On-surface synthesis of organic nanostructures
Title: On-surface synthesis of organic nanostructures
SNIC Project: SNIC 2021/5-236
Project Type: SNIC Medium Compute
Principal Investigator: Jonas Björk <jonas.bjork@liu.se>
Affiliation: Linköpings universitet
Duration: 2021-05-01 – 2022-05-01
Classification: 10407 10402 10304
Homepage: https://www.ifm.liu.se/theomod/compphys/jonbj.xml


The project concerns the study of organic nanostructures formed though on-surface synthesis. On-surface synthesis is becoming an increasingly popular approach for creating atomically precise organic nanostructures, through the coupling of molecular building blocks on surfaces, with great relevance and prospects in for example organic electronics. However, very little is known about the on-surface reactions, which makes them arduous to control. Fundamental understanding of the underlying on-surface reactions is therefore of great interest. Furthermore, knowledge is needed for how the structures of the formed materials govern their electronic properties and how the electronic properties of the materials are affected by defects. Such understanding would guide the development of materials with specific electronic properties. The proposed project is divided into two parts. In the first part of the project we will investigate the formation mechanisms of organic nanostructures from molecular building blocks, providing insight into the underlying surface chemistry of these reactions. Previous year we have demonstrated important insight into the cyclodehydrogenation reaction, which is one of two reactions important for the formation of graphene nanoribbons. During the upcoming year, we intend to study fundamental aspects of the other type of reaction important for graphene nanoribbons, namely the on-surface Ullmann coupling. This part of the project will be carried out by density functional theory combined with methods for studying reaction paths, such as the Nudged Elastic Band and Dimer methods, as implemented in the VASP code. In the second part of the project we will investigate electronic properties of organic nanostructures. This will also to a large extent be performed by density functional theory with the VASP code. Furthermore, we will use our own code BandUP, which allows for band structure calculations of defective materials, with respect to their primitive unit cell by so-called band unfolding techniques. The BandUP code has been developed on previous NSC resources and has been tested on Tetralith.