Mn4+-Activated Fluoride Phosphor Durability via Controlled Doping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional Mn4+-activated red light-emitting fluoride fluorescent materials lack durability for harsh applications and suffer from reduced light extraction efficiency and internal fluorescence quantum efficiency when used in light-emitting devices with low correlated color temperature.
Innovation Solution
A method for producing Mn4+-activated red light-emitting fluoride fluorescent materials with a composition represented by A2[M1-aMn4+ aF6], involving the controlled dropwise addition of manganese and element solutions, followed by heating in an elemental fluorine atmosphere to achieve superior durability and high internal fluorescence quantum efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional Mn4+-activated fluoride fluorescent materials are used, then red light emission is achieved, but durability under harsh conditions deteriorates
Solution Approach 1:
The patent applies parameter changes by precisely controlling the Mn4+ concentration (0.01 ≤ a ≤ 0.20 in the formula A2[M1-aMn4+ aF6]) and using specific cations (K+, Na+, Li+, Cs+, Rb+) to optimize the crystal structure and electronic properties, thereby improving durability while maintaining red light emission
Solution Approach 2:
The patent uses composite materials by combining Mn4+ activated fluoride crystals with specific host lattices (MF6 where M represents various cations), creating a composite fluorescent material that exhibits both high durability and efficient red light emission under harsh conditions
2Illumination intensity
If conventional fluoride fluorescent materials are used in low CCT devices, then red light emission is achieved, but light extraction efficiency deteriorates
Solution Approach 1:
The patent optimizes the emission characteristics by controlling the Mn4+ concentration parameter (a) and selecting appropriate host cations, thereby tuning the emission spectrum to improve light extraction efficiency specifically in low CCT lighting applications
3Use of energy by moving object
If conventional fluoride fluorescent materials are used in low CCT devices, then red light emission is achieved, but internal fluorescence quantum efficiency deteriorates
Solution Approach 1:
The patent improves internal fluorescence quantum efficiency by precisely controlling the Mn4+ doping concentration (parameter a) and selecting optimal host cations, thereby reducing non-radiative recombination and enhancing radiative transitions specifically for low CCT device applications
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 method results in fluoride fluorescent materials with enhanced Mn4+ activation, improved durability, and high emission efficiency, suitable for use in light-emitting devices with reduced correlated color temperature, maintaining performance under harsh conditions.
Implementation Method 1
fluoride fluorescent materials having a composition, such as K2AlF5:Mn4+
Implementation Method 2
systems using a light emitting element that emits ultraviolet light and three types of fluorescent materials that emit red (R), green (G), and blue (B) light
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
A method for producing a fluoride fluorescent material including: preparing a first solution containing manganese, a second solution containing at least one cation selected from the group consisting of K+, Li+, Na+, Rb+, Cs+, and NH4+, and a third solution containing at least one element selected from the group consisting of the elements from Groups 4 and 14 of the periodic table, and adding the first and third solutions dropwise, each at a rate of 0.3 % or less of the total volume of the solution per minute to the second solution to obtain particles having a composition represented by formula (I): A2[M1-aMn4+aF6] (I) wherein A denotes at least one cation selected from the group consisting of K+, Li+, Na+, Rb+, Cs+, and NH4+; M denotes at least one element selected from the group consisting of the elements from Groups 4 and 14 of the periodic table; and a satisfies 0.04<a<0.20.