LED with 3D Nano-Structures for Enhanced Light Extraction
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Solution Overview
Problem
The extraction efficiency of light emitting diodes (LEDs) is low due to a limited 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 and semiconductor layers featuring three-dimensional nano-structures, which increase the contact area between the semiconductor layers and the active layer, enhancing electron-hole recombination and photon extraction efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the contact area between the N-type semiconductor layer and the active layer is increased, then the electron-hole recombination density is improved, but the device structure becomes more complex
Solution Approach 1:
The patent transforms the flat two-dimensional contact interface between the N-type semiconductor layer and active layer into a three-dimensional nano-structure surface. By creating vertical nano-pillars or nano-cones, the contact area is dramatically increased from a planar surface to a multi-dimensional nanoscale architecture, enabling higher electron-hole recombination density without simply expanding the lateral device footprint.
Solution Approach 2:
The patent introduces a porous or nanoscale structured interface between the N-type semiconductor layer and the active layer. The porous nano-structures provide increased surface area for carrier recombination while maintaining a compact overall device structure, effectively increasing the functional contact area without proportionally increasing device complexity.
2Quantity of substance
If the contact area between the N-type semiconductor layer and the active layer is increased, then the photon emission density is improved, but the manufacturing process becomes more difficult
Solution Approach 1:
The patent employs vertical nano-structure formation through controlled epitaxial growth or nanoscale etching processes, transforming a simple planar interface into a three-dimensional nanoscale architecture. This approach increases photon emission density by enhancing carrier recombination at the nano-structured interface while using established semiconductor manufacturing techniques.
Solution Approach 2:
The patent modifies the physical and chemical parameters of the semiconductor layers during epitaxial growth to form nano-structures with controlled dimensions, shapes, and distributions. By adjusting growth rates, temperatures, and precursor ratios, the nano-structure parameters are optimized to maximize photon emission while maintaining manufacturability through conventional semiconductor processing.
3Productivity
If the three-dimensional nano-structures are implemented, then the light extraction efficiency is improved, but the device complexity increases
Solution Approach 1:
The patent introduces three-dimensional nano-structures at the semiconductor layer interfaces to enhance light extraction efficiency. The vertical nano-pillars or nano-cones create multiple internal reflections and scattering centers that increase the optical path length and improve light extraction without requiring complex external optical components.
Solution Approach 2:
The three-dimensional nano-structures are designed to self-optimize light extraction through their geometric properties. The nano-structures inherently provide anti-reflective characteristics, enhanced scattering, and improved coupling to waveguide modes, allowing the structure itself to perform the light extraction enhancement function without additional external optical elements.
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 use of three-dimensional nano-structures on the semiconductor layers increases the electron-hole recombination density and improves light extraction efficiency, leading to a more effective emission of photons.
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 surface of the first semiconductor layer defines a plurality of three-dimensional nano-structures. The plurality of three-dimensional nano-structures increases the contact area between the first semiconductor layer and the active layer.
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. The first semiconductor layer includes a first surface and a second surface. The active layer and the second semiconductor layer are stacked on the second surface in that order, and a surface of the second semiconductor layer away from the active layer is configured as the light emitting surface. A first electrode electrically is connected with the first semiconductor layer. A second electrode is electrically connected with the second semiconductor layer. A number of first three-dimensional nano-structures are located on the second surface of the first semiconductor layer. A number of second three-dimensional nano-structures are located on a surface of the active layer contacting the second semiconductor layer, and a cross section of each of the three-dimensional nano-structures is M-shaped.