Inorganic Luminescent Materials With Large Stokes Shift for Solar Conversion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current luminescent materials for solar radiation conversion devices, such as luminescent solar concentrators and conversion layers, face challenges including limited spectral absorption, self-absorption, and optical scattering, which hinder their efficiency and compatibility with photovoltaic devices and window applications.
Innovation Solution
Mn5+ doped inorganic luminescent materials and Sm2+ doped SiAlON materials are developed, which exhibit broad spectral absorption, large Stokes' shift to prevent self-absorption, and low optical scattering, enhancing the conversion efficiency and stability for use in solar radiation conversion devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional luminescent materials are used in solar radiation conversion devices, then the device can be manufactured with current technology, but the absorption efficiency and conversion efficiency are limited due to narrow spectral absorption and self-absorption issues
Solution Approach 1:
The patent applies parameter changes by selecting specific dopant ions (Mn5+, Sm2+, Tm2+) with optimized concentration ranges (0.01-10 mol%, 0.01-5 mol%, 0.01-1 mol% respectively) to achieve broad spectral absorption from UV to near-infrared regions. The host materials (Ba3(PO4)2, SiAlON) are selected and doped with precise compositions to maximize absorption efficiency while minimizing self-absorption, directly resolving the contradiction between conversion efficiency and absorption efficiency
Solution Approach 2:
The patent employs composite materials by combining specific host materials (Ba3(PO4)2, SiAlON) with rare-earth dopants (Mn5+, Sm2+, Tm2+). These composite luminescent materials exhibit synergistic properties where the host provides structural stability and the dopants provide broad spectral absorption with large Stokes shifts, thereby simultaneously improving both absorption efficiency and conversion efficiency without self-absorption losses
2Productivity
If luminescent materials with large Stokes' shift are used to prevent self-absorption, then the conversion efficiency improves, but the material stability and compatibility with standard manufacturing processes deteriorate
Solution Approach 1:
The patent applies inert atmosphere by synthesizing Tm2+ doped Ba3(PO4)2 materials in controlled inert environments to prevent oxidation of the divalent thulium ions. This inert environment processing ensures the maintenance of Tm2+ oxidation state which provides the desired large Stokes shift and broad absorption, while simultaneously ensuring material stability and compatibility with standard manufacturing processes
Solution Approach 2:
The patent uses composite materials where stable host structures (Ba3(PO4)2, SiAlON) encapsulate and protect the sensitive dopant ions (Tm2+, Mn5+, Sm2+). The host materials provide chemical stability and structural integrity, while the dopants provide the luminescent properties with large Stokes shifts, thus resolving the contradiction between conversion efficiency and material stability
3Productivity
If inorganic luminescent materials are used to reduce optical scattering and improve transparency, then the device performance improves, but the manufacturing complexity and process control difficulty increase
Solution Approach 1:
The patent applies parameter changes by optimizing the particle size distribution of the inorganic luminescent materials to specific ranges that minimize optical scattering. By controlling particle size parameters and doping concentrations during synthesis, the materials achieve high transparency and low haze while maintaining manufacturability through established ceramic and glass processing techniques
Solution Approach 2:
The patent employs cost-effective inorganic host materials (Ba3(PO4)2, SiAlON) that can be synthesized using relatively simple and scalable processes. These materials provide the desired optical properties with low scattering and high transparency without requiring complex manufacturing steps, thus improving device performance while controlling manufacturing complexity
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
These materials significantly improve the absorption and conversion efficiency of solar radiation, with Mn5+ materials showing high stability and compatibility for large-scale applications, and Sm2+ doped SiAlON materials providing low haze and high transparency, optimizing energy conversion in photovoltaic devices.
Implementation Method 1
Mn5+ doped inorganic luminescent materials and Sm2+ doped SiAlON materials are developed, which exhibit broad spectral absorption, large Stokes' shift to prevent self-absorption, and low optical scattering, enhancing the conversion efficiency and stability for use in solar radiation conversion devices
Implementation Method 2
Sm2+ doped SiAlON materials are developed, which exhibit broad spectral absorption, large Stokes' shift to prevent self-absorption, and low optical scattering, enhancing the conversion efficiency and stability for use in solar radiation conversion devices
Implementation Method 3
In such scheme sunlight is absorbed by the luminescent material in the plate and re-emitted in all directions. A considerable fraction of the light is trapped in the plate by total internal reflection. This way the plate acts as a light guide wherein the re-emitted light is guided to the perimeter of the plate where photovoltaic devices convert the light into electric power
Implementation Method 4
photovoltaic devices convert the light into electric power
Data Source
AI summary
A device for converting solar radiation is described wherein the device comprises an inorganic luminescent material comprising a host material doped with Mn5+ ions for converting radiation of the UV and/or visible part of the electromagnetic spectrum into radiation of the near-infrared radiation part of the electromagnetic spectrum, preferably the infrared part between 1150 nm and 1250 nm, preferably around 1190 nm (the infrared emission peak of Mn5+); or, an amorphous host material doped with Sm2+ or Tm2+ ions, the amorphous host material including the elements Al, Si, O and N (SiAlON) for converting radiation of the UV and/or visible part of the electromagnetic spectrum into radiation of a longer wavelength, preferably a longer wavelength between 650 nm and 800 nm or a longer wavelength of around 1140 nm; and, at least one photovoltaic device for converting at least part of the converted radiation into electrical power.