Effect of the Mixture Composition of BmimBF4–Acetonitrile on the Excited-State Relaxation Dynamics of a Solar-Cell Dye D149: An Ultrafast Transient Absorption Study

2021 ◽  
Author(s):  
Nishith Maity ◽  
Piotr Piatkowski ◽  
Kamil Polok ◽  
François-Alexandre Miannay ◽  
Abdenacer Idrissi
Keyword(s):  
Excited State ◽  
Solar Cell ◽  
Transient Absorption ◽  
Mixture Composition ◽  
Absorption Study ◽  
Relaxation Dynamics ◽  
Ultrafast Transient Absorption

The Effect of the Mixture Composition of BmimBF4-Acetonitrile on the Excited State Relaxation Dynamics of a Solar Cell Dye D149: An Ultrafast Transient Absorption Study

2021 ◽  
Author(s):  
Nishith Maity ◽  
Piotr Piatkowski ◽  
Kamil Polok ◽  
Francois-Alexandre Miannay ◽  
Abdenacer Idrissi
Keyword(s):  
Ionic Liquid ◽  
Excited State ◽  
Solar Cell ◽  
Transient Absorption ◽  
Excited Electronic State ◽  
Relaxation Times ◽  
High Viscosity ◽  
Mixture Composition ◽  
Gradual Change ◽  
The One

It has been recognized that the understanding of the photo physic of the dyes used in solar cells in an important step in improving their efficiency. Certainly using ionic liquid as an electrolyte is a good solution as it stabilizes the excited state of the dye, however, because of the high viscosity, the diffusion of the components of the solar cell (dye, electrolyte, the chosen redox couple) is very low and has consequences on the other processes (Forward and backward processes). One of the ideas, is to modulate the viscosity of the ionic liquid by mixing the ionic liquid with a solvent. The goal then of this work is to quantify the mixture composition dependence of the excited state relaxation times. Other studies should be carried out to quantify the mixture dependence on the time characteristics of other processes (charge injection, collection etc.) to optimize the working optimal conditions of the solar cell. Following this goal, the present study is devoted to characterize the relaxation time of in the whole mixture composition of BmimBF4 and acetonitrile and in the neat components. For the first time, the decay relaxation times of the first excited electronic state of D149 dye, as obtained by transient absorption spectroscopy (TAS). These relaxation times are monitored by a gradual change of the local structure around a dye, from the one dominated by the interionic interactions, high viscosity and low polarity (as quantified by the static dielectric constant) in BmimBF4 to the one that is dominated by dipole-dipole interactions, low viscosity and high polarity in acetonitrile.<br>

scholarly journals The Effect of the Mixture Composition of BmimBF4-Acetonitrile on the Excited State Relaxation Dynamics of a Solar Cell Dye D149: An Ultrafast Transient Absorption Study

2021 ◽  
Author(s):  
Nishith Maity ◽  
Piotr Piatkowski ◽  
Kamil Polok ◽  
Francois-Alexandre Miannay ◽  
Abdenacer Idrissi
Keyword(s):  
Ionic Liquid ◽  
Excited State ◽  
Solar Cell ◽  
Transient Absorption ◽  
Excited Electronic State ◽  
Relaxation Times ◽  
High Viscosity ◽  
Mixture Composition ◽  
Gradual Change ◽  
The One

It has been recognized that the understanding of the photo physic of the dyes used in solar cells in an important step in improving their efficiency. Certainly using ionic liquid as an electrolyte is a good solution as it stabilizes the excited state of the dye, however, because of the high viscosity, the diffusion of the components of the solar cell (dye, electrolyte, the chosen redox couple) is very low and has consequences on the other processes (Forward and backward processes). One of the ideas, is to modulate the viscosity of the ionic liquid by mixing the ionic liquid with a solvent. The goal then of this work is to quantify the mixture composition dependence of the excited state relaxation times. Other studies should be carried out to quantify the mixture dependence on the time characteristics of other processes (charge injection, collection etc.) to optimize the working optimal conditions of the solar cell. Following this goal, the present study is devoted to characterize the relaxation time of in the whole mixture composition of BmimBF4 and acetonitrile and in the neat components. For the first time, the decay relaxation times of the first excited electronic state of D149 dye, as obtained by transient absorption spectroscopy (TAS). These relaxation times are monitored by a gradual change of the local structure around a dye, from the one dominated by the interionic interactions, high viscosity and low polarity (as quantified by the static dielectric constant) in BmimBF4 to the one that is dominated by dipole-dipole interactions, low viscosity and high polarity in acetonitrile.<br>

The Effect of the Mixture Composition of BmimBF4-Acetonitrile on the Excited State Relaxation Dynamics of a Solar Cell Dye D149: An Ultrafast Transient Absorption Study

2021 ◽  
Author(s):  
Nishith Maity ◽  
Piotr Piatkowski ◽  
Kamil Polok ◽  
Francois-Alexandre Miannay ◽  
Abdenacer Idrissi
Keyword(s):  
Ionic Liquid ◽  
Excited State ◽  
Solar Cell ◽  
Transient Absorption ◽  
Excited Electronic State ◽  
Relaxation Times ◽  
High Viscosity ◽  
Mixture Composition ◽  
Gradual Change ◽  
The One

It has been recognized that the understanding of the photo physic of the dyes used in solar cells in an important step in improving their efficiency. Certainly using ionic liquid as an electrolyte is a good solution as it stabilizes the excited state of the dye, however, because of the high viscosity, the diffusion of the components of the solar cell (dye, electrolyte, the chosen redox couple) is very low and has consequences on the other processes (Forward and backward processes). One of the ideas, is to modulate the viscosity of the ionic liquid by mixing the ionic liquid with a solvent. The goal then of this work is to quantify the mixture composition dependence of the excited state relaxation times. Other studies should be carried out to quantify the mixture dependence on the time characteristics of other processes (charge injection, collection etc.) to optimize the working optimal conditions of the solar cell. Following this goal, the present study is devoted to characterize the relaxation time of in the whole mixture composition of BmimBF4 and acetonitrile and in the neat components. For the first time, the decay relaxation times of the first excited electronic state of D149 dye, as obtained by transient absorption spectroscopy (TAS). These relaxation times are monitored by a gradual change of the local structure around a dye, from the one dominated by the interionic interactions, high viscosity and low polarity (as quantified by the static dielectric constant) in BmimBF4 to the one that is dominated by dipole-dipole interactions, low viscosity and high polarity in acetonitrile.<br>

Excited state relaxation paths in 9,9′-bianthryl and 9-carbazolyl-anthracene: a sub-ps transient absorption study

2000 ◽  
Vol 253 (2-3) ◽  
pp. 339-349 ◽  
Author(s):  
Martin Jurczok ◽  
Pascal Plaza ◽  
Monique M Martin ◽  
Yves H Meyer ◽  
Wolfgang Rettig
Keyword(s):  
Excited State ◽  
Transient Absorption ◽  
Absorption Study

scholarly journals Tunable Non-linear Refraction Properties and Ultrafast Excited State Dynamics of Dicyanomethylene Dihydrofuran Derivative

2020 ◽  
Vol 8 ◽  
Author(s):  
Linpo Yang ◽  
Zhongguo Li ◽  
Taihui Wei ◽  
Liming Zhou ◽  
Feng Li ◽  
...  
Keyword(s):  
Excited State ◽  
Transient Absorption ◽  
Refraction Index ◽  
Fast Response ◽  
Transient Absorption Spectroscopy ◽  
Relaxation Dynamics ◽  
Substantial Impact ◽  
Femtosecond Transient Absorption ◽  
Non Linear ◽  
Linear Optical

The third order non-linear optical response of a dicyanomethylene dihydrofuran compound (DCDHF-2V) was investigated using a Z-scan technique in picosecond and nanosecond time regimes. The results show that DCDHF-2V has excellent excited state non-linear refraction properties on both time regimes, and the non-linear refraction index is also solvent-dependent in the nanosecond regime. The excited state relaxation dynamics of DCDHF-2V were demystified via femtosecond transient absorption spectroscopy. The TA spectra reveal that the solvent viscosities have a substantial impact on the excited state relaxation of DCDHF-2V. The exotic photophysical phenomena in DCDHF-2V reported herein can shed new light on future development of small organic non-linear optical materials with large non-linear coefficients and fast response.

scholarly journals Photoexcitation of Ge9− Clusters in THF: New Insights into the Ultrafast Relaxation Dynamics and the Influence of the Cation

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2639
Author(s):  
Nadine C. Michenfelder ◽  
Christian Gienger ◽  
Melina Dilanas ◽  
Andreas Schnepf ◽  
Andreas-Neil Unterreiner
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Conduction Band ◽  
Near Infrared ◽  
Transient Absorption ◽  
Time Window ◽  
Excess Electron ◽  
Cluster Core ◽  
Relaxation Dynamics ◽  
Additional Time

We present a comprehensive femtosecond (fs) transient absorption study of the [Ge9(Hyp)3]− (Hyp = Si(SiMe3)3) cluster solvated in tetrahydrofuran (THF) with special emphasis on intra- and intermolecular charge transfer mechanisms which can be tuned by exchange of the counterion and by dimerization of the cluster. The examination of the visible and the near infrared (NIR) spectral range reveals four different processes of cluster dynamics after UV (267/258 nm) photoexcitation related to charge transfer to solvent and localized excited states in the cluster. The resulting transient absorption is mainly observed in the NIR region. In the UV-Vis range transient absorption of the (neutral) cluster core with similar dynamics can be observed. By transferring concepts of: (i) charge transfer to the solvent known from solvated Na− in THF and (ii) charge transfer in bulk-like materials on metalloid cluster systems containing [Ge9(Hyp)3]− moieties, we can nicely interpret the experimental findings for the different compounds. The first process occurs on a fs timescale and is attributed to localization of the excited electron in the quasi-conduction band/excited state which competes with a charge transfer to the solvent. The latter leads to an excess electron initially located in the vicinity of the parent cluster within the same solvent shell. In a second step, it can recombine with the cluster core with time constants in the picosecond (ps) timescale. Some electrons can escape the influence of the cluster leading to a solvated electron or after interaction with a cation to a contact pair both with lifetimes exceeding our experimentally accessible time window of 1 nanosecond (ns). An additional time constant on a tens of ps timescale is pronounced in the UV-Vis range which can be attributed to the recombination rate of the excited state or quasi conduction band of Ge9−. In the dimer, the excess electron cannot escape the molecule due to strong trapping by the Zn cation that links the two cluster cores.

Excited-state dynamics of heteroleptic copper(i) photosensitizers and their electrochemically reduced forms containing a dipyridophenazine moiety – a spectroelectrochemical transient absorption study

2019 ◽  
Vol 21 (20) ◽  
pp. 10716-10725
Author(s):  
Ying Zhang ◽  
Linda Zedler ◽  
Michael Karnahl ◽  
Benjamin Dietzek
Keyword(s):  
Excited State ◽  
Transient Absorption ◽  
Absorption Study ◽  
Excited State Dynamics ◽  
Reduced Forms

Heteroleptic copper(i) dipyridophenazine complexes were investigated by transient absorption spectroelectrochemistry to examine their multi-electron photoaccumulation properties.

Sign in / Sign up

Export Citation Format

Share Document