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TECHNIQUES FOR CONTROLLING PARTICLE SIZE DISTRIBUTION IN POTASSIUM FLUOROSILICATE PHOSPHORS (PFS)

IP.com Disclosure Number: IPCOM000241603D
Publication Date: 2015-May-15
Document File: 3 page(s) / 82K

Publishing Venue

The IP.com Prior Art Database

Abstract

The disclosure provides a technique for controlling the particle size distribution in the potassium fluorosilicate phosphors (PFS). An anti-solvent is added to a beaker having Hexafluorosilicic Acid (H2SiF6) and Hydrofluoric acid (HF). The anti-solvent is slowly added along with the Hexafluorosilicic acid (H2SiF6) to a solution bath containing KHF2 and K2MnF6. The particle size is controlled by controlling the quantity of anti-solvents in the reaction.

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TECHNIQUES FOR CONTROLLING PARTICLE SIZE DISTRIBUTION IN POTASSIUM FLUOROSILICATE PHOSPHORS (PFS)  

BACKGROUND

The present invention relates generally to display technologies and more particularly to a technique for controlling particle size distribution in potassium fluorosilicate phosphors.

Potassium Fluorosilicate (PFS) phosphors are widely used in LED-based display technologies. Generally, the PFS is synthesized by a solution route.  The solution route uses Potassium Bifluoride (KHF2), Hexafluorosilicic Acid (H2SiF6) and Potassium Hexafluoromanganate (K2MnF6) in Hydrofluoric acid (HF).  However, controlling particle size distribution and precipitation of PFS remains a challenge in the solution route.

It would be desirable to have a more efficient technique for synthesizing PFS. 

BRIEF DESCRIPTION OF DRAWINGS

Figure 1 is flow diagram depicting a technique to control particle size of the potassium fluorosilicate (PFS) phosphors.

DETAILED DESCRIPTION

The disclosure proposes a technique for synthesizing potassium fluorosilicate (PFS) phosphors.  The technique described herein enables control of particle size distribution of PFS. 

Generally, the PFS is synthesized by pumping solutions of Hexafluorosilicic Acid (H2SiF6) and Potassium Hexafluoromanganate (K2MnF6) in Hydrofluoric acid (HF) into a reaction bath containing KHF2 and K2MnF6.  The pumping is processed at a controlled rate.  This process results in precipitation of the PFS and generation of Manganese (Mn) particles of about 40 microns (d50) with Mn4+ distributed across the particle diameter. Figure 1 is flow diagram depicting the tec...