| Autor: |
Amsalem, P., Wilke, A., Frisch, J., Niederhausen, J., Vollmer, A., Rieger, R., Müllen, K., Rabe, J. P., Koch, N. |
| Předmět: |
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| Zdroj: |
Journal of Applied Physics; Dec2011, Vol. 110 Issue 11, p113709, 6p, 2 Diagrams, 3 Graphs |
| Abstrakt: |
In this paper, we investigate by photoemission the electronic properties of an organic/organic interface consisting in a strong electron acceptor hexaazatriphenylene-hexacarbonitrile (HATCN) deposited on a physisorbed N,N′-bis(1-naphthyl)-N,N′-diphenyl-1,1′-biphenyl-4,4′-diamine (α-NPD) monolayer on Ag(111). At the first HATCN deposition steps (∼1 monolayer), the sample work function increases by 1.05 eV and the hole injection barrier (HIB) in the pre-adsorbed α-NPD monolayer is lowered by 0.65 eV. This results from HATCN diffusion to the silver surface through the α-NPD monolayer. Furthermore, this HATCN monolayer is proposed to form a compact chemisorbed monolayer, with a different structural arrangement than that observed on pristine Ag(111). In a second step, the additional deposited HATCN start growing on top of the α-NPD layer, and Fermi-level pinning, associated with the formation of HATCN negative polarons, is identified at the HATCN/α-NPD interface. Finally, HATCN is deposited on a α-NPD multilayer film. In this case, HATCN is also found to diffuse to the silver surface giving a similar HIB value in the α-NPD multilayer. This work demonstrates the importance of studying in detail the formation of organic heterostructures to understand the interplay between growth mode and electronic properties. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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