathway into a useful light emission pathway, extending device lifespan

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 polycyclic compound significantly improves emission efficiency and extends the lifespan of organic electroluminescence devices by efficiently utilizing triplet excitons through TADF, achieving high emission efficiency and long device life.

Implementation Method 1

promotes intersystem crossing and enables thermally activated delayed fluorescence (TADF) without energy loss

Methodology Applied
Scientific EffectIntersystem crossing:

Implementation Method 2

enables thermally activated delayed fluorescence (TADF) without energy loss

Methodology Applied
Scientific EffectThermally activated delayed fluorescence:

Implementation Method 3

efficiently utilizing triplet excitons through TADF, achieving high emission efficiency

Methodology Applied
Scientific EffectTADF emission:

Data Source

PatentEP3508490B1Organic electroluminescence device and polycyclic compound for organic electroluminescence device
Publication Date: 2022.03.09 SAMSUNG DISPLAY CO LTD
  • EP3508490B1 patent drawingFigure 1~2
  • EP3508490B1 patent drawingFigure 3
  • EP3508490B1 patent drawing

AI summary

An organic electroluminescence device and a polycyclic compound used for the organic electroluminescence device are provided. The polycyclic compound according to an embodiment of the inventive concept is represented by Formula 1. In Formula 1, Y is B, P=O, or P=S, and X is SiR3R4, or GeR5R6. At least one of R1 or R2 is NAr2Ar3.