PCAM PhD talk series

For the third talk in our online seminar series, we welcome Oliver Hofmann and Andreas Jeindl from Graz University of Technology. Please contact Katharina to get the link to the online talk.

16.9. Talk No.3

15-15:10 Oliver Hofmann: Studying at Graz University of Technology

15:10 – 15:45 Andreas Jeindl: Physical Insight Into Surface Polymorph Formation for Organic/Inorganic Interfaces

15:45 – 16:00 discussion

Abstract

The ongoing miniaturization in nanotechnology raises the need to understand (and control) the formation of surface polymorphs at a molecular level. Due to the intricate interaction mechanisms,
complex physics and high configurational complexity at play, this understanding is still at the very beginning.In this talk, we will first briefly introduce our in-house-developed structure search algorithm [1] that combines coarse graining, density functional theory and Bayesian learning, to exhaustively predict surface polymorphs. Then, we will showcase the application of this algorithm to predict and understand the formation of surprisingly diverse surface monolayers for a homologous series of acenequinones on Ag(111). [2]
The theoretically predicted structures excellently fit experimental observations within our methodological uncertainties. By performing a detailed analysis of all interaction mechanisms at play,
we are further able to identify three important driving forces governing the motif formation.
Further, the talk will introduce you to our first steps towards predicting electronic interface properties, specifically the role of polymorphism on the work function change, which a monolayer of molecules induces upon adsorption on the surface.[3] By exhaustively predicting the work function changes for millions of polymorph candidates, we can evaluate the work function uncertainties for kinetically trapped as well as thermodynamically stable phases.
[1] Hörmann et al., Comp. Phys. Comm. 244, 2019
[2] Jeindl et al., ACS Nano 14, 4, 6723-6734, 2021
[3] Jeindl et al., arxiv.org:2107.00560, 2021

Find the list of the first 9 talks here.