OLED Ink Composition for Stable Large-Area Thin Films

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Solution Overview

Problem

Existing organic light-emitting device manufacturing methods face challenges such as material loss and difficulty in producing large-area devices due to the deposition process, necessitating the development of a solution-based process.

Innovation Solution

An ink composition comprising a specific compound, first and second solvents, which forms a stable thin film through curing, enabling a solution process that allows for large-area device production with improved efficiency and flatness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a deposition process is used to manufacture organic light-emitting devices, then device performance can be achieved, but material loss occurs frequently and it is difficult to manufacture large-area devices

Engineering Contradiction:
Improvedevice performanceVSAvoidmaterial loss
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent employs a solution process using ink composition that can be applied through printing or coating methods, replacing the traditional vacuum deposition process. This allows the organic material to be deposited in solution form and then cured to form functional layers, eliminating the material loss associated with deposition processes while enabling large-area manufacturing.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The patent changes the physical state of the organic material from solid (deposition) to solution (ink composition), and introduces a curing step to transform the solution into a functional film. This parameter change enables material-efficient processing and scalability to large areas while maintaining device performance.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If a deposition process is used to manufacture organic light-emitting devices, then device performance can be achieved, but it is difficult to manufacture large-area devices

Engineering Contradiction:
Improvedevice performanceVSAvoiddevice area
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The solution-based ink composition can be applied using printing or coating techniques that are inherently suitable for large-area processing. The liquid ink can be uniformly distributed over large surfaces and then cured to form the required organic layers, enabling manufacturing of large-area devices that are difficult to achieve with deposition processes.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

By changing from solid deposition to liquid solution processing with subsequent curing, the patent enables scalable manufacturing processes that can cover large areas. The solution process allows for uniform material distribution and curing across large surfaces, overcoming the area limitations of deposition methods.

Inventive Principle:
Principle #35Parameter changes

3Area of stationary object

If a solution process is used to form organic material layers, then large-area manufacturing is enabled, but the thin film stability may be compromised

Engineering Contradiction:
Improvedevice areaVSAvoidthin film stability
Core Design Contradiction:
Area of stationary objectVSStability of the object's composition

Solution Approach 1:

The patent utilizes a phase transition from liquid solution to solid film through a curing step. The ink composition is applied in liquid form to enable solution processing and large-area coverage, then cured to transform into a stable solid thin film that maintains compositional stability and functional performance.

Inventive Principle:
Principle #36Phase transitions

Solution Approach 2:

The ink composition comprises multiple components including organic compounds, solvents, and potentially additives that work together to form a stable cured film. This composite approach ensures that the solution process produces thin films with enhanced stability while maintaining the benefits of solution processing for large-area manufacturing.

Inventive Principle:
Principle #40Composite materials

4Area of moving object

If pixel size is reduced to increase resolution, then device density improves, but maintaining film stability and performance becomes difficult

Engineering Contradiction:
Improvepixel sizeVSAvoidfilm stability
Core Design Contradiction:
Area of moving objectVSStability of the object's composition

Solution Approach 1:

The patent uses solution processing with ink composition that can be precisely controlled and uniformly applied even at small pixel dimensions. The curing step ensures that the thin films maintain stability and performance characteristics even when pixel sizes are reduced to increase device resolution.

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 ink composition facilitates the formation of a stable, flat thin film with low driving voltage and enhanced service life, suitable for organic light-emitting devices, even in small pixel sizes.

Implementation Method 1

forming a stable thin film through curing

Methodology Applied
Scientific EffectCuring: Photopolymerisation

Implementation Method 2

An organic light emission phenomenon is one of the examples of converting an electric current into visible rays through an internal process of a specific organic molecule

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentEP4484507B1Ink composition, organic material layer comprising same, and organic light-emitting device comprising same
Publication Date: 2026.04.01 LG CHEM LTD
  • EP4484507B1 patent drawingFigure 1~2
  • EP4484507B1 patent drawingFigure 3~4(b)
  • EP4484507B1 patent drawingFigure 5~6

AI summary

The present specification relates to an ink composition, an organic material layer including the same and an organic light emitting device including the same.