Semiconductor Light Emitting Device Concave-Convex Interface
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Solution Overview
Problem
Semiconductor light emitting devices face challenges in achieving high light extraction efficiency due to flat interfaces between the light emitting layer and the bonding metal layer, which limits the reflection and scattering of light.
Innovation Solution
The implementation of concave-convex structures on the interfaces between the light emitting layer and the reflection metal layer, as well as on the light extraction surface, enhances light scattering and reflection, increasing the light extraction efficiency by reducing total reflection and increasing the area of the reflection surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a flat interface is provided between the light emitting layer and the bonding metal layer, then the device structure is simple and easy to manufacture, but the light extraction efficiency cannot be sufficiently increased
Solution Approach 1:
The patent applies curvature by forming concave-convex structures on the interface between the light emitting layer and the bonding metal layer. These curved surface features scatter downward light and increase the reflection surface area, thereby improving light extraction efficiency while maintaining manufacturing feasibility through standard semiconductor processing techniques
Solution Approach 2:
The patent creates a porous-like structure on the interface between the light emitting layer and the bonding metal layer through concave-convex formations. This increases the surface area and light scattering capability, allowing more light to be extracted from the device without significantly complicating the manufacturing process
2Loss of energy
If the reflection metal layer reflects downward light upward, then light extraction efficiency can be increased, but total reflection at the interface limits further improvement
Solution Approach 1:
The concave-convex structures on the interface create curved surfaces that scatter reflected light in multiple directions. This scattering effect reduces total reflection by redirecting light that would otherwise be totally reflected back into the light emitting layer, thereby further improving light extraction efficiency
Solution Approach 2:
The patent applies local quality by creating concave-convex structures specifically at the interface region between the light emitting layer and the bonding metal layer. This localized structural modification targets the area where total reflection occurs, scattering light locally to reduce total reflection effects while maintaining the overall device structure
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 results in improved light extraction efficiency, with luminance increases of up to 130% compared to comparative examples, making it suitable for applications in lighting equipment, display devices, and traffic signals.
Implementation Method 1
A plurality of interfaces, provided between the first conductivity type layer and the reflection metal layer, has at least first concave-convex structures... enhances light scattering and reflection
Implementation Method 2
The reflection metal layer may be, for example, a portion of a bonding metal layer connecting a semiconductor stacked structure including the light emitting layer... reflects a downward light emitted from the light emitting layer upward
Data Source
AI summary
According to one embodiment, a semiconductor light emitting device includes a light emitting layer, a first electrode, a first conductivity type layer, a second conductivity type layer, and a second electrode. The first electrode includes a reflection metal layer. The first conductivity type layer is provided between the light emitting layer and the first electrode. The second conductivity type layer has a first surface on the light emitting layer side and a second surface on an opposite side of the first surface. The second electrode is provided on the second surface of the second conductivity type layer. A plurarity of interfaces, provided between the first conductivity type layer and the reflection metal layer, has at least first concave-convex structures. A region of the second surface of the second conductivity type layer, where the second electrode is not provided, has second concave-convex structures.