Oxynitride Phosphor Composition for High-Temperature LED Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional fluorescent substances used in LEDs suffer from reduced emission intensity due to temperature quenching, especially at high operating temperatures, which affects their efficiency and color rendition, particularly in high-load applications.
Innovation Solution
A process for producing a red fluorescent substance with improved temperature characteristics, involving a mixture of specific metal elements and an emission center element, forming an oxynitride phosphor with a crystal structure that emits luminescence in the 570-650 nm range, which is less affected by heat, using compounds like Sr3N2, AlN, Si3N4, and EuN, and firing them under controlled conditions to create a stable and efficient light-emitting material.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If conventional fluorescent substances are used in high-load LEDs, then the LEDs can operate at high power, but the emission intensity is reduced due to temperature quenching
Solution Approach 1:
The patent changes the chemical composition parameters of the fluorescent substance by incorporating specific metal elements (M1: tetravalent, M2: trivalent, L: In(III) or Ga(III)) in controlled ratios. This compositional parameter change creates a crystal structure that is inherently more resistant to temperature quenching, allowing the material to maintain emission intensity at high operating temperatures while supporting high LED power levels
Solution Approach 2:
The patent creates a composite fluorescent material by combining multiple metal elements (M1, M2, L, M) with an emission center element EC in a specific compositional framework. This composite structure leverages the synergistic effects of different elements to achieve both high temperature stability and maintained emission intensity, resolving the contradiction between high power operation and emission performance
2Temperature
If conventional fluorescent substances are heated to 100-200°C, then the LEDs can dissipate heat, but the emission intensity is lowered
Solution Approach 1:
The patent modifies the thermal parameters of the fluorescent substance through compositional changes, specifically incorporating metal elements L (In(III) or Ga(III)) in controlled amounts (0.01-5 mol%). This changes the material's thermal response characteristics, creating a composition that maintains stable emission intensity across the 100-200°C operating temperature range typical of high-load LEDs
Solution Approach 2:
The patent introduces localized structural features within the fluorescent material by incorporating specific metal elements at controlled concentrations. The element L acts as a local structural modifier that creates regions of enhanced thermal stability within the crystal lattice, allowing the material to locally resist temperature-induced emission degradation while maintaining overall structural integrity
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 resulting fluorescent substance maintains high emission intensity and improved chromaticity even at elevated temperatures, enhancing the efficiency and color rendition of LEDs, suitable for high-load applications and broadening the color gamut.
Implementation Method 1
a fluorescent substance which emits luminescence having a peak in a wavelength range of 570 to 650 nm under excitation by light in a wavelength range of 250 to 500 nm
Data Source
AI summary
The embodiment provides a process for production of an oxynitride fluorescent substance. An compound containing In or Ga is adopted in the process as a material thereof. The red fluorescent substance produced by the process can be combined with a semiconductor light-emitting element, so as to be used in a light-emitting device or a light-emitting module.