Hexagonal SiGe Light Emitter With Tunable Direct Band Gap
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Solution Overview
Problem
Efficient light emission from group-IV materials, particularly silicon, has been elusive due to their indirect band gap, and hexagonal Ge, while predicted to have a direct band gap, does not emit light efficiently due to a small matrix element.
Innovation Solution
A light-emitting component comprising a Hex-Si1−xGex compound material with a direct band gap is developed, structured to emit light with specific radiative emission coefficients and tunable wavelength, utilizing strained quantum well structures and a method involving Group III-V compound semiconductor nanowires and metalorganic vapor-phase epitaxy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If hexagonal Ge is used for light emission, then direct band gap emission is achieved, but the matrix element is small resulting in inefficient light emission
Solution Approach 1:
The patent changes the compositional parameter by using Hex-Si1-xGex alloys with varying Ge content (x=0.2 to 1.0) to optimize the direct band gap emission properties. By adjusting the Si/Ge ratio, the material achieves both direct band gap characteristics and improved matrix element for efficient light emission.
Solution Approach 2:
The patent employs composite Hex-Si1-xGex alloy materials combining silicon and germanium in hexagonal crystal structure. This composite approach leverages the direct band gap of hexagonal Ge while incorporating Si to enhance the optical matrix element and achieve efficient light emission.
2Productivity
If Hex-Si1−xGex compound material is used, then efficient light emission with sub-nanosecond recombination lifetime is achieved, but manufacturing complexity increases
Solution Approach 1:
The patent achieves multi-functionality by integrating both light emission and absorption capabilities in the same Hex-Si1-xGex material system. The material can be configured for different wavelengths (1.8-7.0 μm) and applications (emission or absorption) without requiring fundamentally different material systems, simplifying manufacturing.
Solution Approach 2:
The patent uses parameter changes in composition (x value) and crystal structure (hexagonal phase) to achieve different optical properties from the same base material system, allowing tuning of emission wavelength and efficiency without changing the fundamental material approach.
3Adaptability or versatility
If strained quantum well structures are used, then tunable wavelength emission between 1.5 μm and 7.0 μm is achieved, but structural complexity increases
Solution Approach 1:
The patent applies local quality by creating strained quantum well structures with specific composition gradients and thickness variations in the Hex-Si1-xGex material. Different regions of the structure have different compositions to achieve wavelength tuning while maintaining overall structural feasibility.
Solution Approach 2:
The patent exploits the quantum confinement effect in nanoscale quantum well structures, adding a dimensional constraint (quantum confinement in growth direction) to tune optical properties. This dimensional approach enables wavelength tuning from 1.5 to 7.0 μm through controlled layer thickness rather than bulk material changes.
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 achieves efficient light emission with sub-nanosecond recombination lifetime and tunable wavelength, comparable to direct band gap III-V semiconductors, enabling novel optoelectronic devices and integration with silicon technology.
Implementation Method 1
Hex-Si1−xGex compound material having a direct band gap for emitting light
Implementation Method 2
exhibits direct band gap emission with a sub-nanosecond recombination lifetime
Implementation Method 3
Hex-Si1−xGex compound material having a direct band gap for absorbing light
Implementation Method 4
growing one or more Group III-V compound semiconductor nanowires
Implementation Method 5
Group 11 element catalyst assisted chemical vapor deposition process
Implementation Method 6
growing a SixGe1−x shell epitaxially over the one or more Group III-V compound semiconductor nanowires
Implementation Method 7
Metalorganic vapor-phase epitaxy, MOVPE, process
Data Source
AI summary
The invention relates to a light-emitting component comprising a light-emitting section consisting of a Hex-Si1−xGex compound material, said Hex-Si1−xGex compound material having a direct band gap for emitting light.The invention also pertains to a light-absorbing component comprising a light-absorbing section consisting of a Hex-S1−xGex compound material, said Hex-Si1−xGex compound material having a direct band gap for absorbing light.