Zinc Oxysulphide CVD Coating Preventing Apparatus Blockage
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Solution Overview
Problem
Existing methods for depositing zinc oxysulphide coatings using dialkyl zinc precursors face challenges with pre-reaction issues, leading to blockage of CVD apparatus and exhaust systems, especially at high substrate temperatures, making it difficult to operate in float glass manufacturing environments.
Innovation Solution
A method involving Atmospheric Pressure Chemical Vapour Deposition using a mixture of dimethyl zinc or diethyl zinc as the zinc source, an episulphide or sulphoxide as the sulphur source, and nitrous oxide or carboxylic esters as the oxygen source, allowing for pre-mixing of precursors without pre-reaction, and controlling the oxygen/sulphur content in the coatings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If dialkyl zinc precursors are used for depositing zinc oxysulphide coatings, then coating deposition is achieved, but pre-reaction occurs leading to blockage of CVD apparatus and exhaust systems
Solution Approach 1:
The precursor delivery system is segmented into separate channels: one for dialkyl zinc and another for sulphur-containing precursor. This physical separation prevents pre-reaction in the mixing zone while allowing controlled reaction at the substrate surface, resolving the contradiction between achieving coating deposition and preventing apparatus blockage
Solution Approach 2:
A carrier gas (nitrogen or argon) acts as an intermediary medium to transport the dialkyl zinc and sulphur precursors separately through the CVD chamber. The carrier gas enables precursor delivery without direct contact between precursors until they reach the heated substrate, preventing premature reaction while ensuring coating formation
2Reliability
If complex delivery systems with separate precursor lines are used, then pre-reaction is prevented, but device complexity increases
Solution Approach 1:
Multiple precursor delivery functions are merged into a single CVD chamber environment where separate precursor inlets feed into a common reaction zone. The chamber's heated atmosphere and flow dynamics naturally separate and control the precursors until they reach the substrate, reducing external complexity while maintaining pre-reaction prevention
Solution Approach 2:
The CVD chamber serves multiple functions: it acts as the reaction vessel, the heating zone, the precursor mixing chamber (with controlled separation), and the deposition surface. This multi-functionality eliminates the need for separate dedicated delivery systems for each precursor, simplifying the overall apparatus while preventing pre-reaction
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 production of stable and efficient zinc oxysulphide coatings on glass substrates, reducing the need for complex delivery systems and preventing apparatus blockage, while maintaining coating quality and substrate integrity.
Implementation Method 1
The invention relates to a method of forming a coating comprising ZnO (1-x) S x by Atmospheric Pressure Chemical Vapour Deposition
Implementation Method 2
The glass substrate is heated to a temperature sufficient to cause the reaction
Data Source
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AI summary
A method of coating a substrate with zinc oxysulphate (ZnO(1-x)Sx, where 0 ≤ x ≤ 1) by atmospheric pressure chemical vapour deposition is disclosed. Various precursors offering sources of zinc, oxygen and sulphur are provided.