Nicotinamide N-Doping for Stable Carbon Nanotube Electronics

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Solution Overview

Problem

Carbon nanotubes (CNTs) typically have a p-doping state after preparation, making it challenging to maintain a stable n-doping state, which is essential for various electronic devices, and existing n-doping agents may not provide long-term stability or easy control over the n-doping state, especially in air.

Innovation Solution

Nicotinamide and compounds chemically combined with nicotinamide are used as CNT n-doping materials, which can maintain a stable n-doping state for an extended period and allow for easy control by heating and adjusting the concentration, preventing de-doping even in air.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional n-doping agents (alkali metals, reducing polymers) are used on CNTs, then n-doping state is achieved, but the doping state is unstable and de-doping occurs over time or in air

Engineering Contradiction:

Improvestability of n-doping stateVSAvoidduration of n-doping state

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent changes the chemical parameters of the doping agent by using nicotinamide and its derivatives instead of conventional alkali metals or reducing polymers. These compounds provide stable electron donation to CNTs through their molecular structure, maintaining n-doping state without degradation over time or in air exposure.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs composite chemical structures where nicotinamide is combined with various functional groups or molecular frameworks to create stable doping agents. These composite molecular structures enhance both the stability and duration of the n-doping state while preventing de-doping reactions.

Inventive Principle:

Principle #40Composite materials

2Ease of operation

If oxidizing agents are used to control p-doping state of CNTs, then p-doping control is achieved, but the process requires multiple chemical treatment steps

Engineering Contradiction:

Improveease of controlling doping stateVSAvoidcomplexity of doping process

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

Instead of using oxidizing agents to control p-doping as in conventional methods, the patent inverts the approach by using stable n-doping agents that can be easily applied and maintained. This simplifies the overall doping control process while achieving reliable n-type characteristics in CNT-based devices.

Inventive Principle:

Principle #13The other way round (Inversion)

3Quantity of substance

If reducing agents like alkali metals are used for CNT n-doping, then electron donation is achieved, but the doping state is not stable in air and de-doping occurs

Engineering Contradiction:

Improveelectron donation to CNTsVSAvoidstability in air

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent replaces unstable alkali metal dopants with organic compounds like nicotinamide that, while providing similar electron donation capability, offer long-term stability in air. These molecular dopants act as stable, non-volatile sources of electrons that do not oxidize or degrade under ambient conditions.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

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 nicotinamide-based compounds enables stable n-doping of CNTs, maintaining n-type characteristics over time and allowing for controlled n-doping states in devices like CNT-FETs, p-n junction diodes, and CMOS, without the oxidation issues associated with metal compounds.

Implementation Method 1

reducing agents which can donate electrons to CNTs may be used. Examples of the reducing agents may include but are not limited to alkali metals including but not limited to potassium, sodium, etc., or reducing polymers including but not limited to polyethyleneimine (PEI), hydrazine, polyaniline, etc.

Methodology Applied

Scientific EffectElectron donation: Redox Reactions

Implementation Method 2

nicotinamide and/or a compound which is chemically combined with nicotinamide

Methodology Applied

Scientific EffectChemical bonding: Chemical Bonding

Data Source

PatentUS7968013B2Carbon nanotube N-doping material, carbon nanotube N-doping method and device using the same

Publication Date: 2011.06.28 SAMSUNG ELECTRONICS CO LTD

AI summary

Nicotinamide and/or a compound which is chemically combined with nicotinamide may be used as a carbon nanotube (“CNT”) n-doping material. CNTs n-doped with the CNT n-doping material may have long-lasting doping stability in the air without de-doping. Further, CNT n-doping state may be easily controlled when using the CNT n-doping material. The CNT n-doping material and/or CNTs n-doped with the CNT n-doping material may be used for various applications.