CaCuSi4O10 Phosphor Broad Near-Infrared Emission
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Solution Overview
Problem
Conventional near-infrared phosphors with rare earth trivalent ions have sharp excitation and fluorescence spectra, limiting their use in a wide near-infrared region, and existing near-infrared LEDs require multiple LEDs of different wavelengths for sufficient coverage.
Innovation Solution
A phosphor oxide comprising Ca, Cu, and Si with specific molar ratios and a crystal phase of CaCuSi4O10, which can be excited by visible light to emit a broad near-infrared fluorescence spectrum with high intensity, suitable for various applications including spectrometers, OCT, solar power generators, and fluorescent paints.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If conventional near-infrared phosphors with rare earth trivalent ions are used, then high luminescent intensity is achieved, but the excitation and fluorescence spectra are sharp, limiting the coverage of the near-infrared region
Solution Approach 1:
The patent changes the chemical composition parameters by using divalent copper ions (Cu2+) instead of trivalent rare earth ions, and by adjusting the Ca/Si molar ratio to 0.15 or more. This parameter change transforms the emission characteristics from sharp peaks to a broad spectrum covering 800-1200 nm, while maintaining high luminescent intensity. The specific composition CaCuSi4O10 with controlled Ca/Si ratio is the key parameter change that resolves the contradiction.
2Illumination intensity
If conventional near-infrared phosphors with rare earth trivalent ions are used, then high luminescent intensity is achieved, but multiple phosphors or LEDs with different wavelengths are required for wide region coverage, increasing device complexity
Solution Approach 1:
The patent creates a universal phosphor material CaCuSi4O10 with Ca/Si≥0.15 that can cover the entire near-infrared region (800-1200 nm) with a single material. This multi-functional phosphor replaces the need for multiple specialized phosphors or LEDs, simplifying the device structure while maintaining high luminescent intensity across the broad spectrum.
3Adaptability or versatility
If a phosphor with broad fluorescence spectrum is used, then wide near-infrared region coverage is achieved, but luminescent intensity may be reduced
Solution Approach 1:
The patent optimizes the Ca/Si molar ratio parameter to 0.15 or more, which creates the optimal balance between broad spectrum coverage and high luminescent intensity. This specific parameter threshold ensures sufficient Ca2+ ions are available to generate strong luminescence while maintaining the broad emission spectrum characteristic of the CaCuSi4O10 crystal structure.
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 broad fluorescence emission with high intensity in the near-infrared range, enhancing its applicability in near-infrared spectrometers, OCT, solar power generation, and forgery-proof printing, while being excited by visible light across a wide band.
Implementation Method 1
a phosphor, which is excited by visible light, capable of emitting near-infrared light
Data Source
AI summary
Provided is a new phosphor which can be excited by visible light in a wide band to emit a broad fluorescence spectrum, and also to emit near-infrared light with high intensity. Proposed is a phosphor, which is an oxide comprising Ca, Cu, and Si, wherein the containing molar ratios of the elements are 0.15≤Ca/Si<0.25 and 0.13≤Cu/Si<0.25.