The size of electron-hole pairs in pi conjugated systems

Abstract

We have performed momentum dependent electron energy-loss studies of the electronic excitations in sexithiophene and compared the results to those from parent oligomers. Our experiment probes the dynamic structure factor S(q,omega)and we show that the momentum dependent intensity variation of the excitations observed can be used to extract the size of the electron-hole pair created in the excitation process. The extension of the electron-hole pairs along the molecules is comparable to the length of the molecules and thus maybe only limited by structural constraints. Consequently, the primary intramolecular electron-hole pairs are relatively weakly bound. We find no evidence for the formation of excitations localized on single thiophene units.

RevTex, 3 figures, to appear in Physical Review Letters

References in corpus (1)

• Identification of excitons in conjugated polymers: a density matrix renormalisation group study

Cited by in corpus (12)

• Electron Energy-Loss Spectroscopy: A versatile tool for the investigations of plasmonic excitations
• Probing exciton dispersions of freestanding monolayer WSe2 by momentum resolved electron energy loss spectroscopy
• Investigation of the dispersion and the effective masses of excitons in bulk 2H-MoS2 using transition electron energy-loss spectroscopy
• Electronic structure of undoped and potassium doped coronene investigated by electron energy-loss spectroscopy
• Exciton character in picene molecular solids
• Dynamic response and electronic structure of potassium doped picene investigated by electron energy-loss spectroscopy
• Evidence for phase formation in potassium intercalated 1,2;8,9-dibenzopentacene
• Inelastic X-Ray Scattering Study of Exciton Properties in an Organic Molecular crystal
• Low energy exciton pocket at finite momentum in tetracene molecular solids
• Semiconductor-to-Metal Transition in the Bulk of WSe2 upon Potassium Intercalation
• Composite polaron formed on surface of two-dimensional lattice system in weak coupling regime
• Electronic excitation spectrum of doped organic thin films investigated using electron energy-loss spectroscopy