Coumarin Photon Upconversion Composition for Low-Intensity UV Conversion
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Solution Overview
Problem
Conventional photon upconversion compositions using heavy metals face environmental concerns and have limitations in conversion efficiency and excitation light intensity, while heavy metal-free compositions using biacetyl and 2,6-di-tert-butylnaphthalene require high excitation intensities for effective photon upconversion.
Innovation Solution
A photon upconversion composition utilizing a coumarin skeleton-based compound as a donor, which exhibits high upconversion efficiency at low excitation light intensity without heavy metals, incorporating a carbonyl group, halogen atoms, and potentially multiple coumarin skeletons for enhanced performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If heavy metal-based donor compounds (e.g., iridium complex) are used in photon upconversion composition, then the composition can achieve stable raw material supply and environmental compliance, but the visible light absorption by the donor is weak and the reabsorption of photon upconversion light is large, limiting the conversion efficiency
Solution Approach 1:
The invention changes the chemical composition parameters by replacing heavy metal-based donors with heavy metal-free organic donors (biacetyl, 4CzIPN, BCA). This parameter change resolves the contradiction by achieving both environmental compliance and improved photon upconversion efficiency through optimized molecular structures that reduce reabsorption losses.
Solution Approach 2:
The invention uses composite material design by combining specific donor compounds (biacetyl, 4CzIPN, or BCA) with acceptor compounds (DTB-NPh, TCTA, or mCP) in optimized ratios. This composite approach achieves high photon upconversion efficiency while maintaining environmental compliance through the synergistic interaction between carefully selected organic components.
2Object-affected harmful factors
If heavy metal-free donor compounds (e.g., biacetyl, 4CzIPN, BCA) are used in photon upconversion composition, then environmental concerns are eliminated, but the visible light absorption by the donor is weak and the threshold excitation intensity is high, resulting in low maximum UC efficiency
Solution Approach 1:
The invention optimizes molecular structure parameters by selecting and combining specific heavy metal-free donor compounds (biacetyl, 4CzIPN, BCA) with appropriate acceptor compounds. This parameter optimization achieves high photon upconversion efficiency while maintaining environmental compliance, resolving the contradiction between environmental safety and performance.
Solution Approach 2:
The invention employs composite material strategy by creating optimized combinations of heavy metal-free donor compounds with specific acceptor compounds (DTB-NPh, TCTA, mCP). These composite systems achieve superior photon upconversion efficiency compared to individual components, while maintaining environmental compliance through the synergistic effects of the organic compound combinations.
3Object-affected harmful factors
If conventional heavy metal-free donor compounds are used, then the composition avoids heavy metal toxicity, but the excitation light intensity threshold is extremely high (e.g., 1300 mW/cm2), making practical application difficult
Solution Approach 1:
The invention changes the optical parameters by optimizing the molecular structures and combinations of heavy metal-free donor and acceptor compounds. This optimization reduces the threshold excitation intensity from extremely high values (1300 mW/cm2) to practical levels, while maintaining non-toxicity and environmental compliance.
Solution Approach 2:
The invention uses composite material design by combining specific heavy metal-free donor compounds with optimized acceptor compounds in precise ratios. This composite approach reduces the excitation light intensity threshold to practical levels, making the system easy to operate while maintaining environmental safety through the use of non-toxic organic components.
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 composition achieves high upconversion efficiency with reduced excitation light intensity, overcoming the limitations of heavy metal-based and existing heavy metal-free compositions.
Implementation Method 1
when the donor is excited to an excited singlet state by irradiation with excitation light, and is then converted into an excited triplet state through intersystem crossing, and the triplet energy transfers to the acceptor. In the acceptor thus having been in an excited triplet state through energy acceptance, triplets between two molecules meet to cause triplet-triplet annihilation, and one molecule among them transitions into an excited singlet state having a higher energy than the excited triplet state to bring about light emission (photon upconversion emission)
Implementation Method 2
when the donor is excited to an excited singlet state by irradiation with excitation light, and is then converted into an excited triplet state through intersystem crossing
Implementation Method 3
the visible light absorption by the donor is weak, while the reabsorption of photon upconversion light (UC light) thereby is large
Data Source
AI summary
A photon upconversion composition containing a compound having a coumarin skeleton and not containing a heavy metal exhibits a high photon upconversion efficiency at a low excitation light intensity.