Periodic Reporting for period 3 - CONICALM (Chemistry in Optical Nano Cavities: Designing Photonic Reagents and Light-Matter Materials)
Periodo di rendicontazione: 2023-02-01 al 2024-07-31
Gaining detailed control over chemical reactions has always been a chemists dream. Quantum coherent control has been pursuing this dream by using specially tailored light fields to control chemical reactions on an atomistic level. With the advancement of cavity quantum electrodynamics and its recent application to molecules, using the quantum properties of light to control photochemistry has come into reach.
Recent, groundbreaking experiments have show that one can utilize the vacuum field of an optical nano-resonator to significantly modify the potential energy landscape and thus its photochemistry. The underlying effect is the formation of so-called "dressed states", which are created when the quantized radiation field mode couples to a molecular electronic transition. In the resulting coupled light-matter system, the molecular and the photonic degrees of freedom are heavily mixed. While this effect is well understood for atomic samples, it is not yet fully understood for molecules. The introduction of the nuclear degrees of freedom requires new theoretical frameworks. This effect can be used to modify reaction pathways of chemical and photochemical reactions. This opens a wide range of possibilities to engineer novel types of light driven catalysts.
The major objectives of this proposal are to advance the theoretical understanding of the underlying mechanisms, to build a suitable tool chest for numerical simulations, to use the insight and tools to propose new photochemical applications, and to close the gap between theory and experiment. We will theoretically investigate possibilities to optimize organic solar cells, and the photo catalytic schemes for environmentally relevant molecules.
Recent, groundbreaking experiments have show that one can utilize the vacuum field of an optical nano-resonator to significantly modify the potential energy landscape and thus its photochemistry. The underlying effect is the formation of so-called "dressed states", which are created when the quantized radiation field mode couples to a molecular electronic transition. In the resulting coupled light-matter system, the molecular and the photonic degrees of freedom are heavily mixed. While this effect is well understood for atomic samples, it is not yet fully understood for molecules. The introduction of the nuclear degrees of freedom requires new theoretical frameworks. This effect can be used to modify reaction pathways of chemical and photochemical reactions. This opens a wide range of possibilities to engineer novel types of light driven catalysts.
The major objectives of this proposal are to advance the theoretical understanding of the underlying mechanisms, to build a suitable tool chest for numerical simulations, to use the insight and tools to propose new photochemical applications, and to close the gap between theory and experiment. We will theoretically investigate possibilities to optimize organic solar cells, and the photo catalytic schemes for environmentally relevant molecules.
We have started working on exploring collective effects, which are of fundamental importance in experiments, but not yet very well understood. Our first approach included a simplified model, that allows us to give a better insight and clarify the mechanisms [Davidsson et al., JPCA, 124, 4672 (2020)].
So far, resonators have been assumed to have perfect mirrors in the theoretical computations. However, we know that experiments use rather poor mirrors with a high leakage and yet show clear signatures of strong couplings. We could demonstrate for single molecule model that leaky mirrors, which result in short photon lifetime, play are crucial role in the reaction mechanism by using a high level numerical method [Davidsson et al., JCP, 153, 234304 (2020)].
Non-adiabatic dynamics and the radiation less decay it causes, plays a crucial role in the photochemistry of many molecular systems. It is thus is an objective of the project to understand how the non-adiabatic dynamics in molecules is modified by strong coupling. We were able to show how the lifetime of excited state molecules can be modified in a quantized light field by using the photo-induced deprotonation of pyrrole [Gudem et al., JPCA, 125, 1142 (2021)]
We have investigated the possibility of optimizing dye sensitizers in solar cells by means of strong coupling to nano-cavities [Couto et al., PCCP, 24, 19199 (2022)]. Here our main focus was the influence of the cavity on the non-radiative decay. Our results show that higher couping strengths can, in principle, accelerate the excited state decay, and in a narrow parameter regime also stabilize the excited state.
So far, resonators have been assumed to have perfect mirrors in the theoretical computations. However, we know that experiments use rather poor mirrors with a high leakage and yet show clear signatures of strong couplings. We could demonstrate for single molecule model that leaky mirrors, which result in short photon lifetime, play are crucial role in the reaction mechanism by using a high level numerical method [Davidsson et al., JCP, 153, 234304 (2020)].
Non-adiabatic dynamics and the radiation less decay it causes, plays a crucial role in the photochemistry of many molecular systems. It is thus is an objective of the project to understand how the non-adiabatic dynamics in molecules is modified by strong coupling. We were able to show how the lifetime of excited state molecules can be modified in a quantized light field by using the photo-induced deprotonation of pyrrole [Gudem et al., JPCA, 125, 1142 (2021)]
We have investigated the possibility of optimizing dye sensitizers in solar cells by means of strong coupling to nano-cavities [Couto et al., PCCP, 24, 19199 (2022)]. Here our main focus was the influence of the cavity on the non-radiative decay. Our results show that higher couping strengths can, in principle, accelerate the excited state decay, and in a narrow parameter regime also stabilize the excited state.
In the initial phase of the project, we have started to work on different effects, which are believed to be important. Our main approach is to begin with simplified models that integrate single effects and allow us to gain a better understanding of their influence.
This strategy has proven successful during so far. In the second half of the project we will combine effects, which has been identified to be of major importance, and build an advanced simulation technique.
In the beginning of the project, we have explored some basic effects to identify the importance of some basic effects and gauge the general direction for the future. Beyond the results mentioned in the
previous section, we have started to do preparatory work to explore more molecular systems with relevance for environmental chemistry and for the development of advanced computational methods such the tensor propagation methods.
An investigation into the optimization of dye sensitizers in solar cells via strong coupling has been successfully completed.
By the end of the action, we expect to have working computational techniques for the simulation of complex collectively coupled systems
as well as simulations with these models, which clarify the reaction mechanisms.
It is expected that we can also suggest potential application scheme for specific molecular species.
This strategy has proven successful during so far. In the second half of the project we will combine effects, which has been identified to be of major importance, and build an advanced simulation technique.
In the beginning of the project, we have explored some basic effects to identify the importance of some basic effects and gauge the general direction for the future. Beyond the results mentioned in the
previous section, we have started to do preparatory work to explore more molecular systems with relevance for environmental chemistry and for the development of advanced computational methods such the tensor propagation methods.
An investigation into the optimization of dye sensitizers in solar cells via strong coupling has been successfully completed.
By the end of the action, we expect to have working computational techniques for the simulation of complex collectively coupled systems
as well as simulations with these models, which clarify the reaction mechanisms.
It is expected that we can also suggest potential application scheme for specific molecular species.