Luminescent Authenticity Marks via Host Lattice Tuning
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Solution Overview
Problem
The number of luminescent substances based on host lattices doped with ions suitable for securing documents of value is limited, particularly narrow-band luminescent substances have long lifespans and spectral positions of rare earth metal-based substances are difficult to influence, leading to inefficient excitation and limited differentiation.
Innovation Solution
Systematic changes in the host lattice and ions with (nd) 3< electron configuration allow targeted adjustment of luminescence properties, enabling the creation of complex new authenticity features through combinations of narrow-band and broadband luminescent substances with varied spectral positions and lifetimes, and introducing additional ions for energy transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If narrow-band luminescent substances based on transition metals are used, then reliable detection and differentiation are facilitated, but the luminescence lifespan becomes too long
Solution Approach 1:
The patent combines narrow-band luminescent substances (for detection precision) with broadband luminescent substances (for controlled lifespan) in composite authenticity features. This merging allows the document to exhibit multiple luminescence characteristics simultaneously, resolving the contradiction between long lifespan and reliable detection.
Solution Approach 2:
The invention uses composite luminescent materials consisting of multiple substances with different emission characteristics. By creating composite authenticity features that combine different luminescent substances, the patent achieves both precise spectral differentiation and controlled luminescence duration through the properties of individual components.
2Measurement precision
If rare earth metals are used as luminescent ions, then characteristic narrow-band luminescence is achieved, but the spectral position cannot be influenced much by the host lattice
Solution Approach 1:
The patent employs transition metal ions (with (nd)3 electron configuration) where the host lattice parameters (such as ligand field strength) can be systematically varied to adjust the luminescence spectral position. This parameter change approach allows fine-tuning of the emission wavelength while maintaining characteristic narrow-band structure, resolving the contradiction between spectral differentiation and adjustability.
3Measurement precision
If rare earth metals are used as luminescent ions, then narrow-band luminescence is achieved, but excitation efficiency becomes very low
Solution Approach 1:
The patent introduces broadband luminescent substances as intermediary components that can be efficiently excited and transfer energy to the narrow-band luminescent substances. This intermediary approach allows efficient excitation of the composite authenticity feature while maintaining the spectral differentiation capabilities of the narrow-band components.
4Adaptability or versatility
If the number of luminescent substances is increased to create diverse codings, then authentication capability is enhanced, but the complexity of the system increases
Solution Approach 1:
The patent segments the luminescent authenticity feature into distinct narrow-band and broadband substance components, each with specific functions. This segmentation allows systematic creation of multiple codings by combining different segments in controlled ways, enhancing authentication capability while maintaining manageable system complexity through modular design.
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
This approach significantly expands the range of luminescent substances with unique spectral properties, allowing for diverse codings, efficient excitation, and non-overlapping spectral ranges, enhancing document security by creating numerous distinct authenticity features.
Implementation Method 1
at least two luminescent substances based on host lattices that are doped with one or more ions... show one or more characteristic narrow-band luminescences
Implementation Method 2
in addition to the above-mentioned luminescence, so-called energy transfer processes can be observed, which can lead to more complicated spectra. In these energy transfer processes, an ion can transfer its energy to another ion
Data Source
Figure 1~2B
Figure 3~4B
Figure 5
AI summary
The invention relates to a printed valuable document comprising an authenticity mark in the form of at least two luminescent substances on the basis of host lattices that are doped with one or more ions. A targeted adjustment of the luminescent properties of luminescent substances can be achieved by the systematic modification of the host lattices and/or ions of the (nd)3 electron configuration. The combination of said luminescent substances permits a plurality of complex, novel authenticity marks.