Bent Nanowire Device for Enhanced Light Emission

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Solution Overview

Problem

Conventional nanowire devices with straight perpendicular or tilted nanowires face limitations in light emission efficiency and manufacturing challenges, particularly in integrating III-V optoelectronic materials with the Si platform and achieving efficient light emission normal to the substrate.

Innovation Solution

A nanowire device with a bent shape, comprising a core region of semiconductor material and a bending region of different material composition, inducing strain to deviate the nanowire from the substrate normal, enhancing light coupling efficiency and carrier recombination by positioning the active region in a tensely strained portion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If straight perpendicular nanowires are used, then light emission in the direction perpendicular to the substrate is achieved, but light coupling efficiency is significantly reduced

Engineering Contradiction:
Improvelight emission efficiencyVSAvoidlight coupling efficiency
Core Design Contradiction:
Illumination intensityVSEase of manufacture

Solution Approach 1:

The patent applies curvature by bending the nanowire away from the substrate normal direction. This curved configuration increases the interaction length between light and the nanowire, thereby enhancing light coupling efficiency while maintaining perpendicular emission direction relative to the substrate

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Illumination intensity

If straight tilted nanowires are used, then light absorption and extraction is improved, but deposition of shells becomes difficult due to shadowing effects

Engineering Contradiction:
Improvelight absorption and extractionVSAvoidshell deposition
Core Design Contradiction:
Illumination intensityVSEase of manufacture

Solution Approach 1:

The bent nanowire configuration eliminates shadowing effects that plague tilted straight nanowires. The curved geometry allows shell material to be deposited uniformly around the entire nanowire surface, enabling complete heterostructure formation while maintaining improved light absorption and extraction properties

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Area of stationary object

If nanowires with diameter smaller than wavelength are used, then footprint is reduced, but light coupling in the normal direction is significantly reduced

Engineering Contradiction:
ImprovefootprintVSAvoidlight coupling efficiency
Core Design Contradiction:
Area of stationary objectVSIllumination intensity

Solution Approach 1:

The bent nanowire design compensates for the small diameter limitation by increasing the effective interaction length through curvature. The bent configuration allows light to travel along the curved path, effectively increasing the coupling length without increasing the lateral footprint, thereby maintaining compact size while improving light coupling efficiency

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 bent nanowire device achieves enhanced light emission efficiency normal to the substrate, allows for longer emission wavelengths, and simplifies manufacturing by inherently obtaining the curved shape through material combination, improving carrier transport and light coupling compared to conventional devices.

Implementation Method 1

The bending region comprises a different material or material composition and is adapted for inducing strain in the nanowire, in particular at an interface of the core region, such that the at least one nanowire is bent

Methodology Applied
Scientific EffectStrain: Deformation

Implementation Method 2

The active region is located in a tensely strained portion of the at least one nanowire, improving carrier transport and recombination

Methodology Applied
Scientific EffectCarrier drift: Electrophoresis

Data Source

PatentEP3367447B1Nanowire device and method of manufacturing thereof
Publication Date: 2019.10.09 FORSCHUNGSVERBUND BERLIN EV
  • EP3367447B1 patent drawingFigure 1~4
  • EP3367447B1 patent drawingFigure 5~6
  • EP3367447B1 patent drawingFigure 7~8

AI summary

A nanowire device (10), in particular for optical or optoelectronic applications, comprises at least one nanowire (1) standing on a substrate (2), wherein the at least one nanowire (1) includes a core region (3) and a bending region (4) being adapted for inducing strain in the at least one nanowire (1) such that the at least one nanowire (1) is bent in a bending direction deviating from the normal direction of the substrate (2), wherein the at least one nanowire (1) includes an active region (5) being located in a tensely strained portion of the at least one nanowire (1), wherein the tensely strained portion has a tensile strain compared to an average strain in the at least one nanowire (1), and the core region (3) and the active region (5) provide a heterostructure being configured for light emission by carrier recombination. Furthermore, a method of manufacturing the nanowire device is described.