Vanadium Disulfide Film CVD Process for Uniform Large-Area Deposition
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Solution Overview
Problem
Vanadium disulfide films obtained by conventional methods cannot be deposited conformally and uniformly on large surface substrates, limiting their application due to disjointed crystalline zones and incompatibility with large circular surfaces.
Innovation Solution
A chemical vapor deposition process in a vacuum reactor involving the injection of organometallic vanadium molecules, sulfur molecules with free thiol groups, and a reducing gas, ensuring uniform coverage and retention of high conductivity and work function properties, with optional repeated cycles and substrate heating to accelerate reactions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional solvothermal method or chemical deposition under vacuum is used to synthesize vanadium disulfide, then the material can be obtained with high conductivity and work function properties, but the deposit presents disjointed crystalline zones and cannot be deposited conformally and uniformly on large surface substrates
Solution Approach 1:
The patent changes the synthesis parameters by using organometallic vanadium precursors instead of traditional vanadium salts, controlling deposition temperature between 25-1000°C, and using specific sulfur sources with free thiol groups. These parameter changes enable conformal and uniform deposition on large surfaces while maintaining the desired electrical properties of vanadium disulfide
Solution Approach 2:
The patent employs a composite approach by combining organometallic vanadium compounds with organic sulfur sources containing free thiol groups. This composite material strategy allows for controlled chemical vapor deposition that produces uniform films with consistent crystalline structure across large substrate areas, resolving the issue of disjointed crystalline zones
2Manufacturing precision
If chemical vapor deposition is used to obtain uniform coverage, then the film can be deposited conformally on large surfaces, but the process requires vacuum conditions and multiple injection steps increasing process complexity
Solution Approach 1:
The patent applies preliminary action by pre-heating the substrate to the desired deposition temperature before introducing the organometallic vanadium precursor. This preliminary heating ensures the substrate is ready to immediately adsorb and react with the precursor, simplifying the overall process by eliminating the need for complex temperature cycling and reducing the number of process steps required
Solution Approach 2:
The patent uses organometallic compounds as intermediary species that facilitate the deposition process. These intermediaries decompose on the heated substrate surface to release vanadium atoms that react with sulfur, providing a controlled and simplified deposition mechanism that reduces process complexity compared to direct reaction methods
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 process enables the deposition of a transparent, conformal, and uniform vanadium disulfide film on substrates with large surface areas, maintaining high conductivity and work function properties, and is compatible with optical applications such as conductive electrodes.
Implementation Method 1
process for manufacturing a vanadium disulphide film by chemical vapor deposition on a previously heated substrate
Implementation Method 2
Injection of a reducing gas. Thanks to the invention, the organometallic molecule of vanadium binds to the substrate and then reacts with the sulfur molecule to form a film of vanadium disulphide
Implementation Method 3
The fact that the reactor is under vacuum makes it possible to avoid contamination of the sulfur molecule by the oxygen in the air
Implementation Method 4
chemical vapor deposition on a previously heated substrate
Data Source
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Figure 3~4
AI summary
One aspect of the invention relates to a process (100) for manufacturing a vanadium disulfide film (200) by chemical vapor deposition on a pre-heated substrate, comprising successive steps carried out in a vacuum reactor: i. Injection of at least one organometallic vanadium molecule, vanadium having a valence less than or equal to 4 (101); ii. Purging of the reactor (102); iii. Injection of at least one sulfur molecule comprising at least one free thiol group or forming a reaction intermediate comprising at least one free thiol group (103); iv. Injection of a reducing gas (104).