Nitride Light-Emitting Element Structure for Electron Overflow Blocking
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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 composition gradient, is implemented to enhance carrier injection efficiency by effectively blocking electron overflow.
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 due to multiple semiconductor layers with specific composition ratios
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 specific functions in suppressing electron overflow while managing device complexity through systematic composition gradients.
Solution Approach 2:
Different regions of the electron blocking layer are assigned different Al composition ratios tailored to their specific functions. The second layer closer to the active layer uses a higher Al composition ratio for strong electron blocking, while the third and fourth layers use progressively lower ratios to balance blocking effectiveness with carrier transport requirements, optimizing local properties for each position.
2Power
If the Al composition ratio is increased to enhance electron blocking, then power output is improved, but manufacturing precision requirements increase due to strict composition ratio specifications
Solution Approach 1:
The invention employs systematic changes in Al composition ratio across different layers (second layer: highest, third layer: intermediate, fourth layer: lowest) to achieve effective electron blocking. This parameter gradient approach allows optimization of power output while distributing the manufacturing precision requirements across multiple layers with progressively relaxed specifications, making high-power operation achievable without excessive manufacturing difficulty.
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 and reducing non-radiative recombination.
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
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).