Exited by Light: Computational Investigations of Chromophores, Dyads and Triads

Freja Eilsø Storm

Exited by Light: Computational Investigations of Chromophores, Dyads and Triads

Freja Eilsø Storm

Abstract

The world population is increasing, and with that, the demand for energy is rising as well. To meet this demand, while still maintaining a stable environment, alternative strategies for energy production are needed. In this thesis, a number of computational investigations on chromophores, molecular triads and dyads are presented since these systems might prove to be important building blocks for these new strategies, as they are related to the construction of more efficient Organic Photo Voltaics (OPV) devices. First, Density Functional Theory (DFT) investigations of chromophores based on Boron- Subphthalocyanine (SubPc) are presented, and a number of possible routes for modification/functionalization of the SubPc core structure are presented, along with the consequences of these modifications for solar cell application. By functionalization or core-extension, the absorption properties, and Molecular Orbital (MO) energies of the frontier MOs of SubPc can be finely tuned. Secondly, I present a complete framework to transform standard DFT calculations on single molecules, into Redfield based simulation of the Electron Transfer (ET) and Hole Transfer (HT) properties of molecular triads or dyads. From DFT, a method for building a system Hamiltonian, including diabatic state energies and electronic couplings, as well as an intramolecular normal-mode based correlation function is presented. Redfield theory dynamics based on these system Hamiltonians and normal-mode correlation functions are able to reproduce experimental findings of a 1,3-bis(3-perylenyl)propane(Pe-Pr-Pe) dyad. Finally, I present how Machine Learning (ML) can be applied to predict the energies of the frontier orbitals of SubPc based triads functionalized in the periphery with selected ligands. With ML a database of 12.000 structures, with DFT calculated MO energies, can be used to predict the Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) energies of more than 40.000 SubPc triads. Combining these three parts could potentially lead to an efficient screening tool where the best among thousands of potential OPV candidate triads or dyads could be predicted, at a relatively low computational cost. In this way, the improvement of OPV efficiencies could be significantly aided, saving many hours of expensive trial-and-error synthesis work.

Originalsprog	Engelsk

Forlag	Department of Chemistry, Faculty of Science, University of Copenhagen
Status	Udgivet - 2019

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Citationsformater

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title = "Exited by Light: Computational Investigations of Chromophores, Dyads and Triads",

abstract = "The world population is increasing, and with that, the demand for energy is rising as well. To meet this demand, while still maintaining a stable environment, alternative strategies for energy production are needed. In this thesis, a number of computational investigations on chromophores, molecular triads and dyads are presented since these systems might prove to be important building blocks for these new strategies, as they are related to the construction of more efficient Organic Photo Voltaics (OPV) devices. First, Density Functional Theory (DFT) investigations of chromophores based on Boron- Subphthalocyanine (SubPc) are presented, and a number of possible routes for modification/functionalization of the SubPc core structure are presented, along with the consequences of these modifications for solar cell application. By functionalization or core-extension, the absorption properties, and Molecular Orbital (MO) energies of the frontier MOs of SubPc can be finely tuned. Secondly, I present a complete framework to transform standard DFT calculations on single molecules, into Redfield based simulation of the Electron Transfer (ET) and Hole Transfer (HT) properties of molecular triads or dyads. From DFT, a method for building a system Hamiltonian, including diabatic state energies and electronic couplings, as well as an intramolecular normal-mode based correlation function is presented. Redfield theory dynamics based on these system Hamiltonians and normal-mode correlation functions are able to reproduce experimental findings of a 1,3-bis(3-perylenyl)propane(Pe-Pr-Pe) dyad. Finally, I present how Machine Learning (ML) can be applied to predict the energies of the frontier orbitals of SubPc based triads functionalized in the periphery with selected ligands. With ML a database of 12.000 structures, with DFT calculated MO energies, can be used to predict the Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) energies of more than 40.000 SubPc triads. Combining these three parts could potentially lead to an efficient screening tool where the best among thousands of potential OPV candidate triads or dyads could be predicted, at a relatively low computational cost. In this way, the improvement of OPV efficiencies could be significantly aided, saving many hours of expensive trial-and-error synthesis work. ",

author = "Storm, {Freja Eils{\o}}",

year = "2019",

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publisher = "Department of Chemistry, Faculty of Science, University of Copenhagen",

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TY - BOOK

T1 - Exited by Light

T2 - Computational Investigations of Chromophores, Dyads and Triads

AU - Storm, Freja Eilsø

PY - 2019

Y1 - 2019

N2 - The world population is increasing, and with that, the demand for energy is rising as well. To meet this demand, while still maintaining a stable environment, alternative strategies for energy production are needed. In this thesis, a number of computational investigations on chromophores, molecular triads and dyads are presented since these systems might prove to be important building blocks for these new strategies, as they are related to the construction of more efficient Organic Photo Voltaics (OPV) devices. First, Density Functional Theory (DFT) investigations of chromophores based on Boron- Subphthalocyanine (SubPc) are presented, and a number of possible routes for modification/functionalization of the SubPc core structure are presented, along with the consequences of these modifications for solar cell application. By functionalization or core-extension, the absorption properties, and Molecular Orbital (MO) energies of the frontier MOs of SubPc can be finely tuned. Secondly, I present a complete framework to transform standard DFT calculations on single molecules, into Redfield based simulation of the Electron Transfer (ET) and Hole Transfer (HT) properties of molecular triads or dyads. From DFT, a method for building a system Hamiltonian, including diabatic state energies and electronic couplings, as well as an intramolecular normal-mode based correlation function is presented. Redfield theory dynamics based on these system Hamiltonians and normal-mode correlation functions are able to reproduce experimental findings of a 1,3-bis(3-perylenyl)propane(Pe-Pr-Pe) dyad. Finally, I present how Machine Learning (ML) can be applied to predict the energies of the frontier orbitals of SubPc based triads functionalized in the periphery with selected ligands. With ML a database of 12.000 structures, with DFT calculated MO energies, can be used to predict the Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) energies of more than 40.000 SubPc triads. Combining these three parts could potentially lead to an efficient screening tool where the best among thousands of potential OPV candidate triads or dyads could be predicted, at a relatively low computational cost. In this way, the improvement of OPV efficiencies could be significantly aided, saving many hours of expensive trial-and-error synthesis work.

AB - The world population is increasing, and with that, the demand for energy is rising as well. To meet this demand, while still maintaining a stable environment, alternative strategies for energy production are needed. In this thesis, a number of computational investigations on chromophores, molecular triads and dyads are presented since these systems might prove to be important building blocks for these new strategies, as they are related to the construction of more efficient Organic Photo Voltaics (OPV) devices. First, Density Functional Theory (DFT) investigations of chromophores based on Boron- Subphthalocyanine (SubPc) are presented, and a number of possible routes for modification/functionalization of the SubPc core structure are presented, along with the consequences of these modifications for solar cell application. By functionalization or core-extension, the absorption properties, and Molecular Orbital (MO) energies of the frontier MOs of SubPc can be finely tuned. Secondly, I present a complete framework to transform standard DFT calculations on single molecules, into Redfield based simulation of the Electron Transfer (ET) and Hole Transfer (HT) properties of molecular triads or dyads. From DFT, a method for building a system Hamiltonian, including diabatic state energies and electronic couplings, as well as an intramolecular normal-mode based correlation function is presented. Redfield theory dynamics based on these system Hamiltonians and normal-mode correlation functions are able to reproduce experimental findings of a 1,3-bis(3-perylenyl)propane(Pe-Pr-Pe) dyad. Finally, I present how Machine Learning (ML) can be applied to predict the energies of the frontier orbitals of SubPc based triads functionalized in the periphery with selected ligands. With ML a database of 12.000 structures, with DFT calculated MO energies, can be used to predict the Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) energies of more than 40.000 SubPc triads. Combining these three parts could potentially lead to an efficient screening tool where the best among thousands of potential OPV candidate triads or dyads could be predicted, at a relatively low computational cost. In this way, the improvement of OPV efficiencies could be significantly aided, saving many hours of expensive trial-and-error synthesis work.

UR - https://rex.kb.dk/permalink/f/h35n6k/KGL01012069451

M3 - Ph.D. thesis

BT - Exited by Light

PB - Department of Chemistry, Faculty of Science, University of Copenhagen

ER -