Light-Emitting Element with Segmented Electrodes for Current Dispersion
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Solution Overview
Problem
The existing semiconductor light-emitting element structure faces challenges in achieving improved luminous efficiency due to increased contact resistance and non-uniform light emission, primarily because the n electrode is directly stacked on the n-GaN layer, leading to a narrowed light-emitting layer and concentrated current density, which results in reduced light output and efficiency.
Innovation Solution
A light-emitting element design featuring a first conductivity type semiconductor layer, a light-emitting layer, a second conductivity type semiconductor layer, a transparent electrode layer, a reflecting electrode layer, and insulating tube layers, with discretely arranged first contacts that allow for efficient current dispersion and reduced contact area, enabling wider light emission and improved luminous efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the n electrode is directly stacked on the n-GaN layer to reduce contact resistance, then contact resistance is reduced, but the light-emitting layer area is narrowed and current density becomes concentrated
Solution Approach 1:
The n electrode is divided into multiple discrete contact regions arranged in a matrix pattern rather than a single continuous electrode. This segmentation allows current to disperse through multiple contact points while maintaining adequate contact area for low resistance, thereby resolving the contradiction between reducing contact resistance and preserving light-emitting layer area.
2Productivity
If the n electrode is directly stacked on the n-GaN layer, then current can be supplied efficiently, but current density becomes concentrated and light emission becomes non-uniform
Solution Approach 1:
The n electrode is segmented into multiple discrete contact regions arranged in a matrix pattern, which disperses current flow across multiple contact points. This segmentation maintains efficient current supply while preventing current concentration, thereby achieving uniform light emission across the light-emitting layer.
Solution Approach 2:
Different regions of the n electrode are designed with specific contact area and spacing to optimize local current distribution. The matrix arrangement of contact regions creates localized current injection points that collectively achieve uniform current density across the entire light-emitting layer, resolving the contradiction between current supply efficiency and emission uniformity.
3Ease of operation
If branch portions are added to the n electrode to expand current distribution, then current dispersion improves, but the light-emitting layer area is further corroded and luminous efficiency deteriorates
Solution Approach 1:
Instead of adding branch portions that would encroach on the light-emitting layer, the n electrode is segmented into multiple discrete contact regions arranged in a matrix. This approach achieves current dispersion through spatial distribution of contact points without requiring lateral extensions that would reduce the light-emitting layer area, thereby maintaining luminous efficiency while improving current dispersion.
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 design enhances luminous efficiency by enlarging the light-emitting layer area, reducing current density, and preventing light loss through efficient current distribution and light extraction, resulting in improved light output and emission uniformity.
Implementation Method 1
a transparent electrode layer, stacked on the second conductivity type semiconductor layer, transparent with respect to the emission wavelength of the light-emitting layer
Implementation Method 2
a reflecting electrode layer, stacked on the transparent electrode layer, reflecting light transmitted through the transparent electrode layer
Data Source
AI summary
In a light-emitting element (1), a light-emitting layer (4), a second conductivity type semiconductor layer (5), a transparent electrode layer (6), a reflecting electrode layer (7) and an insulating layer (8) are stacked in this order on a first conductivity type semiconductor layer (3), while a first electrode layer (10) and a second electrode layer (12) are stacked on the insulating layer (8) in an isolated state. The light-emitting element (1) includes a plurality of insulating tube layers (9), discretely arranged in plan view, passing through the reflecting electrode layer (7), the transparent electrode layer (6), the second conductivity type semiconductor layer (5) and the light-emitting layer (4) continuously from the insulating layer (8) and reaching the first conductivity type semiconductor layer (3), first contacts (11), continuous from the first electrode layer (10), connected to the first conductivity type semiconductor layer (3) through the insulating layer (8) and the insulating tube layers (9), and second contacts (13), continuous from the second electrode layer (12), passing through the insulating layer (8) to be connected to the reflecting electrode layer (7).