Department of Chemistry and Molecular Biology,
University of Gothenburg
412 96 Gothenburg Sweden
karl.borjesson (at) gu.se
Chemistry building, Campus Johanneberg
Chemistry has had profound impact on society during the last two centuries. From mass production of drugs and pigments, to the invention of plastics, and more recently with the introduction of molecular electronics. However, some basic physical laws govern possible utilizations. It is therefore of great importance to examine how to bend these laws, how to bypass them and by so doing open up new opportunities for novel applications. A common way of envision the creation of molecular orbitals is through the hybridization of atomic orbitals. It is perhaps less known that electronic states in molecules and atoms can hybridize with light or vacuum fields to create hybrid light matter states. So called strong exciton-photon coupling occurs when light-matter interactions are large, and it is manifested through new hybrid light-matter states called cavity polaritons. The ERC-stg project - Strong Coupling Between Molecules and Vacuum Fields: New Molecular Properties (STRONG) - uses a chemical viewpoint to develop unique molecules optimized for strong light-matter interactions, and with these examine excited state processes of strongly coupled systems. The main aim of STRONG is to demonstrate that strong light-matter coupling enables selective manipulation of energy levels. By so doing allowing for a singlet ground and first excited state, thus challenge Hund’s rule and change how the basic rules of electronic state energetics are envisioned. This enables channelling of all excitation energy, irrespectively of origin, through a singlet pathway, which is of great technological importance in organic electronics.
Advanced Science, 2019, DOI:10.1002/advs.201801650.
Excitation energy transfer through dipole-dipole interactions can efficiently mediate energy between molecules at fairly large distances. In this so called Förster type energy transfer the transition dipole moments on the energy donor and acceptor couple so that excitation energy is transferred between the two molecules. The efficiency of the energy transfer depends not only on the strength of the transition dipole moments, but also on their relative orientation. Our research efforts aim at both studying this process at a fundamental level and also use it to increase the efficiency of molecular electronic devices. Recent advances includes the demonstration that the process works between states of different multiplicity.
Jounal of Physical Chemistry A, 2020,DOI:10.1021/acs.jpca.0c05035
Nanostructured materials made from highly controlled synthetic and supramolecular chemical reactions are becoming increasingly important to solve challenges related to energy storage and clean air. An upcoming material that already has shown a high potential in many of these aspects is the covalent organic framework (COF), which is a metal free, lightweight development from the metal organic framework (MOF). We have developed a platform for synthesising smooth films of 3D organic covalent frameworks, and by doing so, have opened up a range of new research directions where substrate connection, and film connectivity is a requirement.
Journal of the American Chemical Society, 2020, 142, 14, 6548–6553.
Triplet-triplet annihilation photon upconversion (TTA-UC) provides the possibility to convert low to high energy photons at low irradiation conditions. It is thus considered as a promising method to increase the efficiency of solar energy conversion systems like photocatalysis and solar cells. Our research aims at developing concepts for making this, in solution highly efficient, process efficient in the solid state. By doing so, we would bridge academic interest for the fundamental process with real world usability.
Journal of the American Chemical Society, 2020,142, 23, 10468–10476.
Physical Chemistry Chemical Physics, 2020, 22, 1715 - 1720.
Molecular switches are capable of isomerizing between two different states, when exposed to an external stimulus such as light. The two isomers can have remarkably contrasting properties (e.g. electronic, optical, mechanical), which have made them popular in many applications. We have used the change in electronic properties between the two isomers as a light triggered on/off button in organic field effect transistors, and used non-isoenergetic isomers to capture and store solar energy. Our research efforts aims at developing new switches with improved properties as to expand the potential field of applications for this class of interesting molecules.
Advanced Functional Materials, 2020, 1907507.
Energy and Environmental Science, 2019, 12,187-193
Advanced Energy Materials, 2018, 8 (18), 1703401
Energy and Environmental Science, 2017, 10, 728-734
Scientific Reports, 2017, 7:41145, DOI:10.1038/srep41145
Copyright C 2015 Karl Börjesson | University of Gothenburg | Department of Chemistry and Molecular Biology. All Rights Reserved.