OLED Resonance Structure With Low-Index Layer for Light Extraction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing organic light emitting display devices suffer from low light efficiency due to significant light dissipation when light generated from the emission layer is discharged to the outside environment, primarily through the encapsulation layer.
Innovation Solution
The introduction of a light extraction reduction preventing layer with a low refractive index, disposed between the display unit and the encapsulation layer, helps establish a resonance condition, thereby minimizing light dissipation and enhancing light extraction efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an encapsulation layer with inorganic and organic layers is used to protect the display unit, then protection against oxygen and moisture is improved, but light dissipation increases and light extraction efficiency deteriorates
Solution Approach 1:
A light extraction reduction preventing layer with refractive index 1.1-1.5 is introduced as an intermediary between the display unit and the encapsulation layer. This intermediate layer creates a resonance structure that reduces light dissipation while allowing the encapsulation layer to maintain its protective function. The intermediary layer's specific refractive index range is optimized to minimize light loss without compromising the barrier properties against oxygen and moisture.
2Loss of energy
If a light extraction reduction preventing layer with low refractive index is added between the display unit and encapsulation layer, then light extraction efficiency is improved, but device structure becomes more complex
Solution Approach 1:
The invention optimizes the refractive index parameter of the light extraction reduction preventing layer to fall within 1.1-1.5, which is lower than both the display unit and encapsulation layer. This specific parameter range creates the necessary resonance condition to reduce light dissipation. The layer thickness is also controlled at 20-200 nm to achieve optimal performance while minimizing added structural complexity.
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 improves the light emission efficiency of the organic light emitting display device by reducing light dissipation and optimizing the resonance condition during the light extraction process.
Implementation Method 1
properly controlling a refractive index difference between a display unit and an encapsulation layer to properly establish a resonance condition
Implementation Method 2
controlling a refractive index difference between a display unit and an encapsulation layer
Data Source
AI summary
An organic light emitting display device including a light extraction reduction preventing layer disposed between a display unit disposed on a substrate and an encapsulation layer for protecting the display unit, which improves light emission efficiency by reducing an amount of light dissipating while light generated from an emission layer of the display unit is extracted to the outside.