Ammonium Halide Phosphor Synthesis for Humidity Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The stability of phosphors used in white light-emitting devices is compromised due to the high absorbency of materials like SrCl2 and CaCl2, which require careful humidity control, making it challenging to maintain consistent properties during preparation.
Innovation Solution
A method for preparing a phosphor with a crystalline oxide framework containing a tetravalent metallic element, a halogen element, and divalent metal ions, using a compound like NH4X as a starting material, allowing for stable production across various environments without the need for specialized equipment to manage humidity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If SrCl2 or CaCl2 is used as a source of halogen element for phosphor preparation, then the phosphor can be synthesized with desired composition, but the material requires careful humidity control and specialized equipment to maintain stable properties
Solution Approach 1:
The patent changes the chemical form of the halogen source from hygroscopic metal halides (SrCl2, CaCl2) to non-hygroscopic ammonium halides (NH4X). This parameter change in the starting material's chemical composition eliminates the need for humidity control equipment while maintaining phosphor composition stability.
Solution Approach 2:
The patent replaces expensive and equipment-intensive metal halide sources with simpler, cheaper ammonium halide sources that can be handled in ordinary atmosphere without specialized humidity control equipment, effectively substituting a complex system with a simpler one.
2Quantity of substance
If SrCl2 or CaCl2 is used as starting material, then the phosphor can be prepared with required halogen content, but the amount of moisture content changes greatly depending on humidity requiring careful attention
Solution Approach 1:
The patent changes the physical and chemical parameters of the halogen source material from hygroscopic metal halides to non-hygroscopic ammonium halides. This parameter change ensures that the halogen content can be accurately controlled without the moisture content fluctuating with environmental humidity, achieving both goals simultaneously.
3Ease of manufacture
If metal halides like SrCl2 or CaCl2 are mixed with other raw materials in the atmosphere, then the phosphor can be prepared through conventional mixing, but the composition stability cannot be maintained due to moisture absorption
Solution Approach 1:
The patent modifies the chemical parameters of the halogen source from hygroscopic metal halides to non-hygroscopic ammonium halides, enabling conventional atmospheric mixing procedures to produce phosphors with consistent composition, thereby achieving both ease of manufacture and manufacturing precision.
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 phosphors with stable properties and high emission intensity, simplifying the preparation process and reducing the complexity of equipment requirements, while maintaining efficient excitation and emission performance.
Implementation Method 1
a phosphor that is efficiently excited by ultraviolet rays or in a short-wavelength region to emit light
Data Source
AI summary
A method for preparing a phosphor that comprises a crystalline oxide having M1O3 (M1 is a tetravalent metallic element) as a main framework thereof and essentially including a halogen element X (X is at least one element selected from a group consisting of F, Cl, Br, and I) and divalent metal ions M2 and Eu2+, includes using a compound represented by a compositional formula NH4X as a starting material when synthesizing the phosphor. At least a compound represented by a compositional formula NH4Cl may be used as the starting material.