The synthesis of graphene and h-BN have been achieved on Ag(111) and Cu(111) and explored by AFM/STM. Efforts are underway to synthesize the theoretically predicted semiconductor silicon carbide (SiC). However in order to maximise the outcome of the project, in view of our recent results in graphene on Ag(111), we have adjusted the phases of the project to give priority to the objective 4 related with the chemical functionalization of the 2D layers. Unlike on many other transition-metal supports, the carbon sheets on Ag(111) only interact weakly with the noble metal substrate, resulting in a promising substrate for graphene-edge functionalization. Specifically, we achieved an in-situ covalent dehydrogenative coupling mechanism yielding – for the very first time – tetrapyrroles fused to graphene edges. Currently we are at the process of extending the functionalization approach to other molecules with different functionalities.
In the second half of the project we pursued objectives 2 and 3. In particular, we have initiated an effort to create heterostructures combining graphene and h-BN, as it was envisaged in objective 2.
A detailed evolution of the work plan of the project is present hereafter.
WP1: Setting up of the working environment.
During the first months of the project, the required facilities for the development of the project were implemented (C and Si evaporators, gas line (C2H4), Peltier cooler for Borazine, etc.). The researcher was also trained under the supervision of the Prof. Willi Auwärter and collaborators in the use of the new experimental techniques (AFM and XPS). As a result, deliverable D1.1 has been already achieved.
WP2: Synthesis and characterization of novel 2D structures on metals.
The synthesis of graphene and h-BN has been already accomplished on the Cu(111) surface by chemical vapor decomposition (CVD) of ethylene and borazine with good results. For the Ag(111) crystal, different synthesis protocols has been investigated (D2.1) with the results summarize in the image 1.
WP3: Functionalization of 2D sheets by reactive sites enabling an out-of-plane tethering of adsorbates.
We propose the use of reactive sites and unsaturated dangling-bonds produced by the creation of defects, for an out-of-plane tethering of atom and molecular species. The most promising functionalization method for graphene sheets (D3.1) has been shown to be surface-assisted covalent coupling of simple molecular species to graphene edges.
WP4: Promotion, dissemination and networking.
Up to now, where this report is being written, the project has resulted in several publications (D4.1) and the work accomplished has been presented in international conferences. In addition, the researcher has participated in different TUM outreach activities to transfer the knowledge gained to students and extra-academic context.
CONFERENCES
Summer School SFB667
Hohwacht
27– 28 Sep 2017
Invited talk
Porphyrin Molecules at Interfaces: Insight from Scanning Probe Microscopy
M Garnica
19th International Conference on Non-contact Atomic Force
Nottingham
25 – 29 Jul 2016
Oral presentation
Surface-assisted synthesis and edge-functionalization of graphene on Ag(111)
M Garnica et al
3rd European Workshop on Epitaxial Graphene and 2D Materials
Bergisch Gladbach
17 – 21 May 2016
Oral presentation
Surface-assisted synthesis and edge-functionalization of graphene on Ag(111)
M Garnica et al
31st European Conference on Surface Science (ECOSS-31)
Barcelona
31 Aug - 4 Sep 2015
Oral presentation
Comparative atomic-scale scanning probe microscopy study of graphene and boron nitride on noble metals surfaces
M Garnica et al
OUTREARCH ACTIVITIES
Tag der offenen Tür
21 Oct 2017
Guide lab-tour
Tag der Physikerinnen
17 June 2016
Lange Nacht der Wissenschaft
27 June 2015
Guide lab-tour scanning tunnelling microscope.
Tag der Physikerinnen
23 June 2015
WP5: Management.
Regular meetings are evaluating the practical details, the experimental results and the current relevant literature, so that the milestones are adjusted accordingly. In particular:
• Collaborations with international research institutions have been established in order to acquire molecules needed to fulfill the project objectives. (Interface and Surface Science Laboratory, Matthias Batzill Group (Tampa, US); Nanosurf Lab, Pavel Jelinek Group (Prague, Czech Republic), Davide Bonifazi (Cardiff University, UK))
• Links with industrial providers are permanently open to solve any experimental incident in the lab.
• Dissemination of results are set, including the writing of papers and the preparation of talks for congresses.
• The pedagogical competences of the fellow have been enhanced through the day-to-day supervision of three PhD students.
