Optoelectronic Device Electrode Spacing for Light Extraction
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Solution Overview
Problem
Conventional optoelectronic devices, such as LEDs, suffer from reduced light extraction efficiency due to the presence of a diffusion barrier layer in the electrode structure, which affects the reflectivity and overall performance.
Innovation Solution
The proposed optoelectronic device incorporates a semiconductor stack with a reflective electrode and an insulative layer, featuring a specific height difference and spacing between metal layers to enhance light extraction efficiency, achieved through a manufacturing process involving physical vapor deposition and etching techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a diffusion barrier layer is added to the electrode structure, then the electrode's protective function is improved, but the light extraction efficiency deteriorates due to reduced reflectivity
Solution Approach 1:
The electrode structure is segmented into multiple functional layers: a reflective layer (first metal layer) for light extraction, a diffusion barrier layer (second metal layer) for protection, and an insulative layer. This segmentation allows each layer to perform its specific function independently, resolving the contradiction between protection and light extraction efficiency.
Solution Approach 2:
Different regions of the electrode structure are assigned different properties: the reflective layer has high reflectivity for light extraction, while the diffusion barrier layer provides protective properties. The insulative layer is positioned locally to prevent electrical shorts without affecting light extraction paths.
2Ease of manufacture
If the height difference between metal layers and insulative layer is large, then the manufacturing process is simpler, but the light extraction efficiency deteriorates due to increased spacing
Solution Approach 1:
The patent optimizes the height difference parameter between the metal layers and the insulative layer to a specific range (less than 1 μm). This parameter optimization achieves a balance between manufacturing feasibility and light extraction efficiency, resolving the contradiction between ease of manufacture and energy loss.
3Reliability
If the space between the first electrode and insulative layer is increased, then the electrical insulation is improved, but the light extraction efficiency deteriorates
Solution Approach 1:
The insulative layer is strategically positioned to provide electrical insulation only where needed (preventing shorts between adjacent electrodes), while maintaining minimal spacing in light extraction regions. This local optimization resolves the contradiction between insulation requirements and light extraction efficiency.
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 significantly improves light extraction efficiency by optimizing the electrode design, allowing for better reflectivity and heat dissipation, thereby enhancing the performance of optoelectronic devices like LEDs.
Implementation Method 1
the first electrode further includes a reflective layer
Implementation Method 2
achieved through a manufacturing process involving physical vapor deposition and etching techniques
Data Source
AI summary
An optoelectronic device includes a semiconductor stack, including a first semiconductor layer, an active layer formed on the first semiconductor layer, and a second semiconductor layer; a first metal layer formed on a top surface of the second semiconductor layer; a second metal layer formed on a top surface of the first semiconductor layer; an insulative layer formed on the top surface of the first semiconductor layer and the top surface of the second semiconductor layer; wherein a space between a sidewall of the first metal layer and a sidewall of the semiconductor stack is less than 3 μm.