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Visible-to-UV Photon Upconversion in Nanostructured Chromophoric Ionic Liquids
Shota Hisamitsu1, Junji Miyano1, Keisuke Okumura1
1Department of Chemistry and Biochemistry, Graduate School of Engineering, Center for Molecular Systems (CMS), Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka, 819-0395, Japan.
Chemistryopen
|January 11, 2020
Summary
This study demonstrates visible-to-ultraviolet photon upconversion using triplet-triplet annihilation in a novel ionic liquid. Efficient energy transfer occurred due to chromophore self-assembly, enabling upconversion at low light intensities.
Area of Science:
- Materials Science
- Photochemistry
- Physical Chemistry
Background:
- Photon upconversion processes are crucial for various optical applications.
- Triplet-triplet annihilation-based photon upconversion (TTA-UC) offers efficient light conversion but often requires high excitation intensities.
- Developing new materials that facilitate TTA-UC under mild conditions is an active research area.
Purpose of the Study:
- To investigate visible-to-ultraviolet (vis-to-UV) TTA-UC in a chromophoric ionic liquid (IL).
- To explore the role of chromophore arrangement within the IL on TTA-UC efficiency.
- To achieve efficient TTA-UC at low excitation intensities.
Main Methods:
- Synthesis and characterization of a chromophoric ionic liquid.
- Investigation of chromophore self-assembly and nanodomain formation within the IL.
- Measurement of vis-to-UV TTA-UC performance under varying excitation intensities.
Main Results:
- Spontaneous formation of continuous chromophore arrays in non-polar nano-domains of the IL.
- Effective diffusion of triplet excitons facilitated by the ordered chromophore arrangement.
- Successful demonstration of vis-to-UV TTA-UC at low excitation intensity.
Conclusions:
- Chromophoric ionic liquids can effectively promote TTA-UC through self-assembly.
- Ordered chromophore arrays enhance triplet exciton diffusion, leading to efficient photon upconversion.
- This approach offers a promising pathway for low-intensity light-driven upconversion technologies.
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