Europium-Activated Chlorosilicate Phosphor Composition for Green Light Emission
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Solution Overview
Problem
The existing green light emitting phosphors used in light emitting devices suffer from insufficient brightness and light loss due to the chlorosilicate composition, which results in reduced light emitting characteristics and the deterioration of semiconductor elements, particularly due to chlorine dissolution affecting the reflectivity and longevity of the device.
Innovation Solution
A phosphor composition with a specific element ratio of silicon, magnesium, and chlorine, activated with europium, where the molar ratio of chlorine to magnesium is within 1.0 ≤ Cl/Mg ≤ 1.9, and a formula representation that includes elements like Ca, Sr, Ba, Zn, and Mn, with halogen content controlled to minimize dissolution and enhance light emitting properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If chlorosilicate phosphor is used to achieve green light emission, then the phosphor can emit green light, but the brightness is insufficient and light loss increases
Solution Approach 1:
The patent changes the chemical composition parameters of the phosphor by controlling the molar ratio of chlorine to magnesium within 1.0 ≤ Cl/Mg ≤ 1.9, and adjusting the content of main body elements (Ca, Sr, Ba, Zn, or Mn) to 6.0-7.5 moles, Si to 4.0-5.0 moles, and Eu to 0.5-1.5 moles. This parameter optimization resolves the contradiction by achieving both sufficient brightness and reduced light loss simultaneously.
2Illumination intensity
If chlorosilicate phosphor is used, then green light emission is achieved, but chlorine dissolution deteriorates semiconductor elements
Solution Approach 1:
The patent optimizes the chlorine content by controlling the Cl/Mg molar ratio within 1.0-1.9 and the absolute chlorine content to 8.0 wt% or less. This parameter control reduces chlorine dissolution while maintaining green light emission properties, thereby protecting semiconductor elements from deterioration.
3Measurement precision
If the peak wavelength is at shorter wavelength side, then emission characteristics are achieved, but color filter transmissivity decreases
Solution Approach 1:
The patent adjusts the phosphor composition parameters, particularly the Cl/Mg ratio and europium content, to control the emission peak wavelength. By optimizing these parameters, the emission peak is positioned at an appropriate wavelength that achieves both precise wavelength control and sufficient color filter transmissivity, resolving the contradiction between wavelength positioning and light transmission.
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 proposed phosphor composition achieves high brightness and reduced light loss, maintaining the longevity of semiconductor elements by minimizing chlorine dissolution, thereby improving the overall light emitting characteristics and device performance.
Implementation Method 1
capable of absorbing near-ultraviolet light to blue light and emitting green light
Implementation Method 2
activated with europium
Data Source
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AI summary
Provided are a phosphor which is capable of emitting green light of high luminance and in which unfavorable effects on other members has been reduced so as to be applicable to white light having excellent light emitting characteristics, a light emitting device using the phosphor, and a method for manufacturing the phosphor. The phosphor containing silicon, magnesium, and chlorine, and activated with europium and capable of emitting green light, in which the molar ratio of chlorine to magnesium is in a range of 1.0 ≤ Cl/Mg ≤ 1.9. Introduction of chlorine at such a composition ratio improves the light emitting characteristics and the amount of chlorine dissolved.