Kristian Berland

Image of Kristian Berland
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Mobile phone 45679296
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Visiting address Gaustadalléen 23C MiNaLab 0373 OSLO
Postal address Postboks 1048 Blindern 0316 OSLO

Research

My scientific background is in modeling and developing tools for van der Waals interactions as well as semiconductor heterostructure physics. Currently, I am part of Prof. Clas Persson theory group at Structure Physics. This group has a general expertise on first-principle modeling of energy materials. In particular, I model thermoelectric materials as part of the national THELMA project.  Starting fall 2017, emphasis will shift back to modeling van der Waals materials as part of a national project in collaboration with theoreticans from the Casimir field. 

Modeling of thermoelectric materials

Method development

A key challenge in accurate modeling of thermoelectric properties in the Boltzmann transport formalism is a sufficiently dense sampling of the Brillouin zone. To tackle this , we have developed a new  \(\mathrm{k}\dot\,\mathrm{p}\, \)based interpolation scheme (https://arxiv.org/abs/1607.01429).  We are currently employing this scheme for a number of problems related both to thermoelectric transport and optical absorption. 

 

Half Heuslers

 

Simen N. H. Eliassen studied the thermal transport of (TiZrHf)NiSn in his master thesis work. The paper is now available at https://arxiv.org/abs/1607.01429

Half  Heuslers are ternary compounds that can be viewed as an interpenetrating zinc-blende and rock-salt structure. Since three elements can be combined in many different ways and still form a closed shell, Half Heuslers  makes it possible to use inexpensive, earth-abundant and environmentally friendly elements in applications such as thermoelectronics (solid state conversion of heat to electric power). Together with SINTEF and experimentalists at Structure Physics and IFE, we are exploring and optimizing these materials for thermoelectric applications. 

 

 

 

 

van der Waals forces in condensed matter

Non-local correlation functionals

The van der Waals density functional (vdW-DF) has been amazingly successful in extending density functional theory calculation to materials bound together by van der Waals forces. For an overview consult our extensive review  van der Waals forces in density functional theory: a review of the vdW-DF method. In the recent paper Spin Signature of Nonlocal Correlation Binding in Metal-Organic Frameworks, we also extended the method to spin-polarized systems. 

Even if the modern variants of the functional, such as the vdW-DF-cx, have good performance for many systems, there are many physical effects than can be better accounted for. An example is the underlying electrodynamical screening in the method. The immense progress in the manufacturing of layered van der Waals heterostructures is also motivated developing more accurate methods, so is the desire to accurately model water, adsorption, and interactions between biomolecules. Currently, we are extending the method to encompass hybrid-exchange effects togheter with the Hyldgaard team at Chalmers. 

Casimir interactions in environmental systems

Beyond the regime of systems that can be modeled with density functional theory, longer length scales not only demand a more macroscopic approach but also require that retardation effects are accounted for. 

Collaboration

Collaborations with many international groups, including

Tomic Stanko, U. Salford

Jeff Neaton, UC Berkeley, 

Per Hyldgaard, Chalmers 

T. L. Einstein, University of Maryland

Valentino Cooper, Oak Ridge

T. Thonhauser, Wake Forest University

Background

2007 Master thesis at NTNU, theoretical high-energy physics. 

2007 -2012 PhD at Chalmers University of Technology in the group of Prof. Per Hyldgaard

2012- 2014 Post Doc at Chalmers Universtiy of Technology, including a 6 months visit to Berkeley lab. 

2014 Post Doc at University of Oslo

Teaching

I teach the course Quantum mechanical modeling of nanomaterials. This is a practical theory course, were student learn the skills to efficiently execute research projects were density functional theory calculations is an ingredient. The course does not only cover basic details but also emphasize good research practice in the field. 

Taking advantage of the fact that there are typically only about 10 students, the course has been made quite interactive. 

Master students

Simen Nut Hansen Eliassen (alumni), now PhD student at NTNU. 

 

Tags: Thermoelectric materials, van der Waals systems, vdW-DF, Heterostructures

Publications

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  • Berland, Kristian (2017). Perspectives on van der Waals functionals.
  • Berland, Kristian; Eliassen, Simen Nut Hansen; Schrade, Matthias; Tofan, Raluca; Guzik, Matylda Natalia; Gunnæs, Anette Eleonora; Finstad, Terje; Katre, Anikta; Madsen, Georg; Persson, Clas & Løvvik, Ole Martin (2017). Using theory to understand thermoelectric materials.
  • Berland, Kristian; Løvvik, Ole Martin & Persson, Clas (2017). How hybrid exchange affects thermoelectric transport properties of GaAs, PbTe, Cu2Se, and half Heuslers: Accurate grid sampling enabled with a corrected k.p scheme.
  • Berland, Kristian & Persson, Clas (2017). Computing accurate dielectric functions and transport properties of semiconductors with help of a new k.p based interpolation scheme.
  • Berland, Kristian & Persson, Clas (2017). The need for dense Brillouin zone sampling in transport and optical calculations... and how to deal with it.
  • Berland, Kristian; Zamulko, Sergii & Persson, Clas (2017). Resolving fine features of the dielectric function: Computational issues and opportunities.
  • Berland, Kristian; Eliassen, Simen Nut Hansen; Katre, A; Madsen, Georg; Løvvik, Ole Martin & Persson, Clas (2016). Optimizing the thermoelectric properties of (TiHfZr)NiSn alloys.
  • Berland, Kristian; Eliassen, Simen Nut Hansen; Katre, Anikta; Madsen, Georg; Persson, Clas & Løvvik, Ole Martin (2016). How to bring down the thermal conductivity of MNiSn Half-Heuslers - a theoretical analysis.
  • Berland, Kristian & Persson, Clas (2016). A corrected k.p scheme for accurate electronic properties.
  • Berland, Kristian & Persson, Clas (2016). Enabling accurate transport calculations with a k.p-method based interpolation scheme: Applications to thermoelectric properties.
  • Berland, Kristian; Persson, Clas & Tomic, Stanko (2016). STSM Report: Connecting the ab initio atomistic with continuum modeling: parameterization.
  • Løvvik, Ole Martin; Eliassen, Simen Nut Hans; Berland, Kristian; Song, Xin; Schrade, Matthias; Shulumba, N.; Hellman, O.; Katre, A & Madsen, G. (2016). Predicting the thermoelectric figure of merit from first principles.
  • Løvvik, Ole Martin; Eliassen, Simen Nut Hansen & Berland, Kristian (2016). Transport calculations of thermoelectric materials from first principles.
  • Løvvik, Ole Martin; Eliassen, Simen Nut Hansen; Berland, Kristian & Peters, Thijs (2016). Transport in materials – understanding the motion of electrons, atoms, and phonons.
  • Løvvik, Ole Martin; Eliassen, Simen Nut Hansen; Berland, Kristian & Peters, Thijs (2016). Transport properties of functional materials – understanding the motion of electrons, atoms, and phonons.
  • Schrade, Matthias; Echevarria-Bonet, Cristina; Eliassen, Simen Nut Hansen; Berland, Kristian; Persson, Clas; Tofan, Raluca; Løvvik, Ole Martin; Gunnæs, Anette Eleonora & Finstad, Terje (2016). Thermal Properties of XNiSn(X = Hf, Zr, Ti) half Heusler Alloys.
  • Schrade, Matthias; Echevarria-Bonet, Cristina; Guzik, Matylda Natalia; Tofan, Raluca; Gunnæs, Anette Eleonora; Eliassen, Simen Nut Hansen; Berland, Kristian; Persson, Clas; Løvvik, Ole Martin & Finstad, Terje (2016). Thermal properties of XNiSN (X = Ti, Zr, Hf) half Heusler alloys.
  • Tofan, Raluca; Echevarria-Bonet, Cristina; Berland, Kristian; Schrade, Matthias; Sørby, Magnus Helgerud; Hauback, Bjørn Christian; Persson, Clas; Prytz, Øystein; Hansen, Vidar & Gunnæs, Anette Eleonora (2016). Microstructural characterization of spark plasma sintered (X,X’)NiSn half‐Heusler alloys.
  • Tofan, Raluca; Echevarria-Bonet, Cristina; Berland, Kristian; Schrade, Matthias; Sørby, Magnus Helgerud; Hauback, Bjørn Christian; Persson, Clas; Prytz, Øystein; Hansen, Vidar & Gunnæs, Anette Eleonora (2016). The effect of spark plasma sintering on structure and phase stability in half-Heusler thermoelectric alloys.
  • Zamulko, Sergii; Berland, Kristian; Platzer-Björkman, Charlotte & Persson, Clas (2016). First-principles analysis of Cu2ZnSn(S,Se)4 alloys for solar cell application.
  • Berland, Kristian; Lee, Kyuho; Sharifzadeh, Sahar & Neaton, Jeffrey B. (2015). Electronic and optical properties of a metal-organic framework with ab initio many-body perturbation theory .
  • Berland, Kristian; Lindberg, Per Filip & Persson, Clas (2015). Solceller kommer til å være overalt. Aftenposten Viten.
  • Berland, Kristian & Persson, Clas (2015). The role of the exchange account in density functional theory calculations of thermoelectric properties.
  • Eliassen, Simen Nut Hansen; Berland, Kristian & Løvvik, Ole Martin (2015). FIRST PRINCIPLE CALCULATIONS OF THERMAL CONDUCTIVITY IN HALF-HEUSLER COMPOUNDS.
  • Gordillo, Tonatiuh Rangel; Sharifzadeh, Sahar; Berland, Kristian; Altvater, Florian; Lee, Kyuho; Hyldgaard, Per; Kronik, Leeor & Neaton, Jeffrey B. (2015). Van der Waals Dispersion Interactions and Excited States of Oligoacene Molecular Crystals.
  • Hyldgaard, Per; Berland, Kristian & Schröder, Elsebeth (2015). A van der Waals density functional built upon the electron-gas foundation .
  • Løvvik, Ole Martin; Eliassen, Simen Nut Hansen; Berland, Kristian; Flage-Larsen, Espen; Jensen, Ingvild Julie Thue; Peters, Thijs & Carvalho, Patricia (2015). Transport Properties of Materials from First Principles.
  • Løvvik, Ole Martin; Eliassen, Simen Nut Hansen; Berland, Kristian; Peters, Thijs & Song, Xin (2015). Nanostructures for energy applications - a brief tour of activities in Oslo.

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Published Dec. 19, 2014 12:01 PM - Last modified Nov. 23, 2016 2:44 PM