LED Epitaxial Stack Reflection Structure With Diffusion Barrier
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Solution Overview
Problem
Conventional light-emitting devices face issues with high voltage due to material diffusion between the ohmic contact layer and the adhesion layer, affecting the ohmic contact between the semiconductor epitaxial stack and leading to reduced light-emitting efficiency.
Innovation Solution
Incorporating a diffusion barrier layer between the ohmic contact layer and the adhesion layer to prevent metal diffusion, along with a light-transmissive dielectric layer and a metal reflection layer to enhance light-emitting efficiency, the light-emitting device includes a semiconductor epitaxial stack, ohmic contact layer, adhesion layer, and metal reflection layer, with the diffusion barrier layer positioned between the ohmic contact and adhesion layers to maintain surface uniformity and improve reflectivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a light-transmissive dielectric layer and metal reflection layer are provided to improve light-emitting efficiency, then light-emitting efficiency is improved, but material diffusion between the ohmic contact layer and adhesion layer occurs causing high voltage
Solution Approach 1:
A diffusion barrier layer is introduced as an intermediary between the ohmic contact layer and the adhesion layer. This barrier layer prevents direct contact and material diffusion between the ohmic contact layer and adhesion layer, thereby maintaining ohmic contact quality while allowing the light-transmissive dielectric layer and metal reflection layer to function for improving light-emitting efficiency.
2Strength
If the adhesion layer is disposed directly on the light-transmissive dielectric layer to improve adhesion, then adhesion between layers is improved, but material diffusion occurs affecting ohmic contact
Solution Approach 1:
The diffusion barrier layer serves as a mediator between the adhesion layer and the light-transmissive dielectric layer. It allows the adhesion layer to maintain strong adhesion to the dielectric layer while preventing harmful material diffusion toward the ohmic contact layer, thus eliminating the harmful effect without compromising adhesion strength.
3Reliability
If metal diffusion is prevented by adding a diffusion barrier layer, then ohmic contact quality is improved, but device structure becomes more complex
Solution Approach 1:
The device structure is segmented into distinct functional layers, with the diffusion barrier layer being a separate, thin layer between the adhesion layer and light-transmissive dielectric layer. This segmentation allows each layer to perform its specific function independently, preventing material diffusion while maintaining overall structural organization and not significantly increasing 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
The diffusion barrier layer effectively prevents metal diffusion, reducing high voltage issues and enhancing light-emitting efficiency by ensuring uniformity of the metal reflection layer and improving the overall performance of the light-emitting device.
Implementation Method 1
a metal reflection layer and a light-transmissive dielectric layer are usually provided on one side of the metal bonding layer, and cooperatively form an ODR reflective structure which reflects light from the metal bonding layer to the light-emitting surface
Implementation Method 2
The diffusion barrier layer is disposed between the ohmic contact layer and the adhesion layer
Data Source
AI summary
A light-emitting device includes: a semiconductor epitaxial stack that has a first surface and a second surface, and includes a first semiconductor layer, an active layer, and a second semiconductor layer sequentially stacked on one another in a direction from the second surface to the first surface; a light-transmissive dielectric layer that is disposed on the second surface and that has through holes; an ohmic contact layer that is formed in the through holes and that is in contact with the first semiconductor layer; an adhesion layer that is disposed on the light-transmissive dielectric layer opposite to the semiconductor epitaxial stack; a metal reflection layer that is disposed on the adhesion layer opposite to the semiconductor epitaxial stack; and a diffusion barrier layer that is disposed between the ohmic contact layer and the adhesion layer. A light-emitting apparatus and a method for manufacturing the light-emitting device are also provided.