Mn-Free Fluoride Coating on Phosphor Core for Moisture Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Mn4+ activated fluoride phosphors are vulnerable to moisture and experience reduced durability and reliability under high temperature and high humidity conditions, affecting their performance in semiconductor light emitting devices.
Innovation Solution
A fluoride phosphor composite is developed with a Mn-free fluoride coating and an optional organic coating, where the fluoride phosphor core is coated with a Mn-free fluoride shell and/or an organic material to enhance optical properties and reliability, specifically designed for use in semiconductor light emitting devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If Mn4+ activated fluoride phosphor is used to achieve desired color characteristics, then color gamut is improved, but durability and reliability are degraded under high temperature and high humidity conditions
Solution Approach 1:
A Mn-free fluoride coating layer is introduced as an intermediary between the Mn4+ activated fluoride phosphor core and the external environment. This coating layer acts as a protective barrier that prevents moisture penetration while allowing optical excitation and emission to pass through, thus protecting the phosphor from degradation without affecting its color emission properties
Solution Approach 2:
The invention creates a composite structure consisting of a Mn4+ activated fluoride phosphor core coated with a Mn-free fluoride shell. This composite material combines the optical advantages of Mn4+ activated phosphor with the moisture resistance of Mn-free fluoride, achieving both high color gamut and improved reliability in harsh environments
2Illumination intensity
If Mn4+ activated fluoride phosphor is used to achieve desired color characteristics, then color gamut is improved, but reliability is degraded under high temperature conditions
Solution Approach 1:
The Mn-free fluoride coating serves as a thermal barrier and protective intermediary that shields the Mn4+ activated phosphor core from direct exposure to high temperature environments, preventing thermal degradation while maintaining optical performance
Solution Approach 2:
The composite structure of Mn4+ activated fluoride phosphor core with Mn-free fluoride coating provides both the color emission properties needed for high color gamut and thermal stability for improved reliability under high temperature conditions
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 fluoride phosphor composite exhibits improved external and internal quantum efficiencies, maintaining high performance even in harsh environments with enhanced durability and reliability, ensuring stable light emission under high temperature and high humidity conditions.
Implementation Method 1
A light emitting apparatus using such a semiconductor light emitting device may have a light emitting device providing excitation light and a phosphor excited by the light emitted from the light emitting device to emit wavelength-converted light
Data Source
AI summary
There is provided a fluoride phosphor composite including: fluoride phosphor core particles that may be expressed by the empirical formula AxMFy:Mn4+, wherein A may be at least one selected from the group consisting of Li, Na, K, Rb, and Cs, M may be at least one selected from the group consisting of Si, Ti, Zr, Hf, Ge, and Sn, the composition ratio (x) of A may satisfy 2≤x≤3, the composition ratio (y) of F may satisfy 4≤y≤7, each fluoride phosphor composite particle may be coated with a Mn-free fluoride coating. The Mn-free fluoride coating may have a thickness less than or equal to 35% of the size of each fluoride phosphor composite particle.