Electroluminescent Display Electrode Insulation for Stable Luminance

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Solution Overview

Problem

Existing organic electroluminescence display devices experience fluctuations in light emission luminance due to carrier leakage and trapping issues.

Innovation Solution

A display device design featuring a first electrode layer with two-dimensionally arranged electrodes, a second electrode layer, an electroluminescence layer, and an insulating layer with localized portions and openings that form a potential barrier between the electroluminescence layer and localized portions to trap and retain carriers, reducing luminance fluctuations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an insulating layer is provided between adjacent electrodes, then electrical insulation between electrodes is improved, but carrier leakage and trapping occurs at the interface between the insulating layer and electroluminescence layer, causing luminance fluctuation

Engineering Contradiction:

Improveelectrical insulation between electrodesVSAvoidluminance stability

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The insulating layer is designed with localized portions having different properties: regions directly beneath electrodes have higher insulation density to prevent carrier trapping, while inter-electrode regions provide electrical isolation. This spatial variation in insulating quality resolves the contradiction by optimizing both insulation performance and luminance stability in different locations.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

A buffer layer or interface treatment layer is introduced between the insulating layer and the electroluminescence layer to mediate the interaction. This intermediary layer prevents direct contact between carriers and the insulating layer interface, eliminating carrier trapping while maintaining electrical insulation functionality.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the insulating layer is made continuous to ensure complete electrical isolation, then electrical insulation is improved, but carrier trapping at the interface increases, worsening luminance stability

Engineering Contradiction:

Improveelectrical insulation between electrodesVSAvoidluminance stability

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The insulating layer transitions from a uniform continuous structure to a non-uniform structure with varying local properties. Regions beneath electrodes are optimized for carrier repulsion, while inter-electrode regions maintain insulation. This local differentiation resolves the contradiction between continuous insulation and reduced carrier trapping.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The insulating layer is functionally segmented into different regions with distinct roles: electrode-facing regions for carrier management and inter-electrode regions for insulation. This segmentation allows each region to optimize its function, resolving the contradiction between complete isolation and minimal carrier trapping.

Inventive Principle:

Principle #1Segmentation

3Stability of the object's composition

If openings are added to the insulating layer to reduce carrier trapping, then luminance stability is improved, but electrical insulation between adjacent electrodes may be compromised

Engineering Contradiction:

Improveluminance stabilityVSAvoidelectrical insulation between electrodes

Core Design Contradiction:

Stability of the object's compositionVSReliability

Solution Approach 1:

The insulating layer with openings exhibits local quality differentiation: opened regions allow carrier evacuation to prevent trapping and improve luminance stability, while the surrounding insulating material maintains electrical insulation between electrodes. This spatially selective structure resolves the contradiction between luminance stability and electrical insulation.

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 design effectively suppresses reversible luminance fluctuations by preventing carrier detrapping, maintaining consistent light emission.

Implementation Method 1

the insulating layer forms a potential barrier between the electroluminescence layer and a localized portion

Methodology Applied

Scientific EffectPotential barrier: Electric Field

Data Source

PatentUS12557480B2Display device and electronic device

Publication Date: 2026.02.17 SONY GROUP CORP

AI summary

Provided is a display device capable of suppressing fluctuation in light emission luminance.A display device includes: a first electrode layer having a plurality of electrodes arranged two-dimensionally; a second electrode layer provided to face the first electrode layer; an electroluminescence layer provided between the first electrode layer and the second electrode layer; and an insulating layer provided between adjacent electrodes. The insulating layer has a plurality of openings, and each of the plurality of openings is provided corresponding to each of the electrodes. The insulating layer includes a plurality of localized portions, and each of the plurality of localized portions is localized around each of the openings. The insulating layer forms a potential barrier between the electroluminescence layer and the localized portion.