LED Cladding Layer Structure for Low-Absorption Waveguiding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing laser diodes with thick transparent electrically conducting oxide layers face efficiency challenges due to high absorption coefficients, affecting their ageing stability and performance.
Innovation Solution
A light-emitting diode with a semiconductor layer sequence that includes a thin, transparent, and electrically conducting cladding layer structure, which reduces absorption and enhances current distribution, allowing for improved waveguiding and mode control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a thick transparent electrically conducting oxide layer is used, then ageing stability is improved, but absorption losses increase and efficiency decreases
Solution Approach 1:
The patent divides the cladding layer structure into multiple functional layers: a first cladding layer made of transparent electrically conducting oxide material for current distribution, and a second cladding layer made of semiconductor material for optical waveguiding. This segmentation allows each layer to perform its specific function optimally without the negative effects of a thick TCO layer, resolving the contradiction between ageing stability and absorption losses.
Solution Approach 2:
The patent introduces a second cladding layer made of semiconductor material as an intermediary between the first cladding layer (TCO) and the active layer. This intermediary layer provides the necessary optical waveguiding function that was previously requiring a thick TCO layer, thereby reducing absorption losses while maintaining ageing stability through the TCO layer's electrical properties.
2Ease of operation
If a thick transparent electrically conducting oxide layer is used, then current distribution is improved, but optical absorption increases
Solution Approach 1:
The patent segments the cladding structure into a first cladding layer (TCO) responsible for current distribution and a second cladding layer (semiconductor material) responsible for optical waveguiding. This allows the TCO layer to be thin enough to reduce optical absorption while still providing adequate current distribution through its electrically conducting properties.
3Loss of energy
If the cladding layer is made thinner, then absorption losses are reduced, but current distribution capability deteriorates
Solution Approach 1:
The patent creates a segmented cladding structure where the first cladding layer (TCO) maintains current distribution capability even at reduced thickness, while the second cladding layer (semiconductor material) provides the optical waveguiding function. This segmentation resolves the contradiction by distributing different functions to different layers.
Solution Approach 2:
The patent employs a composite cladding layer structure combining TCO material and semiconductor material, each contributing different properties. The TCO provides electrical conductivity for current distribution, while the semiconductor material provides optical waveguiding, creating a composite structure that overcomes the limitations of using a single material.
4Stability of the object's composition
If a thick cladding layer is used, then waveguiding is improved, but internal losses increase
Solution Approach 1:
The patent segments the waveguiding function from the electrical conducting function by creating a second cladding layer made of semiconductor material with appropriate refractive index for waveguiding, while the first cladding layer (TCO) provides current distribution. This allows thin-layer waveguiding with reduced internal losses from TCO absorption.
Solution Approach 2:
The second cladding layer acts as an intermediary that provides optical waveguiding through its semiconductor material properties and refractive index contrast, eliminating the need for a thick TCO layer and thereby reducing internal absorption losses while maintaining waveguiding stability.
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 proposed solution enhances the efficiency and service life of the light-emitting diode by reducing internal losses, increasing the slope of optical power to electrical current, and stabilizing the wavelength and spectral width.
Implementation Method 1
an active layer (3), which is configured and intended to generate light (8) in an active region (5) during operation
Implementation Method 2
transparent electrically conducting oxides have a large absorption coefficient, which can affect efficiency
Data Source
AI summary
A light-emitting diode is specified which includes a semiconductor layer sequence grown in a vertical direction and having an active layer, which is configured and provided to generate light in an active region during operation, and a transparent, at least partly electrically conductive cladding layer structure arranged directly on the semiconductor layer sequence in the vertical direction, wherein the cladding layer structure comprises at least a first cladding layer, a second cladding layer and a third cladding layer.