Continuous Graphene Deposition via Segmented Gas Injection
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Solution Overview
Problem
Existing methods for depositing large-area graphene layers require high temperatures and involve transferring processes, which lead to mechanical deformities, residual etchant issues, and defects in the graphene/substrate interface, degrading the material's properties.
Innovation Solution
A method and apparatus for continuous graphene deposition that forms a titanium layer on a substrate, reduces it using a reductant gas, and grows graphene using a reactant gas, all while moving in specific directions to prevent gas mixing, using a sputtering unit, reductant supply unit, reactant supply unit, purge supply unit, and exhaust units to maintain low temperatures below 300°C and avoid intermixing of gases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If high temperature deposition methods are used, then graphene layers can be formed, but the process requires high temperatures above 300°C which degrades material properties
Solution Approach 1:
The patent changes the deposition temperature parameter from conventional high temperatures (>300°C) to low temperatures (below 300°C) by using a dual-gas injection system with reductant gas (H2) and reactant gas (CH4), enabling graphene formation at temperatures that preserve substrate and material properties
2Area of stationary object
If transfer processes are used for graphene deposition, then large-area graphene can be formed, but mechanical deformities and defects occur at the graphene/substrate interface
Solution Approach 1:
The patent extracts and eliminates the transfer process from the graphene deposition methodology, enabling direct in-situ growth of large-area graphene layers on substrates without mechanical handling, thereby preventing interface defects and mechanical deformities
3Productivity
If reductant gas and reactant gas are supplied simultaneously, then deposition efficiency increases, but gas mixing occurs which degrades graphene quality
Solution Approach 1:
The patent segments the gas supply process into distinct temporal and spatial zones, injecting reductant gas and reactant gas at different times and locations through separate nozzles, preventing gas mixing while maintaining continuous deposition efficiency
Solution Approach 2:
The patent introduces a purge gas as an intermediary substance between the reductant gas and reactant gas zones, creating a physical barrier that prevents harmful gas mixing while allowing both gases to be supplied at high flow rates for efficient deposition
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
Enables the formation of high-quality, large-area graphene layers without the need for transfer processes, minimizing defects and maintaining the material's desirable properties, such as conductivity and transparency, by preventing gas mixing and using sequential and spatial separation of reductant and reactant gases.
Implementation Method 1
forming a titanium (Ti) layer on a substrate by sputtering
Implementation Method 2
reducing the titanium layer by spraying a reductant gas containing a hydrogen gas (H2)
Implementation Method 3
forming graphene by spraying a reactant gas containing a graphene source
Data Source
AI summary
A method for depositing a large-area graphene layer and an apparatus for continuous graphene deposition using the same are disclosed. The method can include forming a titanium (Ti) layer on a substrate by sputtering, reducing the titanium layer by spraying a reductant gas containing a hydrogen gas (H2) and a purge gas onto the titanium layer while moving in a first direction in relation to the substrate and exhausting the reductant gas and the purge gas. The method can also include forming graphene by spraying a reactant gas containing a graphene source and the purge gas onto the titanium layer while moving in a second direction opposite the first direction in relation to the substrate and exhausting the reactant gas and the purge gas.