LED with Non-Uniform P-Type Resistance for Carrier Distribution
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Solution Overview
Problem
Conventional light emitting diodes (LEDs) suffer from insufficient light intensity due to inefficient carrier injection, where holes primarily inject under the electrode, limiting the light-emitting area and overall efficiency.
Innovation Solution
The LED design incorporates a second-type semiconductor layer with regions of different resistances and dopant distribution densities, along with a rough surface formed through ion implantation, allowing carriers to inject and combine more effectively across the light-emitting layer, enhancing light intensity and reducing total reflection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the area of the electrode above the P-type semiconductor layer is enlarged to allow carrier injection into more portions of the light emitting layer, then the carrier injection efficiency is improved, but the light emitting area is decreased due to the opaque material of the electrode
Solution Approach 1:
The patent applies local quality by creating regions with different resistance values within the P-type semiconductor layer. Specifically, a first region under the electrode has higher resistance while a second region has lower resistance. This non-uniform resistance distribution allows carriers to be effectively injected and distributed across different areas of the light emitting layer, resolving the contradiction between injection efficiency and light emitting area.
Solution Approach 2:
The patent changes the resistance parameter of the P-type semiconductor layer by introducing dopants with different distribution densities in different regions. The dopant concentration is adjusted to create the desired resistance profile, where the first region has higher resistance and the second region has lower resistance, enabling improved carrier distribution without sacrificing light emitting area.
2Productivity
If dopants are introduced to create different resistance regions in the P-type semiconductor layer, then carrier distribution is improved, but the device complexity increases
Solution Approach 1:
The patent segments the P-type semiconductor layer into distinct regions with different resistance characteristics. The layer is divided into a first region under the electrode with higher resistance and a second region with lower resistance. This segmentation is achieved through controlled dopant distribution, allowing independent optimization of carrier injection and distribution without requiring entirely new device structures.
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 approach increases light-emitting intensity and efficiency by ensuring carriers combine throughout the light-emitting layer, rather than just under the electrode, and decreases the probability of light reflection, resulting in improved LED performance.
Implementation Method 1
the second-type semiconductor layer has a first region with a first resistance and a second region with a second resistance smaller than the first resistance
Implementation Method 2
a rough surface formed through ion implantation
Data Source
AI summary
A light emitting diode and a fabricating method thereof are provided. The method including the steps of sequentially forming a first-type semiconductor layer, a light emitting layer and a second-type semiconductor layer with a first region and a second region on a substrate. Next, an ion implantation process is performed to make the resistance of the first region be larger than of the second region. Afterward, a first electrode is formed above the first region of the second-type semiconductor layer. Since the method uses the ion implantation process to make the inner resistance of the second-type semiconductor layer various, the light emitting intensity and efficiency may both be increased.