LED with M-shaped Nanostructures for Light Extraction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The extraction efficiency of light emitting diodes (LEDs) is low due to a small contact area between the N-type semiconductor layer and the active layer, resulting in low electron-hole recombination density and sparse photon emission.
Innovation Solution
The implementation of a light emitting diode with a substrate featuring three-dimensional nano-structures that increase the contact area between the semiconductor layers, enhancing electron-hole recombination and photon extraction efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the contact area between the N-type semiconductor layer and the active layer is increased, then the electron-hole recombination density and photon emission increase, but the device structure becomes more complex
Solution Approach 1:
The patent applies dimensionality change by transitioning from a planar contact interface to a three-dimensional nanostructure surface. The N-type semiconductor layer is formed with three-dimensional nanostructures (such as nanowires, nanodots, or nanopillars) that increase the contact area with the active layer in the vertical dimension, thereby enhancing electron-hole recombination density and photon emission efficiency without significantly increasing lateral device footprint or overall structural complexity
Solution Approach 2:
The patent utilizes porous or highly textured nanostructured surfaces on the N-type semiconductor layer to maximize the contact area with the active layer. These porous nanostructures provide a large surface area for carrier recombination and light generation, improving extraction efficiency while maintaining a compact device form factor
2Productivity
If three-dimensional nano-structures are introduced to increase contact area, then light extraction efficiency improves, but manufacturing precision requirements increase
Solution Approach 1:
The patent optimizes key parameters of the three-dimensional nanostructures, including size (50-500 nm diameter), spacing (100-1000 nm between structures), and depth (50-200 nm), to achieve optimal light extraction efficiency. By carefully controlling these parameters within specific ranges, the patent balances the need for enhanced light extraction with achievable manufacturing precision using conventional semiconductor fabrication techniques
Solution Approach 2:
The patent employs dynamic control during the fabrication process, particularly during the formation of three-dimensional nanostructures using techniques such as selective area growth, nanosphere lithography, or self-assembly processes. These methods allow for precise control over nanostructure formation while accommodating normal variations in manufacturing conditions
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 three-dimensional nano-structures improve the light extraction efficiency of LEDs by increasing the contact area and altering the path of photons, leading to increased photon emission and improved reliability.
Implementation Method 1
In operation, a positive voltage and a negative voltage are applied respectively to the P-type semiconductor layer and the N-type semiconductor layer. Thus, holes in the P-type semiconductor layer and photons in the N-type semiconductor layer can enter the active layer and combine with each other to emit visible light.
Implementation Method 2
The three-dimensional nano-structures improve the light extraction efficiency of LEDs by increasing the contact area and altering the path of photons
Data Source
AI summary
A light emitting diode including a substrate, a first semiconductor layer, an active layer, and a second semiconductor layer is provided. A surface of the substrate away from the active layer is configured as the light emitting surface. The first semiconductor layer includes a first surface and a second surface, and the first surface is connected to the substrate. The active layer and the second semiconductor layer are stacked on the second surface in that order. A first electrode electrically is connected with the first semiconductor layer. A second electrode is electrically connected with and covers a surface of the second semiconductor layer. A number of three-dimensional nano-structures are located on the surface of the first surface of the first semiconductor layer and the light emitting surface, and a cross section of each of the three-dimensional nano-structure is M-shaped.