Textured LED Structure via Anodized Metal Oxide Buffer
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Solution Overview
Problem
Conventional semiconductor light emitting diodes with textured structures on sapphire substrates face reduced light extraction efficiency due to crystal defects caused by lattice mismatch, leading to internal reflection and decreased performance.
Innovation Solution
A semiconductor light emitting diode with a textured structure layer formed from anodized metal oxide on a substrate, featuring a first semiconductor layer, an active layer, and a second semiconductor layer, which reduces stress and defect distribution by incorporating a non-planar structure that enhances light extraction efficiency and minimizes internal defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a textured structure is incorporated at the interface between the semiconductor layer and air layer to improve light extraction efficiency, then light extraction efficiency is improved, but crystal defects are generated due to lattice mismatch with sapphire substrate
Solution Approach 1:
The patent introduces a buffer layer as an intermediary between the sapphire substrate and the GaN-based semiconductor layers. This buffer layer mediates the lattice mismatch between the sapphire substrate and the semiconductor layers, preventing crystal defects from propagating into the active regions while allowing the textured structure to maintain its light extraction enhancement function.
Solution Approach 2:
The patent segments the interface structure by introducing a textured structure layer as a separate functional layer between the substrate and the semiconductor layers. This segmentation allows the textured structure to perform its light extraction function independently without directly causing lattice mismatch defects in the semiconductor layers.
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 increases light extraction efficiency and stabilizes the semiconductor light emitting diode by reducing internal crystal defects and improving the uniformity of stress distribution, leading to enhanced operational stability and lifespan.
Implementation Method 1
If the light enters at an angle greater than the predetermined angle, the light is totally internally reflected at the flat interface, thereby greatly reducing the light extraction efficiency.
Implementation Method 2
Travel of light through an interface between material layers having different refractive indexes is limited by the refractive indices of the material layers.
Implementation Method 3
A light emitting diode (LED) converts electrical energy into infrared rays or visible light using the characteristics of a compound semiconductor. The light emitting diode is a kind of electroluminescent (EL) device
Data Source
AI summary
Provided is a semiconductor light emitting diode having a textured structure formed on a substrate. In a method of manufacturing the semiconductor light emitting diode, a metal layer is formed on the substrate, and a metal oxide layer having holes is formed by anodizing the metal layer. The metal oxide layer itself can be used as a textured structure pattern, or the textured structure pattern can be formed by forming holes in the substrate or a material layer under the metal oxide layer corresponding to the holes of the metal oxide layer. The manufacture of the semiconductor light emitting diode is completed by sequentially forming a first semiconductor layer, an active layer, and a second semiconductor layer on the textured structure pattern.