Organic Emitting Layer Energy-Level Tuning for OLED Lifespan

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Solution Overview

Problem

Existing organic electric elements used in display devices face challenges in achieving high efficiency and long lifetime, particularly in portable devices where battery power is limited, and there is a need to control the energy levels of the organic layer to improve efficiency, lifespan, and driving voltage.

Innovation Solution

The organic electric element comprises a first electrode, a second electrode, and an organic layer with specific molecular orbital energy level configurations, including a first layer with a first compound and a second compound, and a charge generating layer with specific molecular orbital energy levels, satisfying predetermined energy level formulas to enhance efficiency and lifespan.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional organic layers are used in organic electric elements, then the device can be manufactured with standard materials, but the luminous efficiency and lifespan are insufficient for portable display applications

Engineering Contradiction:
Improveluminous efficiencyVSAvoidlifespan
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies parameter changes by precisely controlling the energy levels (HOMO and LUMO) of the organic layer materials to satisfy specific mathematical relationships. The first compound has LUMO level L1, the second compound has HOMO level H2, and the third compound has HOMO level H3, where 0.32 eV ≤ L1-H2 ≤ 0.8 eV and 0.80 eV ≤ L1-H3 ≤ 1.4 eV. This energy level optimization improves both electron-hole recombination efficiency (luminous efficiency) and device stability (lifespan) simultaneously.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite materials by combining three different organic compounds in the organic layer: a first compound (formula 1 or 2 with cyano group), a second compound (formula 7-12), and a third compound (formula 13). This composite structure allows each material to contribute specific properties - the first compound provides electron transport with appropriate LUMO level, the second compound provides hole transport with appropriate HOMO level, and the third compound enhances overall device performance, achieving both high efficiency and long lifespan.

Inventive Principle:
Principle #40Composite materials

2Reliability

If the energy levels of the organic layer are optimized to improve efficiency and lifespan, then device performance increases, but the manufacturing complexity and material selection difficulty increase

Engineering Contradiction:
ImprovelifespanVSAvoidmaterial selection complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent establishes clear parameter ranges for energy levels (0.32 eV ≤ L1-H2 ≤ 0.8 eV and 0.80 eV ≤ L1-H3 ≤ 1.4 eV) that guide material selection. By providing specific mathematical relationships and numerical ranges, the patent transforms the complex material selection process into a systematic approach where manufacturers can select materials that meet the specified energy level criteria, reducing uncertainty while achieving optimized performance.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies local quality by specifying particular structural features for each compound: the first compound must contain a cyano group in formulas 1 or 2, the second compound must follow formulas 7-12, and the third compound must follow formula 13. These localized structural requirements focus the material selection on specific chemical features rather than requiring comprehensive optimization of all material properties, simplifying the manufacturing process.

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 solution provides an organic electric element with improved luminous efficiency and extended lifespan by optimizing the molecular orbital energy levels within the organic layer, resulting in a display panel and device with enhanced performance.

Implementation Method 1

In general, an organic light emitting phenomenon refers to the phenomenon of converting electrical energy into light energy by means of an organic material.

Methodology Applied
Scientific EffectOrganic light emitting phenomenon: Electroluminescence

Data Source

PatentEP4216697B1Organic electric element, display panel comprising the same and display device comprising the same
Publication Date: 2025.12.17 LG DISPLAY CO LTD
  • EP4216697B1 patent drawingFigure 1
  • EP4216697B1 patent drawingFigure 2
  • EP4216697B1 patent drawingFigure 3~4

AI summary

An organic electric element, a display panel and a display device including the organic electric element are provided. The organic electric element includes a first electrode; a second electrode; and an organic layer positioned between the first electrode and the second electrode. The organic layer includes a first layer having a first compound and a second compound, and a emitting layer having a third compound. A specific general formula related to energy levels of the component compounds is satisfied so that they may have excellent efficiency or lifespan.