Organic Light-Emitting Device Stacked Layers Triplet Energy Transfer

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Solution Overview

Problem

Existing organic light-emitting devices face challenges in achieving effective carrier transfer and triplet energy transfer between stacked light-emitting layers, which affects their durability.

Innovation Solution

The organic light-emitting device incorporates a stacked light-emitting layer configuration with a first light-emitting layer containing a first organic compound, a first metal complex, and a second metal complex, and a second light-emitting layer containing a second organic compound and a third metal complex, where specific triplet energy relationships and concentrations promote efficient energy transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If stacked light-emitting layers are used to achieve full-color display, then color variety is improved, but carrier transfer and triplet energy transfer between layers become difficult, reducing durability

Engineering Contradiction:

Improvecolor varietyVSAvoiddriving durability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent introduces a specific organic compound (formula 1) as an intermediary material in the light-emitting layer to facilitate triplet energy transfer between stacked phosphorescent layers. This intermediary compound has carefully designed energy levels that enable efficient energy transfer from the first phosphorescent layer to the second phosphorescent layer, solving the transfer difficulty while maintaining full-color capability through multiple stacked layers

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent systematically adjusts key parameters including the energy levels (HOMO/LUMO), triplet energy (T1), and molecular structure of the organic compound in formula (1) to optimize both energy transfer efficiency and carrier transfer. By changing these parameters, the invention achieves improved driving durability while maintaining the stacked layer configuration for full-color display

Inventive Principle:

Principle #35Parameter changes

2Use of energy by moving object

If multiple phosphorescent materials are stacked to improve luminous efficiency, then energy utilization is improved, but the complexity of energy level matching increases, making it difficult to achieve effective triplet energy transfer

Engineering Contradiction:

Improveluminous efficiencyVSAvoidenergy level matching complexity

Core Design Contradiction:

Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent assigns different functional roles to different components: the first phosphorescent material (formula 2) provides primary emission, the second phosphorescent material (formula 3) provides secondary emission for full-color, and the organic compound (formula 1) specifically facilitates energy transfer. This local specialization of functions simplifies the overall energy level matching requirement while maintaining high luminous efficiency through multiple phosphorescent materials

Inventive Principle:

Principle #3Local quality

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

This configuration enhances carrier transfer and triplet energy transfer, leading to improved driving durability and luminous efficiency of the organic light-emitting device.

Implementation Method 1

carrier transfer and triplet energy transfer between stacked light-emitting layers

Methodology Applied

Scientific EffectTriplet energy transfer:

Implementation Method 2

T1D2≥T1D1 and T1D3≥T1D2 where T1D1 is the triplet energy of the first metal complex, T1D2 is the triplet energy of the second metal complex, and T1D3 is the triplet energy of the third metal complex

Methodology Applied

Scientific EffectEnergy transfer:

Implementation Method 3

The organic light-emitting device (hereinafter, also referred to as an 'organic electroluminescent device' or an 'organic EL device') is a device that emits light by energizing an anode, a cathode, and organic electroluminescent (EL) layers including a light-emitting layer

Methodology Applied

Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentUS20250185455A1Organic light-emitting device

Publication Date: 2025.06.05 CANON KK

AI summary

An organic light-emitting device having improved carrier transfer and triplet energy transfer between stacked light-emitting layers and having improved driving durability. The light-emitting layers include a first light-emitting layer and a second light-emitting layer. The first light-emitting layer contains a first organic compound, a first metal complex, and a second metal complex. The second light-emitting layer contains a second organic compound and a third metal complex and is free of the first metal complex. Relationships represented by the following formulae [a] to [c] hold:T1D2≥T1D1 [a]T1D3≥T1D2 [b]T⁢1⁢D⁢2-T⁢1⁢D⁢1>T⁢1⁢D⁢3-T⁢1⁢D⁢2[c]where T1D1 is the triplet energy of the first metal complex, T1D2 is the triplet energy of the second metal complex, and T1D3 is the triplet energy of the third metal complex.