Reactivity, Energetics and Structure of Buried Organic/Metal Interfaces

Summary

Chemical reactions and diffusion processes at buried metal/organic interfaces lead to the formation of reaction zones (interphases), which can greatly influence the properties of contacts between metals and organic semiconductors. The chemical, electronic, energetic and kinetic aspects of the interphase formation are investigated using Hard X-ray Photoelectron Spectroscopy (HAXPES) for chemical depth profiling, Nanojoule Calorimetry (NC), and complementary methods.

Ongoing HAXPES and NC studies of metal deposition onto molecular solids at variable temperatures will be continued and extended to thermally sensitive molecules. Their deposition is possible with the newly established Electrospray Ionization Ion Beam Deposition (ESI-IBD) and complementary Neutral Spray Deposition (NSD). The influences of defects on the interface reactivity will be systematically explored using model metal/organic interfaces based on well-defined vicinal (stepped) metal surfaces.

As a new class of model systems, covalent heterointerfaces with thiol-anchored organic molecules on transition metal dichalcogenides are introduced. The potential of the HAXPES depth profiling technique will be further exploited to study diffusion processes at model organic/organic interfaces and to retrieve spatial band bending information for semiconductor interfaces.

Project-related publications

1. M. Schmid, S.R. Kachel, B.P. Klein, N. Bock, P. Müller, R. Riedel, N. Hampp, J.M. Gottfried
   Reactive Metal-Organic Interfaces Studied with HAXPES: Controlled Formation of Metalloporphyrin Interphase Layers During Metal Vapor Deposition onto Porphyrin Films
   J. Phys. Condens. Matter 31, 094002 (2019).
2. M. Zugermeier, J. Herritsch, J.-N. Luy, M. Chen, B.P. Klein, F. Niefind, P. Schweyen, M. Bröring, M. Schmid, R. Tonner, J.M. Gottfried
   On-Surface Formation of a Transient Corrole Radical and Aromaticity-Driven Interfacial Electron Transfer
   J. Phys. Chem. C 124, 13825 (2020).
3. B.P. Klein, N. van der Heijden, S.R. Kachel, M. Franke, C.K. Krug, K.K. Greulich, L. Ruppenthal, P. Müller, P. Rosenow, S. Parhizkar, F.C. Bocquet, M. Schmid, W. Hieringer, R.J. Maurer, R. Tonner, C. Kumpf, I. Swart, J.M. Gottfried
   Molecular Topology and the Surface Chemical Bond: Alternant vs. Non-Alternant Aromatic Systems as Functional Structural Elements
   Phys. Rev. X 9, 011030 (2019).
4. S.R. Kachel, B.P. Klein, J.M. Morbec, M. Schöniger, M. Hutter, M. Schmid, P. Kratzer, B. Meyer, R. Tonner, J.M. Gottfried
   Chemisorption and Physisorption at the Metal/Organic Interface: Bond Energies of Naphthalene and Azulene on Coinage Metal Surfaces
   J. Phys. Chem. C 124, 8257 (2020).
5. B.P. Klein, S.E. Harman, L. Ruppenthal, G.M. Ruehl, S. Hall, S.J. Carey, J. Herritsch, M. Schmid, R.J. Maurer, R. Tonner, C.T. Campbell, J.M. Gottfried
   Enhanced Bonding of Pentagon–Heptagon Defects in Graphene to Metal Surfaces: Insights from the Adsorption of Azulene and Naphthalene to Pt(111)
   Chem. Mater. 32, 1041 (2020).