Multi-bandgap Nanowire Arrays for Broad Spectrum Light Detection

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Solution Overview

Problem

Current nanotechnology in semiconductor devices faces challenges in efficiently absorbing or emitting light across a wide range of wavelengths due to limitations in nanowire bandgaps and material compatibility, which hinders the development of multi-color photodetectors and image sensors.

Innovation Solution

The use of multiple sets of nanowires with varying bandgaps, strategically layered and oriented, allows for the absorption or emission of different wavelengths, enabling the creation of multi-color photodetectors and image sensors by forming p-n or p-i-n junctions and utilizing catalyst nanoparticles for growth, with optional core/shell configurations for enhanced light collection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If single-material nanowires are used, then device structure is simple, but wavelength range is limited

Engineering Contradiction:

Improvewavelength rangeVSAvoiddevice structure

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The device is segmented into multiple nanowire sets, each with different bandgaps, arranged in series. Each nanowire set handles a specific wavelength range, allowing the overall device to detect or emit across a broad spectrum while maintaining manageable structural complexity through modular organization.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention uses composite material structures including core/shell nanowire configurations and heterostructure junctions. Different semiconductor materials with varying bandgaps are combined to create nanowires that can absorb or emit multiple wavelengths, effectively expanding the operational range without proportionally increasing device complexity.

Inventive Principle:

Principle #40Composite materials

2Adaptability or versatility

If multiple materials with different bandgaps are used, then wavelength coverage is improved, but lattice mismatch issues arise

Engineering Contradiction:

Improvewavelength coverageVSAvoidlattice mismatch

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The invention carefully selects semiconductor materials whose bandgap parameters progressively change across the desired wavelength range. By choosing materials with compatible lattice structures and gradually varying bandgaps, the device achieves broad wavelength coverage while minimizing lattice mismatch problems that would compromise reliability.

Inventive Principle:

Principle #35Parameter changes

3Productivity

If conventional semiconductor structures are used, then manufacturing is mature, but nanoscale light absorption efficiency is insufficient

Engineering Contradiction:

Improvelight absorption efficiencyVSAvoidnanoscale fabrication

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The invention transitions from planar semiconductor structures to vertically oriented nanowire structures. This dimensional change increases the surface area-to-volume ratio, enabling more efficient light absorption at the nanoscale. The vertical nanowire configuration allows mature semiconductor manufacturing techniques to be applied while achieving superior optical performance.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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

This approach enables the simultaneous detection and emission of multiple wavelengths, improving the sensitivity and efficiency of nanoscale devices like photodetectors and solar cells, while reducing manufacturing costs and avoiding lattice mismatch issues.

Implementation Method 1

each set may advantageously absorb/sense or emit light of a wavelength/range of wavelengths that is different from each other set

Methodology Applied

Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 2

multiple sets of nanowires, each of which has a bandgap that is the same as or different from a bandgap of each of the other sets

Methodology Applied

Scientific EffectBandgap energy transition: Photoelectric Effect

Data Source

PatentUS8030729B2Device for absorbing or emitting light and methods of making the same

Publication Date: 2011.10.04 HEWLETT PACKARD ENTERPRISE DEV LP

AI summary

A device disclosed herein includes a first layer, a second layer, and a first plurality of nanowires established between the first layer and the second layer. The first plurality of nanowires is formed of a first semiconductor material. The device further includes a third layer, and a second plurality of nanowires established between the second and third layers. The second plurality of nanowires is formed of a second semiconductor material having a bandgap that is the same as or different from a bandgap of the first semiconductor material.