LED Light Extraction via Micro/Nano Rugged Anti-Reflection Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current LED apparatuses suffer from poor light-emitting efficiency due to total reflection of light, which is exacerbated by the mismatch in refractive indices between the p-type semiconductor layer, current spreading layer, and air, leading to decreased luminance and increased heat.
Innovation Solution
The introduction of a micro/nano rugged layer and an anti-reflection layer with refractive indices between that of the epitaxial multilayer and air, along with the use of micro/nano particles, to reduce total reflection and enhance light output efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If light is emitted from the active layer through the p-type semiconductor layer and current spreading layer, then the LED structure is simple, but total reflection occurs due to refractive index mismatch, decreasing light output efficiency
Solution Approach 1:
The patent introduces a micro/nano rugged layer as an intermediary between the epitaxial multilayer and air. This layer has a refractive index that is intermediate between the semiconductor material and air, serving as a transition medium to reduce total reflection and improve light extraction efficiency without significantly complicating the overall device structure.
Solution Approach 2:
The patent changes the refractive index parameter by introducing the micro/nano rugged layer with an intermediate refractive index. This parameter change creates a gradual transition from the high refractive index semiconductor material to the low refractive index air, reducing the abrupt interface that causes total reflection and thereby improving light output efficiency.
2Loss of energy
If a micro/nano rugged layer and anti-reflection layer are added to reduce total reflection, then light output efficiency increases, but device complexity increases
Solution Approach 1:
The micro/nano rugged layer acts as an intermediary structure that provides refractive index matching. By using this intermediate layer with appropriate refractive index properties, the patent achieves improved light extraction while maintaining a relatively simple overall structure compared to more complex multi-layer anti-reflection coatings.
Solution Approach 2:
The patent applies the micro/nano rugged layer specifically at the light extraction interface where refractive index mismatch occurs, rather than modifying the entire device structure. This localized application addresses the specific problem of total reflection at the semiconductor-air interface while keeping the rest of the device simple.
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 solution effectively decreases total reflection, achieving refractive index matching and thereby increasing the light-emitting efficiency of the LED apparatus.
Implementation Method 1
the p-type semiconductor layer 123, the current spreading layer 13 and the refractive index of the air are not properly matched, the total reflection may occur when the light is being emitted out
Implementation Method 2
The refractive index of the micro/nano rugged layer ranges between the refractive index of the epitaxial multilayer and the refractive index of air. The refractive index of the anti-reflection layer ranges between the refractive index of the micro/nano rugged layer and the refractive index of air
Data Source
AI summary
A light-emitting diode (LED) apparatus includes an epitaxial multilayer, a micro/nano rugged layer and an anti-reflection layer. The epitaxial multilayer has a first semiconductor layer, an active layer and a second semiconductor layer in sequence. The micro/nano rugged layer is disposed on the first semiconductor layer of the epitaxial multilayer. The anti-reflection layer is disposed on the micro/nano rugged layer. In addition, a manufacturing method of the LED apparatus is also disclosed.