LED Nano-Structure Contact Area Enhancement
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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 formation of three-dimensional nano-structures on the surface of the semiconductor layer increases the contact area with the active layer, enhancing electron-hole recombination and photon extraction efficiency by creating a patterned surface for the LED structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a typical LED structure with flat semiconductor layers is used, then the device structure is simple and easy to manufacture, but the contact area between the N-type semiconductor layer and the active layer is small, resulting in low electron-hole recombination density and low light extraction efficiency
Solution Approach 1:
The patent transforms the flat two-dimensional interface between the N-type semiconductor layer and the active layer into a three-dimensional patterned surface with protrusions and recesses. This dimensional change significantly increases the contact area and interaction volume between the semiconductor layer and active layer, thereby improving electron-hole recombination density and light extraction efficiency while maintaining manufacturing feasibility through standard lithography and etching processes
Solution Approach 2:
The patent divides the flat interface into multiple discrete protrusion structures arranged in an array. This segmentation increases the total surface area and creates multiple localized regions for enhanced electron-hole recombination and photon extraction, effectively resolving the contradiction between manufacturing simplicity and extraction efficiency
2Productivity
If the contact area between the N-type semiconductor layer and the active layer is increased by creating three-dimensional nano-structures, then the light extraction efficiency is improved, but the device structure becomes more complex
Solution Approach 1:
The patent optimizes key parameters of the three-dimensional structures including protrusion height (50-500 nm), width (50-500 nm), and spacing (10-100 nm) to achieve maximum light extraction efficiency. By carefully controlling these dimensional parameters within specific ranges, the patent enhances extraction performance while keeping the structural complexity manageable and compatible with existing manufacturing capabilities
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 increased contact area and patterned surface design improve the light extraction efficiency of the LED, leading to higher photon emission and enhanced performance.
Implementation Method 1
LEDs are semiconductors that convert electrical energy into light. 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.
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 substrate includes an epitaxial growth surface and a light emitting surface. The first semiconductor layer, the active layer and the second semiconductor layer is stacked on the epitaxial growth 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 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 aligned side by side, and a cross section of each of the three-dimensional nano-structure is M-shaped.