LED Chip Current Blocking Layer Light Extraction
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Solution Overview
Problem
Current light-emitting diode (LED) chip designs suffer from suboptimal luminous efficiency due to inefficient light output from both the top and side surfaces, leading to wasted light and reduced overall lighting effectiveness.
Innovation Solution
The LED chip incorporates a current blocking layer with alternately stacked high and low refractive index layers, a transparent conductive layer, and a specific electrode width ratio to enhance light reflectivity and transmittance, optimizing light extraction efficiency by adjusting the thickness and arrangement of these layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional LED chip structure is used, then the manufacturing process is simple, but the luminous efficiency is suboptimal due to inefficient light output
Solution Approach 1:
The patent applies composite materials by stacking multiple layers with different refractive indices (high refractive index layers and low refractive index layers) to form a current blocking layer. This composite structure enhances light extraction efficiency through optical interference effects, resolving the contradiction between manufacturing simplicity and luminous efficiency by adding a multi-layer composite structure that can be integrated into existing LED fabrication processes.
Solution Approach 2:
The patent changes optical parameters by controlling the thickness, refractive index, and arrangement of alternating high and low refractive index layers. By optimizing these parameters, the structure achieves enhanced light output through constructive interference and reduced internal reflection, thereby improving luminous efficiency while maintaining compatibility with standard manufacturing techniques.
2Reliability
If the current blocking layer width is increased to block more current, then current blocking effectiveness improves, but the light output area is reduced
Solution Approach 1:
The patent applies local quality by creating a current blocking layer with spatially varying optical properties through alternating high and low refractive index layers. The structure provides different functions in different regions: effective current blocking in the electrode area while maintaining light extraction efficiency in the active region, thus resolving the contradiction between current blocking effectiveness and light output area.
Solution Approach 2:
The patent resolves the width contradiction by transitioning from a single-dimensional width parameter to a multi-dimensional structure with alternating layers of different refractive indices. This vertical layering approach allows the current blocking function to be achieved through optical interference in the vertical dimension rather than relying solely on horizontal width, preserving light output area while maintaining blocking effectiveness.
3Productivity
If alternately stacked high and low refractive index layers are added to enhance light extraction, then luminous efficiency improves, but device complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the current blocking layer into multiple alternating segments of high and low refractive index materials. This segmented structure creates optical interference effects that enhance light extraction efficiency. The segmentation approach resolves the contradiction by breaking down a complex optical function into manageable repeating units that can be fabricated using standard thin-film deposition techniques.
Solution Approach 2:
The patent uses composite materials consisting of alternating high and low refractive index layers to achieve enhanced light extraction. This composite structure leverages optical interference principles to improve luminous efficiency while using materials and fabrication methods compatible with existing LED manufacturing processes, thus managing device 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 significantly enhances the luminous efficiency of the LED chip by redirecting and reflecting light to improve output from both the top and side surfaces, resulting in improved light output power and reliability.
Implementation Method 1
The current blocking layer includes a plurality of high refractive index layers and a plurality of low refractive index layers, and the high refractive index layers and the low refractive index layers are alternately stacked
Implementation Method 2
The current blocking layer includes a plurality of high refractive index layers and a plurality of low refractive index layers, and the high refractive index layers and the low refractive index layers are alternately stacked
Data Source
AI summary
A light emitting diode (LED) chip including a first type semiconductor layer, an light-emitting layer, a second type semiconductor layer, a current blocking layer, a transparent conductive layer and an electrode is provided. The light-emitting layer is disposed on the first type semiconductor layer. The second type semiconductor layer is disposed on the light-emitting layer. The current blocking layer is disposed on the second type semiconductor layer. The transparent conductive layer is disposed on the second type semiconductor layer and covered the current blocking layer. The electrode is disposed on the transparent conductive layer corresponding to the current blocking layer. The current blocking layer and the electrode respectively have a first width and a second width in a cross section view, and the first width of the current blocking layer is larger than the second width of the electrode.