Garnet Phosphor Composition for Narrowband Red Light
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional Eu3+-activated phosphors with a garnet structure do not emit red light with good color tone, making it difficult to provide light-emitting devices that emit a red light component with a good color tone.
Innovation Solution
A rare earth aluminum garnet-type inorganic oxide with a garnet structure, represented by the composition M2LnX2(AlO4)3, where M includes Ca, Ln includes Eu, and X includes Zr or Hf, emitting bright line-like fluorescent components within specific wavelength ranges, and a phosphor composed of this oxide that emits red light with narrowband characteristics and good color purity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional Eu3+-activated phosphors with garnet structure are used, then the phosphor can be manufactured with existing technology, but the emitted red light does not have good color tone
Solution Approach 1:
The invention changes the chemical composition parameters of the garnet structure by introducing specific rare earth elements (Ln) and metal elements (M) in controlled amounts, while maintaining the overall garnet crystal structure. This allows the material to retain manufacturability through existing synthesis methods while achieving improved red light emission with good color tone through compositional optimization.
Solution Approach 2:
The invention creates a composite phosphor material by combining Eu3+ activator with specific rare earth elements (Ln) and metal elements (M) within the garnet structure. This composite approach enables the material to exhibit both the structural stability needed for manufacturing and the enhanced optical properties required for good color tone red light emission.
2Illumination intensity
If the phosphor emits intense red light, then the brightness and visual sensitivity improve, but the bandwidth increases reducing color purity
Solution Approach 1:
The invention optimizes the concentration ratios of Eu3+ to other rare earth elements and metal elements to achieve a balance between emission intensity and spectral bandwidth. By precisely controlling these compositional parameters, the phosphor emits intense red light while maintaining narrow bandwidth and high color purity.
Solution Approach 2:
The invention creates localized optical environments around Eu3+ ions by introducing specific rare earth elements and metal elements at controlled positions within the garnet structure. This local modification of the crystal field enables enhanced red light emission intensity while maintaining the narrow spectral characteristics required for high color purity.
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 phosphor achieves intense red light emission with narrowband characteristics and good color purity, enabling light-emitting devices to produce red light with high visual sensitivity and brightness.
Implementation Method 1
Eu3+ in the inorganic oxide emits a plurality of bright line-like fluorescent components
Data Source
AI summary
An inorganic oxide has a composition represented by General formula: M2LnX2(AlO4)3 (where M includes Ca, Ln includes Eu, and X includes at least either one of Zr and Hf). Then, a crystal structure of the inorganic oxide is a garnet-type structure. Eu3+ in the inorganic oxide emits a plurality of bright line-like fluorescent components, and a principal bright line of the fluorescent component is present within a wavelength range of 600 nm or more to less than 628 nm. Moreover, a maximum height of the bright line present within a wavelength range of 700 nm or more to less than 720 nm is less than 60% of a maximum height of the principal bright line. A phosphor composed of the inorganic oxide can emit narrowband red light with good color purity.