Transparent Electrode Thickness for LED Light Extraction
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Solution Overview
Problem
Current light emitting devices using Group III-V nitride semiconductors face challenges in optimizing the thickness of the transparent electrode layer to enhance light extraction efficiency and transmittance, which affects the overall performance of LEDs and LDs.
Innovation Solution
The solution involves adjusting the thickness of the transparent electrode layer, specifically within the range of 55 nm to 65 nm, to improve transmittance and reduce reflectivity, thereby enhancing light extraction efficiency and the overall performance of light emitting devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the thickness of the transparent electrode layer is increased, then the electrical conductivity is improved, but the light transmittance deteriorates
Solution Approach 1:
The patent applies parameter changes by precisely controlling the thickness of the transparent electrode layer within the range of 55 nm to 65 nm. This specific thickness parameter optimization allows the electrode to maintain sufficient electrical conductivity while minimizing light absorption and reflection, thereby maximizing light transmittance and extraction efficiency.
2Illumination intensity
If the thickness of the transparent electrode layer is decreased, then the light transmittance is improved, but the electrical conductivity deteriorates
Solution Approach 1:
The patent resolves this contradiction by establishing a specific thickness parameter range (55 nm to 65 nm) for the transparent electrode layer. Within this range, the electrode maintains adequate electrical conductivity for current injection while minimizing optical losses through reduced absorption and reflection, thus achieving both electrical and optical performance requirements.
3Ease of manufacture
If the thickness of the transparent electrode layer is not optimized, then the manufacturing process is simpler, but the light extraction efficiency deteriorates
Solution Approach 1:
The patent addresses this contradiction by defining a specific thickness parameter range (55 nm to 65 nm) for the transparent electrode layer. This parameter optimization ensures that standard manufacturing processes can produce electrodes with appropriate thickness, achieving high light extraction efficiency without requiring complex additional processing steps.
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 adjustment significantly improves light extraction efficiency and transmittance, leading to enhanced luminous intensity and color rendering index, while also improving the reliability of semiconductor light emitting devices and their packages.
Implementation Method 1
a transparent electrode layer 120 having a thickness of not more than 65 nm and covering substantially the entire upper surface of the second conductive type semiconductor layer 115
Implementation Method 2
adjusting the thickness of the transparent electrode layer to enhance light extraction efficiency and transmittance
Data Source
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AI summary
A light emitting device includes a light emitting structure including a first conductive type semiconductor layer, an active layer on the first conductive type semiconductor layer, and a second conductive type semiconductor layer on the active layer; and a transparent electrode layer formed at least one of on and under the light emitting structure, wherein the transparent electrode layer has a thickness in a range of 30 nm to 70 nm to obtain a transmittance equal to or greater than 70% with respect to a wavelength range of light of 420 nm to 510 nm.