Organic Electroluminescence Device with Recessed Micro-Cavity Light Extraction
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Solution Overview
Problem
Conventional organic electroluminescence devices face challenges in achieving both high light usage efficiency and color purity simultaneously, with existing solutions either improving light usage efficiency but not color purity, or vice versa, due to limitations in light extraction and microcavity effects.
Innovation Solution
The proposed organic electroluminescence device incorporates a base material with a recessed surface, a reflective layer, a filling layer with light transmissivity, and electrodes with both light transmissivity and reflectivity, along with a semi-transmissive/reflective film, to enhance light extraction and microcavity effects, allowing for superior light usage efficiency and color purity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a light-reflecting layer with a recess is used to improve light usage efficiency, then light extraction efficiency is improved, but color purity cannot be increased
Solution Approach 1:
The patent combines the light extraction function (via recess structure and reflective layer) with the color purity enhancement function (via microcavity effect and dielectric stacked layer) into a single integrated device structure. The recess is filled with alternating high-refractive-index and low-refractive-index dielectric layers that simultaneously serve as both light extraction enhancement structures and microcavity resonance structures, allowing both light usage efficiency and color purity to be improved together
2Manufacturing precision
If a microcavity structure with alternately stacked dielectric films is used to improve color purity, then color purity is improved, but light extraction efficiency for all light is difficult to improve
Solution Approach 1:
The patent applies local quality by creating recess structures with specific geometries (including inclined surfaces) in the dielectric stacked layer. These localized structural variations enable different regions to perform different functions: some regions optimize for microcavity resonance (color purity) while others optimize for light extraction, allowing both objectives to be achieved simultaneously in different parts of the same structure
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
This configuration enables the organic electroluminescence device to achieve improved light extraction efficiency and color purity, allowing for adjustable light extraction and color purity, surpassing the limitations of conventional devices.
Implementation Method 1
a reflective layer that is provided at least along a surface of the recess
Implementation Method 2
a filling layer that is filled into an inside of the recess via the reflective layer, the filling layer having light transmissivity
Implementation Method 3
a first electrode that is provided at least on a layer above the filling layer, the first electrode having light transmissivity and light reflectivity
Data Source
AI summary
An organic electroluminescence device according to one aspect of the present invention includes: a base material in which a recess is provided at an upper surface of the base material; a reflective layer that is provided at least along a surface of the recess; a filling layer that is filled into an inside of the recess via the reflective layer, the filling layer having light transmissivity; a first electrode that is provided at least on a layer above the filling layer, the first electrode having light transmissivity and light reflectivity; an organic layer that is provided on a layer above the first electrode, the organic layer including at least a light-emitting layer; and a second electrode that is provided on a layer above the organic layer, the second electrode having light transmissivity and light reflectivity. A part of the reflective layer contacts a part of the first electrode.