Håkan Hugosson
Senior Lecturer, Docent
About the researcher
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Modern electron structure calculations reveal the quantum mechanical orbits of electrons around atoms and are the basis for complex computer simulations that can theoretically determine the properties of materials and molecules. Here, these calculations, performed on massively parallel computers at national and international supercomputing centers, are used to find ways to improve the properties of so-called thermoelectric polymers, a type of material that converts heat differences into the electricity we need for a transition to more sustainable energy production.
Doctoral Degree
2001, Computational Physics, Uppsala University, Title: "A Theoretical Treatise on the Electronic Structure of Designer Hard Materials"
Supervisor: Professor B. Johansson, O. Eriksson and U. Jansson. Faculty opponent: Professor S. G. Louie, University of California Berkeley, USA.
University Degrees
- 1996, Bachelor of Science in Physics, Uppsala University.
- 1999, Licentiate of Philosophy in Computational Physics, Uppsala University. Faculty opponent: Professor M. Brooks, Karlsruhe, Germany.
Current employment
- Associate Professor of Physics at the Department of Electrical Engineering, Mathematics and Natural Sciences, University of Gävle, Sweden.
Previous Positions
- Senior Researcher, Division of Materials and Nanophysics, KTH Royal Institute of Technology, Stockholm, Sweden.
- Senior researcher at the Division of Theoretical Chemistry, Department of Biotechnology, Royal Institute of Technology (KTH), Stockholm, Sweden.
- PhD student in condensed matter theory, Department of Physics, Uppsala University, Sweden. Supervisors: Professor O. Eriksson, Professor U. Jansson and Professor B. Johansson.
Postdoctoral Positions
- Postdoctoral position at Professor H. Ågrens group for theoretical chemistry, Royal Institute of Technology (KTH), Sweden.
- Postdoctoral fellow at Prof. U. Röthlisberger's group for Computational Chemistry and Biochemistry, ETH/EPF Zurich and Lausanne, Switzerland.
- Postdoctoral fellow at Sandvik Coromant AB, Applied Materials Science, KTH and the Thin Film Physics Group, Linköping University, Sweden.
Formal Supervision
- Postdoctoral fellow, A. M. Natarajan, 2008–2010.
- Co-supervisor of PhD student Amina Mirsakiyeva, 2012–2016. Licentiate degree 150826.
- Co-supervisor of PhD student Karim Elgammal, 2015–2016. Licentiate degree 160219.
Dynamic quantum mechanical simulations of materials at multiple scales
The study of our physical environment through quantum mechanical (QM) calculations of the electron structures of materials and molecules is an ever-growing area of research. Electron structure calculations have proven to be useful in many sciences; from solid state physics to pharmacology. They have not only increased the understanding of experimental results but have also shown that they can predict important properties and thus enable the rational design of molecules and materials on the basis of these theoretical predictions. Calculations of electronic structures have even established themselves in biology, the science of life itself. With this increased scientific understanding and possible applications to challenges in areas such as medicine and nanotechnology, electronic structure calculations have a huge potential impact, even on the everyday world around us.
The scope of electronic structure calculations is further extended in quantum or ab-initio molecular dynamics (QMD/AI-MD), where the entire dynamics of the system, the motions of atoms, at realistic temperatures are simulated. One of the most important theoretical techniques for studying large systems at room temperature, important for e.g. biological or polymeric systems, is so-called molecular dynamics (MD) simulations. In MD, the system is described as a set of particles moving according to the laws of classical mechanics over a given potential energy surface. Depending on how the interactions between the particles are obtained, MD methods can be divided into classical force field MD methods or quantum mechanical MD methods. Although classical force-field MD methods, which are by far the most widely used method, are very successful for the simulation of many biological and polymeric systems, chemical reactions and more complex atoms, e.g. transition metals, can only be satisfactorily treated using a full quantum mechanical description. In quantum mechanical MD (QMD) methods, all interactions are calculated from an electron structure method (here density functional theory – DFT). QMD simulations are therefore parameter-free and allow a direct and potentially unbiased simulation of chemical and physical events. Since the temperature of the systems is taken into account, a selection of the conformational space, possible geometries, is made, which also means that the simulations are less influenced by the choice of, for example, initial conditions and selected reaction coordinates.
Thermoelectric polymers
To meet the increasing demand for electricity in the world (estimated to double to 26 TW by 2050), we are constantly looking for alternative renewable energy sources that can be converted into electricity. Since the sun is the largest available energy source, which could easily meet our energy needs with a radiant power in the order of 100 000 TW, converting solar energy into electricity is very appealing. One of the most promising ways to convert solar heat into electricity is to use thermoelectric generators (TEGs). TEGs are constructed using thermoelectric materials, materials in which a difference in temperature causes an electric current to flow through the materials, the so-called Seebeck effect. The disadvantages of the inorganic thermoelectric materials currently in use are that they consist of toxic elements with low natural abundance. Organic polymer-based thermoelectric materials, on the other hand, while currently less efficient, can be mass-produced using safer, highly abundant elements at low cost.
Termoelektriska generatorer konstrueras med hjälp av termoelektriska material men Seebeckkoefficienterna, förmågan att omvandla en temperaturskillnad till elektrisk ström i materialen, varierar kraftigt från 10-3 till 10-6. Termoelektriska anordningar består av många termoelektriska par – ett termoelektriskt material med negativa laddningsbärare (n-typ) och det andra med positiva laddningsbärare (p-typ) som är elektriskt kopplade i serie och termiskt parallellt. För att uppnå en betydande Seebeckspänning måste det finnas en stor kvarstående temperaturskillnad över termoelementet.Termoelektriska generatorer konstrueras med hjälp av termoelektriska material men Seebeckkoefficienterna, förmågan att omvandla en temperaturskillnad till elektrisk ström i materialen, varierar kraftigt från 10-3 till 10-6. Termoelektriska anordningar består av många termoelektriska par – ett termoelektriskt material med negativa laddningsbärare (n-typ) och det andra med positiva laddningsbärare (p-typ) som är elektriskt kopplade i serie och termiskt parallellt. För att uppnå en betydande Seebeckspänning måste det finnas en stor kvarstående temperaturskillnad över termoelementet.
We therefore need materials with both:
- a high Seebeck coefficient (to generate a large Seebeck voltage)
- high electrical conductivity (to easily move the charge carriers)
- low thermal conductivity (to maintain the temperature difference).
These three properties are not easily combined; metals, for example, are both highly thermally conductive and good electrical conductors, and therefore good thermoelectric materials are hard to find. Among the organic polymer-based thermoelectric materials that are the subject of intense interest in the research community, doped poly(3,4-ethylenedioxythiophene) (PEDOT) is widely used, see Figure 1, which has thermoelectric capability, high electrical conductivity, low thermal conductivity and does not decompose in air. PEDOT therefore appears as a very promising candidate to be the material of future thermoelectric generators.
Our simulations of PEDOT
Currently, the strategies to increase the thermal power of PEDOT include doping with anions, such as polystyrene sulfonate (PSS), tosylate ions (Tos) or transition metal ions. In our simulations, we study both uncharged and charged PEDOT, undoped and doped with anions, as well as PEDOT oligomers in the polymeric state (1D chain) and in the 3D crystal state using quantum mechanical molecular dynamics. Despite extensive use of PEDOT and a wealth of data from various experimental techniques, the atomic-scale descriptions of its electronic and geometric structures are still incomplete, and in particular the charge-carrying polarons in these systems are not fully understood.
This page was last updated 2025-01-08