Nitride Light-Emitting Element Structure to Block Electron Overflow
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Solution Overview
Problem
Existing high-output laser elements using nitride semiconductors face reduced carrier injection efficiency due to thermal excitation of electrons overflowing into the p-side semiconductor layer.
Innovation Solution
A light-emitting element configuration with specific semiconductor layers, including a high Al composition ratio second semiconductor layer and a third semiconductor layer with a gradually decreasing Al composition ratio, effectively blocks electron overflow and enhances carrier injection efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an electron blocking layer with high Al composition ratio is inserted to suppress electron overflow, then carrier injection efficiency is improved, but device complexity increases
Solution Approach 1:
The electron blocking layer is divided into multiple semiconductor layers (second, third, and fourth layers) with different Al composition ratios. The second layer has a higher Al composition ratio than the third layer, which in turn has a higher ratio than the fourth layer. This segmentation allows each layer to perform electron blocking functions at different positions and with different effectiveness, improving overall carrier injection efficiency while managing device complexity through functional distribution.
Solution Approach 2:
Different regions of the electron blocking layer are assigned different Al composition ratios tailored to their specific functions. The second layer closest to the active layer uses a higher Al composition ratio to strongly block electrons, while the third and fourth layers use progressively lower ratios to balance blocking effectiveness with carrier transport requirements. This local quality optimization improves carrier injection efficiency without uniformly increasing device complexity throughout the entire structure.
2Power
If the Al composition ratio is increased to enhance electron blocking, then power output is improved, but manufacturing precision requirements increase
Solution Approach 1:
The Al composition ratio is varied across different layers of the electron blocking structure. The second layer has a higher Al composition ratio than the third layer, which has a higher ratio than the fourth layer. This parameter change approach allows optimization of electron blocking performance for high power output while distributing the manufacturing precision requirements across multiple layers with different specifications, making the overall manufacturing process more manageable.
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 configuration improves carrier injection efficiency, allowing for higher power output at the same injection current and enhanced power conversion efficiency by effectively blocking electron overflow.
Implementation Method 1
an electron blocking layer having a band gap larger than that of the p-side semiconductor layer is inserted between the active layer and the p-side semiconductor layer
Data Source
Figure 1
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Figure 3~4
AI summary
A light-emitting element includes: a first semiconductor layer, a second semiconductor layer, a third semiconductor layer, and a fourth semiconductor layer in this order. The first semiconductor layer is Alx1Iny1Ga1-x1-y1N (0 ≤ x1 ≤ 1, 0 ≤ y1 ≤ 1, 0 ≤ x1 + y1 ≤ 1), the second semiconductor layer is Alx2Iny2Ga1-x2-y2N (0 ≤ x2 ≤ 1, 0 ≤ y2 ≤ 1, 0 ≤ x2 + y2 ≤ 1), the third semiconductor layer is Alx3Iny3Ga1-x3-y3N (0 ≤ x3 ≤ 1, 0 ≤ y3 ≤ 1, 0 ≤ x3 + y3 ≤ 1), and the fourth semiconductor layer is Alx4Iny4Ga1-x4-y4N (0 ≤ x4 ≤ 1, 0 ≤ y4 ≤ 1, 0 ≤ x4 + y4 ≤ 1).