Semiconductor Light Emitting Element Protrusion Electrodes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor light emitting elements face issues with increased resistance and decreased light extraction efficiency due to concentrated electric current and flat surfaces that lead to light reflection, respectively.
Innovation Solution
A semiconductor light emitting element design featuring a semiconductor laminate with a first semiconductor layer, an active layer, and a second semiconductor layer, where the first electrode includes protrusions penetrating the second semiconductor layer and active layer, connected to the first semiconductor layer through insulation-covered protrusion tips, and the first semiconductor layer has recesses on its surface to sandwich areas above the protrusions, with a distance between recesses wider than the protrusion tip width.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the upper face of the first semiconductor layer is etched to form a rough surface, then light extraction efficiency is improved, but electric current becomes concentrated causing resistance to increase
Solution Approach 1:
The invention applies different surface treatments to different regions of the first semiconductor layer. The light-emitting regions (first regions) are etched to form rough surfaces for improved light extraction, while the electrode contact regions (second regions) are kept flat to ensure good electrical contact and prevent current concentration. This local differentiation resolves the contradiction between light extraction efficiency and electrical resistance.
2Reliability
If protrusions penetrate through the second semiconductor layer and active layer to connect to the first semiconductor layer, then current flow is improved, but the structure becomes more complex
Solution Approach 1:
The first electrode is segmented into multiple protrusions that penetrate through the second semiconductor layer and active layer to contact the first semiconductor layer. This segmentation allows current to flow through multiple discrete contact points, improving current distribution and reducing resistance while maintaining a manageable structural complexity through repetitive modular elements.
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
The light emitting element (1) including: a semiconductor laminate (19) including a first layer (19a), an active layer (19c) and a second layer (19b); a first electrode (15) including protrusions (151) that penetrate the second layer and the active layer, the first electrode connected to the first layer via the protrusions; a second electrode (17) connected to the second layer on an lower face of the second layer; and an insulation film (16) between the protrusions and the semiconductor laminate, wherein the protrusions each include a protrusion body (151a) covered with the insulation film and a protrusion tip (151b), an upper face and a side face of the protrusion tip being exposed from the insulation film, the first layer includes recesses (191) arranged on an upper face of the first layer so as to sandwich first areas located above the respective the protrusions, and a distance between the recesses sandwiching the first area is larger than a width of the protrusion tip.