OLED Hole Transport Region Low-Temperature Curing

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Solution Overview

Problem

Current organic light-emitting devices face challenges in achieving high efficiency and long lifespan due to limitations in the materials and structures used in their manufacturing processes.

Innovation Solution

A light-emitting device with an inverted structure, featuring a substrate, cathode, electron transport region, emission layer, and hole transport region, where the hole transport region includes specific compounds represented by Formulas 1, 2, and 5, which facilitate low-temperature thermal or photocuring, minimizing thermal decomposition and enhancing efficiency and lifespan.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional materials and structures are used in organic light-emitting devices, then manufacturing is simpler, but efficiency and lifespan are limited

Engineering Contradiction:

ImprovelifespanVSAvoidstructure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies an inverted device structure where the hole transport region is positioned adjacent to the emission layer instead of the conventional electron transport region placement. This inversion enables the use of specific compounds (Formulas 1, 2, and 5) in the hole transport region that facilitate low-temperature curing, thereby extending device lifespan without significantly increasing structural complexity

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent changes the curing temperature parameter by using compounds that enable low-temperature thermal or photocuring. This parameter change prevents thermal decomposition of organic materials, thereby improving device lifespan and efficiency without requiring complex manufacturing processes

Inventive Principle:

Principle #35Parameter changes

2Productivity

If conventional materials are used in the hole transport region, then material selection is easier, but thermal decomposition occurs and efficiency decreases

Engineering Contradiction:

Improvemanufacturing efficiencyVSAvoidthermal decomposition

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the curing temperature parameter from high temperature to low temperature by selecting specific compounds (Formula 1: carbazole derivative, Formula 2: triphenylamine derivative, Formula 5: heterocyclic compound) for the hole transport region. This parameter change enables curing below the thermal decomposition point of organic materials, eliminating thermal decomposition while maintaining efficient manufacturing

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent substitutes thermal curing at high temperature with low-temperature thermal or photocuring using specific chemical compounds. This substitution replaces a harmful high-temperature process with a gentler low-temperature process that achieves the same curing function without causing thermal decomposition

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If high efficiency is achieved through material optimization, then lifespan improves, but driving voltage increases

Engineering Contradiction:

ImprovelifespanVSAvoiddriving voltage

Core Design Contradiction:

ReliabilityVSPower

Solution Approach 1:

The patent applies local quality by optimizing only the hole transport region adjacent to the emission layer with specific compounds (Formulas 1, 2, and 5). This localized optimization improves efficiency and lifespan at the critical interface without requiring global material changes that would increase driving voltage, thereby maintaining power levels while improving reliability

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

The proposed structure and material composition result in improved efficiency characteristics and extended lifespan of the light-emitting device, maintaining performance without significant increases in driving voltage.

Implementation Method 1

the hole transport region includes specific compounds represented by Formulas 1, 2, and 5, which facilitate low-temperature thermal or photocuring

Methodology Applied

Scientific EffectPhotocuring: Photopolymerisation

Data Source

PatentUS20230135917A1Light-emitting device and method of manufacturing the same

Publication Date: 2023.05.04 SAMSUNG DISPLAY CO LTD

AI summary

A light-emitting device includes: a substrate; a cathode on the substrate; an anode on the cathode; and an organic layer arranged between the cathode and the anode and including an emission layer. The organic layer includes: an electron transport region between the emission layer and the cathode; and a hole transport region between the emission layer and the anode, wherein the hole transport region includes a first compound including a first repeating unit represented by Formula 1, a second compound represented by Formula 2, a fifth compound represented by Formula 5, or any combination thereof, wherein Formulas 1, 2, and 5 are respectively the same as described herein.