DBR Light-Emitting Structure for Exciton Extinction Control

Solution Overview

Problem

Existing light-emitting devices have inherent extinction times for excitons that cannot be controlled, limiting driving stability and efficiency.

Innovation Solution

Incorporation of a distributed Bragg reflector (DBR) layer with alternating layers of different refractive indices to adjust extinction times and enhance light efficiency and color purity, utilizing a Purcell effect to shorten exciton extinction times.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional light-emitting devices are used without DBR layer, then the structure is simpler, but the extinction time of excitons cannot be controlled and driving stability is limited

Engineering Contradiction:

Improvedriving stabilityVSAvoidstructure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The interlayer is segmented into multiple functional sub-layers: hole transport region, emission layer, and electron transport region. This segmentation allows independent optimization of each region's properties, enabling control over exciton behavior and extinction time while maintaining overall device functionality

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A distributed Bragg reflector (DBR) layer is introduced as an intermediary component between the emission layer and electrodes. The DBR layer mediates light emission by providing resonance enhancement and controlling extinction time through its periodic structure, thereby improving driving stability without requiring changes to the luminescent material itself

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If luminescent material is used to control extinction time, then extinction time can be adjusted, but the control range and precision are limited

Engineering Contradiction:

Improveextinction time controlVSAvoidextinction time adjustment range

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

Instead of changing the luminescent material properties, the invention changes physical parameters of the DBR layer structure. By adjusting the thickness, refractive index, and stacking configuration of the DBR layers, the extinction time can be precisely controlled across a wide range without being constrained by material-specific limitations

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The DBR layer introduces local optical quality variations through its periodic high-refractive-index and low-refractive-index layer structure. This local structural quality enables selective resonance enhancement at specific wavelengths and control over exciton extinction dynamics, providing versatile adjustment capability

Inventive Principle:

Principle #3Local quality

3Use of energy by moving object

If DBR layer with alternating refractive indices is introduced, then light efficiency and color purity are enhanced, but the device structure becomes more complex

Engineering Contradiction:

Improvelight efficiencyVSAvoidinterlayer structure complexity

Core Design Contradiction:

Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The DBR layer is merged with the electron transport region, combining optical resonance functionality with charge transport functionality in a single integrated structure. This merging reduces the need for separate optical and electrical functional layers, thereby improving light efficiency while limiting the increase in overall structural complexity

Inventive Principle:

Principle #5Merging (Combining)

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

Improves driving stability and lifespan of light-emitting devices by controlling extinction times and enhancing light efficiency through the DBR layer's resonance effect.

Implementation Method 1

Incorporation of a distributed Bragg reflector (DBR) layer with alternating layers of different refractive indices to adjust extinction times and enhance light efficiency and color purity, utilizing a Purcell effect to shorten exciton extinction times.

Methodology Applied

Scientific EffectPurcell effect:

Implementation Method 2

Incorporation of a distributed Bragg reflector (DBR) layer with alternating layers of different refractive indices to adjust extinction times and enhance light efficiency and color purity, utilizing a Purcell effect to shorten exciton extinction times.

Methodology Applied

Scientific EffectResonance: Resonance

Data Source

PatentUS12538700B2Light-emitting device and electronic apparatus comprising light-emitting device

Publication Date: 2026.01.27 SAMSUNG DISPLAY CO LTD

AI summary

A light-emitting device includes a first electrode, a second electrode facing the first electrode, and an interlayer disposed between the first electrode and the second electrode. The interlayer includes an emission layer, and a distributed Bragg reflector (DBR) layer in which a first layer and a second layer are alternately stacked. A refractive index of the first layer is different from a refractive index of the second layer.