LED Chip Wall Structure for Light Propagation Efficiency
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Solution Overview
Problem
Conventional LED chips suffer from low external quantum efficiency due to inefficient light propagation, resulting in directional emission with a small angle of dispersion, which limits their application in displays and illumination.
Innovation Solution
The LED chip design incorporates a substrate, semiconductor device layer, and a wall structure with a continuous pattern that surrounds the active layer, along with electrodes, to enhance light propagation and emission efficiency. The wall structure, comprising a semiconductor epitaxial layer and cap layer, is formed to reflect light laterally, increasing the external quantum efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional LED chip structure is used, then manufacturing is simple, but external quantum efficiency is low due to poor light propagation
Solution Approach 1:
The patent introduces a wall structure with vertical dimension that extends above the semiconductor device layer. This vertical extension creates a new dimensional space for light reflection and redirection, transforming the conventional planar light emission into a three-dimensional light management system that improves external quantum efficiency without complicating the manufacturing process
2Productivity
If light is emitted in various directions, then light utilization is poor, but directional emission with small angle of dispersion is achieved
Solution Approach 1:
The wall structure acts as an intermediary element between the active layer and the external environment. It intercepts light emitted in various directions from the active layer and redirects it through reflection, serving as a mediator that transforms omnidirectional emission into more useful directional patterns while improving overall light utilization efficiency
3Loss of energy
If wall structure is added to improve light propagation, then external quantum efficiency increases, but device complexity increases
Solution Approach 1:
The wall structure is merged with the existing semiconductor device layer and electrode structure. By integrating the light-managing wall structure into the same fabrication process and spatial arrangement as the functional layers, the patent achieves improved external quantum efficiency while minimizing the increase in device complexity through unified structural design
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 enhanced light emitting efficiency of the LED chip allows for effective utilization of light in various directions, improving its external quantum efficiency and making it suitable for broader applications in displays and illumination.
Implementation Method 1
The wall structure, comprising a semiconductor epitaxial layer and cap layer, is formed to reflect light laterally, increasing the external quantum efficiency
Data Source
AI summary
An LED chip includes a substrate, a semiconductor device layer, a wall structure, and a number of electrodes. The semiconductor device layer is disposed on the substrate and includes a first-type doped semiconductor layer disposed on the substrate, an active layer disposed on a portion of the first-type doped semiconductor layer, and a second-type doped semiconductor layer disposed on the active layer and having a first top surface. The wall structure is disposed on the first-type doped semiconductor layer that is not covered by the active layer and surrounds the active layer. Besides, the wall structure has a second top surface higher than the first top surface of the second-type doped semiconductor layer. Additionally, the electrodes are disposed on and electrically connected with the first-type doped semiconductor layer and the second-type doped semiconductor layer.