Institute of Solid State Physics

Oliver Hofmann

Contact: ☎ ✉

People in the Hofmann group
 Fabio Calcinelli
 Johannes Cartus
 Lukas Hörmann
 Andreas Jeindl
 Bernhard Ramsauer
 Fabian Weißenbacher
 Anna Werkovits

   Machine Learning Provides New Insights Into Organic-Inorganic Interfaces
   NVidia supports Machine Learning Activities at the IF
   SAMPLE release
   START Project
   IMPRESS workshop at the TUG
   Computing Time Award
   Huge Computing Time Project Granted
   Defects in Organic Monolayers
   Third Party Funding: 3-year FWF Project

Master projects available
   Autonomous Driving for Nanocars
   Physical Interpretation of Machine Learning Results

   Tuning the Interaction Strength of Inorganic/Organic Interfaces
   Computational Material Design with DFT and Machine Learning
   FWF: Computational Nanotechnology
   Charge Injection Layers at Inorganic/Organic Interfaces
   Defects in Organic Monolayers

   513.127 513.128 Seminar Solid State Physics

Simulation-Driven Material Design

The mission of the Hofmann group is the computational discovery of novel materials and material combinations from first principles. We focus on thin film and interfaces, that are of technilogical relevance for nanotechnology applications, such as organic solar cells and OLED displays. We focus on organic thin films, which often assume particular polymorphs and exhibit properties superior to that of the bulk.

To achieve this mission, my group and I pursue two complementary avenues. One part applies density functional theory (DFT) to pertinent surface science problems at inorganic/organic interfaces, with the goal to identify and push back the limits of the state-of-the-art methodology. The second part of my group develops the machine-learning algorithm "SAMPLE" to predict the structure and the properties of thin film polymorphs.

We are presently working on three complimentary FWF-funded projects. In "Tuning of the Interaction Strength", the purpose is to choose the substrate on which the thin film are grown, in order to obtain materials with specific, desired properties. The project "Defects in Organic Monolayers" investigates the nature and the impact of defects and disorder on the electronic structure. Finally, the project "MAP-DESIGN" aims to develop recipies, which allow to produce predicted materials also experimentally. This will close the gap between computational material design and its realization in a lab.

Our research interests include
  • Structure Determination and Prediction
  • Polymorphism and Metastable Phases
  • Phase Diagrams and Phase Transformations
  • Charge and Energy Transfer Across Interfaces
  • Adsorption Processes of Organic Molecules
  • Defects in Organic Monolayers
  • Spontaneous Symmetry Breaking in Adsorbate Layers
  • Doping and Long-Range Band-Bending in Semiconductors
which we study using:
  • Density Functional Theory (semilocal and hybrid functionals)
  • Band Structure Calculations
  • Machine Learning (Gaussian Process Regression)
  • Ab-initio Thermodynamics
  • Charge-Reservoir Electrostatic Sheet Technique (a QM/MM approach)
(Some) Master and Bachelor projects can be found using the links on the left side of this page. Usually, more are available - inquire within.

Personal data

Featured Videos of Recent Talks and Papers

"Surface Adsorbate Polymorph Prediction with Little Effort - Talk at IPAM, LA, Oct 2017

Video of the talk Surface Adsorbate Polymorph Prediction with Little Effort given at the Optimization and Optimal Control for Complex Energy and Property Landscapes workshop at Los Angles, USA, in Sept 2017.

Video of the talk "Nuts and Bolts of Density Functional Theory", given at the FHI-aims Hands-on Workshop in Berlin, July 2017.

Video abstract for "Doping dependence of the surface phase stability of polar O-terminated (000-1) ZnO", published in The New Journal of Physics, 19 (8), 083012, 2017

Highlighted publications (open access)

O.T. Hofmann, P. Rinke, M. Scheffler, G. Heimel, "Integer versus Fractional Charge Transfer at Metal(/Insulator)/Organic Interfaces: Cu(/NaCl)/TCNE", ACS Nano just accepted, doi: 10.1021/acsnano.5b01164

O.T. Hofmann, V. Atalla, N. Moll, P. Rinke, M. Scheffler, "Interface dipoles of organic molecules on Ag(111) in hybrid density-functional theory", New Journal of Physics, 15, 123028 (2013), doi: 10.1088/1367-2630/15/12/123028

O.T. Hofmann, J.C. Deinert, Y. Xu, P. Rinke, J. Stähler, M. Wolf, M. Scheffler, "Large work function reduction by adsorption of a molecule with a negative electron affinity: Pyridine on ZnO(1010)", Journal of Chemical Physics 139, 174701 (2013) doi: 10.1063/1.4827017

Y. Xu, O.T. Hofmann, R. Schlesinger, S. Winkler, J. Frisch, J. Niederhausen, A. Vollmer, S. Blumstengel, F. Henneberger, N. Koch, P. Rinke, M. Scheffler, "Space-Charge Transfer in Hybrid Inorganic-Organic Systems", Physical Review Letters 111, 226802 (2013) doi: 10.1103/PhysRevLett.111.226802

A. Tkatchenko, L. Romaner, O.T. Hofmann, E. Zojer, C. Ambrosch-Draxl, M. Scheffler: "van der Waals Interactions Between Organic Adsorbates and at Organic/Inorganic Interfaces", MRS Bulletin 35, 435 (2010). doi: 10.1557/mrs2010.581

O.T. Hofmann, D.A. Egger, E. Zojer, “Work-function modification beyond pinning: When do molecular dipoles count?”, Nano Lett. 10, 4369 (2010). doi: 10.1021/nl101874k

The packages below can be downloaded and installed using pip-install packagename Contributor to the FHI aims package

last updated: 04. Jan. 2019