Light Emitting Unit Protecting Layer for Higher Light Extraction
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Solution Overview
Problem
Current light emitting diodes face challenges in chip reliability and light extraction efficiency, necessitating improved designs for enhanced performance in compact display devices.
Innovation Solution
A light emitting unit comprising a semiconductor layer with a protecting layer that has varying oxygen and nitrogen atomic percentages, which reduces refractive index differences and promotes light extraction, while also improving chip reliability through a rough surface topography and specific material compositions like GaOxNy for the protecting layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional protecting layer with uniform composition is used, then the manufacturing process is simple, but light extraction efficiency is poor due to total internal reflection at the interface
Solution Approach 1:
The protecting layer is designed with non-uniform oxygen and nitrogen concentrations, creating a gradient structure where the composition varies through the thickness of the layer. This gradient structure reduces total internal reflection by gradually changing the refractive index, thereby improving light extraction efficiency without significantly complicating the manufacturing process.
Solution Approach 2:
The patent changes the chemical composition parameters (oxygen and nitrogen atomic percentages) of the protecting layer to create a gradient structure. By controlling the variation of these parameters through the layer thickness, the refractive index is optimized to reduce total internal reflection and enhance light extraction efficiency.
2Ease of manufacture
If the protecting layer has a smooth surface, then the manufacturing process is easier, but the area capable of emitting light is reduced
Solution Approach 1:
The protecting layer is designed with a rough surface topography featuring convex and concave portions instead of a smooth flat surface. This curved and irregular surface structure increases the effective light emission area and reduces total internal reflection, thereby enhancing light extraction efficiency while maintaining manufacturing feasibility through standard deposition techniques.
3Stability of the object's composition
If the protecting layer has high oxygen content, then the material stability is improved, but the refractive index mismatch increases causing more total reflection
Solution Approach 1:
The protecting layer exhibits spatial variation in oxygen content, with higher oxygen concentration near the semiconductor layer interface and lower oxygen concentration toward the outer surface. This local quality variation creates a refractive index gradient that reduces total internal reflection while maintaining material stability through controlled compositional distribution.
Solution Approach 2:
The protecting layer is designed as a composite structure containing both oxygen and nitrogen elements in varying proportions. This composite material approach allows optimization of both material stability (through oxygen content) and light extraction efficiency (through nitrogen content and gradient structure), achieving a balance between conflicting requirements.
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 enhances light extraction efficiency and chip reliability by reducing total reflections and increasing the area capable of emitting light, thereby improving the overall performance of light emitting diodes in display devices.
Implementation Method 1
the protecting layer has a region in which oxygen atomic percentages decrease toward the semiconductor layer... the protecting layer has a region in which nitrogen atomic percentages increase toward the semiconductor layer
Implementation Method 2
enhances light extraction efficiency by reducing total reflections
Data Source
AI summary
An electronic device includes: a semiconductor layer; and a protecting layer disposed on the semiconductor layer, wherein the protecting layer has a region in which oxygen atomic percentages decrease toward the semiconductor layer.