Panchromatic Fluorescence Emission from Thienosquaraines Dyes: White Light Electrofluorochromic Devices

Electrofluorochromic devices (EFCDs) that allow the modulation of the light emitted by electroactive fluorophores are very attractive in the research field of optoelectronics. Here, the electrofluorochromic behaviour of a series of squaraine dyes was studied for the first time. In solutions, all com...

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Main Authors: Giuseppina Anna Corrente, Francesco Parisi, Vito Maltese, Sante Cospito, Daniela Imbardelli, Massimo La Deda, Amerigo Beneduci
Format: Article
Language:English
Published: MDPI AG 2021-11-01
Series:Molecules
Subjects:
Online Access:https://www.mdpi.com/1420-3049/26/22/6818
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author Giuseppina Anna Corrente
Francesco Parisi
Vito Maltese
Sante Cospito
Daniela Imbardelli
Massimo La Deda
Amerigo Beneduci
author_facet Giuseppina Anna Corrente
Francesco Parisi
Vito Maltese
Sante Cospito
Daniela Imbardelli
Massimo La Deda
Amerigo Beneduci
author_sort Giuseppina Anna Corrente
collection DOAJ
description Electrofluorochromic devices (EFCDs) that allow the modulation of the light emitted by electroactive fluorophores are very attractive in the research field of optoelectronics. Here, the electrofluorochromic behaviour of a series of squaraine dyes was studied for the first time. In solutions, all compounds are photoluminescent with maxima located in the range 665–690 nm, characterized by quantum yields ranging from 30% to 4.1%. Squaraines were incorporated in a polymer gel used as an active layer in all-in-one gel switchable EFCDs. An aggregation induced quenching occurs in the gel phase, causing a significant decrease in the emission quantum yield in the device. However, the squaraines containing the thieno groups (thienosquaraines, TSQs) show a panchromatic emission and their electrofluorochromism allows the tuning of the fluorescence intensity from 500 nm to the near infrared. Indeed, the application of a potential difference to the device induces a reversible quenching of their emission that is significantly higher and occurs at shorter switching times for TSQs-based devices compared to the reference squaraine dye (DIBSQ). Interestingly, the TSQs fluorescence spectral profile becomes more structured under voltage, and this could be explained by the shift of the aggregates/monomer equilibrium toward the monomeric species, due to electrochemical oxidation, which causes the disassembling of aggregates. This effect may be used to modulate the colour of the fluorescence light emitted by a device and paves the way for conceiving new electrofluorochromic materials based on this mechanism.
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spelling doaj.art-169827409a174343a21c30ecb77380862023-11-23T00:34:14ZengMDPI AGMolecules1420-30492021-11-012622681810.3390/molecules26226818Panchromatic Fluorescence Emission from Thienosquaraines Dyes: White Light Electrofluorochromic DevicesGiuseppina Anna Corrente0Francesco Parisi1Vito Maltese2Sante Cospito3Daniela Imbardelli4Massimo La Deda5Amerigo Beneduci6Laboratory of Physical Chemistry, Materials and Processes for Industry, Environment and Cultural Heritage, Department of Chemistry and Chemical Technologies, University of Calabria, Via P. Bucci, Cubo 15D, 87036 Arcavacata di Rende, ItalyLaboratory of Inorganic Molecular Materials, Department of Chemistry and Chemical Technologies, Institute of Nanotechnology CNR-Nanotec, University of Calabria, Via P. Bucci, Cubo 14C, 87036 Arcavacata di Rende, ItalyLaboratory of Physical Chemistry, Materials and Processes for Industry, Environment and Cultural Heritage, Department of Chemistry and Chemical Technologies, University of Calabria, Via P. Bucci, Cubo 15D, 87036 Arcavacata di Rende, ItalyLaboratory of Physical Chemistry, Materials and Processes for Industry, Environment and Cultural Heritage, Department of Chemistry and Chemical Technologies, University of Calabria, Via P. Bucci, Cubo 15D, 87036 Arcavacata di Rende, ItalyLaboratory of Physical Chemistry, Materials and Processes for Industry, Environment and Cultural Heritage, Department of Chemistry and Chemical Technologies, University of Calabria, Via P. Bucci, Cubo 15D, 87036 Arcavacata di Rende, ItalyLaboratory of Inorganic Molecular Materials, Department of Chemistry and Chemical Technologies, Institute of Nanotechnology CNR-Nanotec, University of Calabria, Via P. Bucci, Cubo 14C, 87036 Arcavacata di Rende, ItalyLaboratory of Physical Chemistry, Materials and Processes for Industry, Environment and Cultural Heritage, Department of Chemistry and Chemical Technologies, University of Calabria, Via P. Bucci, Cubo 15D, 87036 Arcavacata di Rende, ItalyElectrofluorochromic devices (EFCDs) that allow the modulation of the light emitted by electroactive fluorophores are very attractive in the research field of optoelectronics. Here, the electrofluorochromic behaviour of a series of squaraine dyes was studied for the first time. In solutions, all compounds are photoluminescent with maxima located in the range 665–690 nm, characterized by quantum yields ranging from 30% to 4.1%. Squaraines were incorporated in a polymer gel used as an active layer in all-in-one gel switchable EFCDs. An aggregation induced quenching occurs in the gel phase, causing a significant decrease in the emission quantum yield in the device. However, the squaraines containing the thieno groups (thienosquaraines, TSQs) show a panchromatic emission and their electrofluorochromism allows the tuning of the fluorescence intensity from 500 nm to the near infrared. Indeed, the application of a potential difference to the device induces a reversible quenching of their emission that is significantly higher and occurs at shorter switching times for TSQs-based devices compared to the reference squaraine dye (DIBSQ). Interestingly, the TSQs fluorescence spectral profile becomes more structured under voltage, and this could be explained by the shift of the aggregates/monomer equilibrium toward the monomeric species, due to electrochemical oxidation, which causes the disassembling of aggregates. This effect may be used to modulate the colour of the fluorescence light emitted by a device and paves the way for conceiving new electrofluorochromic materials based on this mechanism.https://www.mdpi.com/1420-3049/26/22/6818squarainesphotoluminescenceelectrofluorochromismelectrofluorochromic deviceelectrochemical properties
spellingShingle Giuseppina Anna Corrente
Francesco Parisi
Vito Maltese
Sante Cospito
Daniela Imbardelli
Massimo La Deda
Amerigo Beneduci
Panchromatic Fluorescence Emission from Thienosquaraines Dyes: White Light Electrofluorochromic Devices
Molecules
squaraines
photoluminescence
electrofluorochromism
electrofluorochromic device
electrochemical properties
title Panchromatic Fluorescence Emission from Thienosquaraines Dyes: White Light Electrofluorochromic Devices
title_full Panchromatic Fluorescence Emission from Thienosquaraines Dyes: White Light Electrofluorochromic Devices
title_fullStr Panchromatic Fluorescence Emission from Thienosquaraines Dyes: White Light Electrofluorochromic Devices
title_full_unstemmed Panchromatic Fluorescence Emission from Thienosquaraines Dyes: White Light Electrofluorochromic Devices
title_short Panchromatic Fluorescence Emission from Thienosquaraines Dyes: White Light Electrofluorochromic Devices
title_sort panchromatic fluorescence emission from thienosquaraines dyes white light electrofluorochromic devices
topic squaraines
photoluminescence
electrofluorochromism
electrofluorochromic device
electrochemical properties
url https://www.mdpi.com/1420-3049/26/22/6818
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AT vitomaltese panchromaticfluorescenceemissionfromthienosquarainesdyeswhitelightelectrofluorochromicdevices
AT santecospito panchromaticfluorescenceemissionfromthienosquarainesdyeswhitelightelectrofluorochromicdevices
AT danielaimbardelli panchromaticfluorescenceemissionfromthienosquarainesdyeswhitelightelectrofluorochromicdevices
AT massimoladeda panchromaticfluorescenceemissionfromthienosquarainesdyeswhitelightelectrofluorochromicdevices
AT amerigobeneduci panchromaticfluorescenceemissionfromthienosquarainesdyeswhitelightelectrofluorochromicdevices