Nitride Semiconductor Light Emitting Element With Graded Mg Concentration Layers
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Solution Overview
Problem
Current semiconductor light emitting elements using nitride semiconductors face challenges in achieving high efficiency due to limitations in Mg concentration and Al composition ratios, leading to diffusion issues and reduced luminous efficiency.
Innovation Solution
The semiconductor light emitting element incorporates a stacked structure with specific Mg concentration gradients and Al composition ratios in layers, including a first layer with low Mg concentration, a second layer with high Mg concentration, and a third layer with intermediate Mg concentration, to control Mg diffusion and enhance luminous efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Mg concentration is increased to improve carrier injection efficiency, then luminous efficiency improves, but Mg diffusion increases causing crystal quality degradation
Solution Approach 1:
The patent divides the semiconductor layer into multiple stacked layers with different Mg concentrations. The first layer has low Mg concentration (0.01-0.1 at%) to maintain crystal quality, the second layer has high Mg concentration (0.1-5 at%) to provide carriers, and the third layer has intermediate Mg concentration (0.01-0.1 at%) to suppress diffusion. This segmentation allows each layer to perform its specific function without compromising overall device performance.
Solution Approach 2:
Different regions of the semiconductor structure are assigned different Mg concentrations tailored to their specific functions. The light-emitting region (first layer) maintains low Mg concentration for high crystal quality, while the carrier injection region (second layer) uses high Mg concentration. This local quality differentiation resolves the contradiction by allowing high Mg concentration only where needed for carrier injection while protecting the light-emitting region from diffusion damage.
2Illumination intensity
If Al composition ratio is increased to adjust bandgap energy, then light emission wavelength is controlled, but manufacturing precision becomes more difficult
Solution Approach 1:
The patent segments the Al composition control across multiple layers. The first layer uses low Al composition (0-0.2) for easy manufacturing and high crystal quality, the second layer uses high Al composition (0.2-0.8) to adjust bandgap and control emission wavelength, and the third layer uses low Al composition (0-0.2) to facilitate manufacturing. This segmentation allows wavelength control in the second layer without requiring high precision throughout the entire structure.
Solution Approach 2:
The patent changes the Al composition parameter across different layers to achieve both wavelength control and manufacturing ease. By concentrating the Al composition adjustment in the second layer while keeping the first and third layers with low Al content, the patent simplifies the manufacturing precision requirements while still achieving the desired light emission wavelength through bandgap engineering in the intermediate layer.
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 configuration effectively suppresses Mg diffusion, maintains high crystallinity, and increases luminous efficiency by optimizing the bandgap energies and carrier injection efficiency across the layers.
Implementation Method 1
effectively suppresses Mg diffusion
Implementation Method 2
semiconductor light emitting element includes an n-type semiconductor layer including a nitride semiconductor, a p-type semiconductor layer including a nitride semiconductor, a light emitting unit
Data Source
AI summary
According to one embodiment, a semiconductor light emitting element includes an n-type semiconductor layer including a nitride semiconductor, a p-type semiconductor layer including a nitride semiconductor, a light emitting unit, a first layer, a second layer, and a third layer. The light emitting unit is provided between the n-type and p-type semiconductor layers, and includes a first well layer including a nitride semiconductor. The first layer is provided between the first well layer and the p-type semiconductor layer, and includes Alx1Ga1-x1-y1Iny1N having a first Mg concentration. The second layer is provided between the first layer and the p-type semiconductor layer, and includes Alx2Ga1-x2-y2Iny2N having a second Mg concentration higher than the first Mg concentration. The third layer is provided between the second layer and the p-type semiconductor layer, and includes Alx3Ga1-x3-y3Iny3N having a third Mg concentration higher than the first Mg concentration and lower than the second Mg concentration.