SKM 2023 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 10: Organic Molecules on Inorganic Substrates II: Electronic, Optical and Other Properties II
O 10.7: Vortrag
Montag, 27. März 2023, 16:45–17:00, CHE 89
Influence of N-introduction in pentacene on the electronic structure — •Mohsen Ajdari1, Marvin Hoffmann2, Felix Landwehr1, Olena Tverskoy3, Uwe H. F. Bunz3, Andreas Dreuw2, and Petra Tegeder1 — 1Physikalisch-Chemisches Institut — 2Interdisziplinäres Zentrum für Wissenschaftliches Rechnen — 3Organisch-Chemisches Institut, Universität Heidelberg
Organic electron-transporting (n-channel) semiconductors such as N-heteropolycyclic aromatic compounds are of great interest for use in a variety of (opto)electronic applications.
In this study, vibrational and electronic high-resolution electron energy loss spectroscopy (HREELS) in combination with quantum-chemical calculations are utilized to investigate the influence of N- introduction on the adsorption geometry and electronic structure of two pentacene derivatives, namely 6,13-diazapentacene (DAP) and 6,7,12,13-tetraazapentacene (TAP) on Au(111).
Our findings indicate that in comparison to parent pentacene (PEN), introduction of nitrogen atoms in the aromatic backbone of its aza derivatives leads to a narrowing of the optical gap (S0 → S1 transition) from 2.1 eV for PEN to 2.0 eV for DAP and to 1.6 eV for TAP as well as an increase in the first triplet state energy from 0.9 eV for PEN and DAP to 1.2 eV in TAP. Additionally, In the series PEN, DAP, and TAP, the α-band (S0 → S2 transition) gains significantly in intensity due to individual effects of the introduced nitrogen atoms on the orbital energies.