Speeding up Modelling of Organic Light-Emitting Diodes

About the PhD project

Organic Light-Emitting Diodes (OLEDs) are revolutionizing the display and lighting industry. OLED displays in smartphones are nowadays commonplace while OLED TVs show a rapid breakthrough, replacing liquid crystal display (LCD) screens. Because of their large emission area as compared to inorganic LEDs, OLEDs also offer completely new possibilities for lighting applications. Bendable and foldable OLEDs have been demonstrated in the lab and will soon appear on the market. Advanced modelling of the functioning of OLEDs is essential for sustaining these rapid technological developments. Our group and the company Simbeyond, a spin-off of our group and partner in this project, are developing advanced modelling tools for Organic Electronics, and in particular OLEDs. The key aspect of these modelling tools is the statistical simulation of the quantum mechanical processes, involving the dynamics of electrons, holes, and excitons (electron-hole pairs) by their transfer between the molecules of the organic materials. To this end, our group and Simbeyond have developed so-called kinetic Monte Carlo (KMC) tools that are presently used by OLED developers all over the world.

Despite their success, KMC tools have a serious drawback: they are slow. There is great demand for simulation tools that have a comparable accuracy as KMC, but are much more efficient. The development of such tools is the main goal of the PhD project. The starting idea is to efficiently solve a so-called Master Equation for the occupational probabilities of molecules by electrons, holes, and excitons, using the result of KMC simulations as benchmark. We have already demonstrated that this idea works for calculating the transport and recombination of electrons and holes in specific types of OLEDs [F. Liu et al., Phys. Rev. Appl. 10, 054007 (2018)]. The PhD should extend this idea to all types of OLEDs, and also include the excitonic processes that determine the efficiency at large brightness levels. The study of exciton dynamics (“excitonics”) is expected to lead to interesting new fundamental insights into the operation of OLEDs based on various emission concepts, such as emission by state-of-the-art phosphorescent emitters and so-called Thermally Assisted Delayed Fluorescence (TADF).

You will carry out the work in the group Molecular Materials and Nanosystems (M2N) in the Department of Applied Physics at the Eindhoven University of Technology under supervision of Prof. dr. Peter A. Bobbert and Prof. dr. Reinder Coehoorn. You will work in a team with other PhDs and postdocs focusing on computational as well experimental studies of Organic Electronics, and intensively collaborate with researchers from Simbeyond (http://www.simbeyond.com/).

Job requirements

You are excited about the field of Organic Electronics and in particular OLEDs. You have a MSc in (Theoretical) Physics, Chemistry, Materials Science or Mathematics, with sufficient knowledge of quantum mechanics and skills in scientific software development. Preferably, you have followed courses in Quantum Physics, Statistical Physics, Quantum Chemistry and/or Computational Physics. You are able to collaborate in a strongly interdisciplinary and technology-oriented team.

You can apply for this position at the TU/e web site