TY  - JOUR
AU  - Nakayama, Yasuo
AU  - Bocquet, François C.
AU  - Tsuruta, Ryohei
AU  - Soubatch, Serguei
AU  - Tautz, F. Stefan
TI  - Anisotropic dispersion of excitonic bands of the single-crystal pentacene (001) surface as measured by low-energy angle-resolved high-resolution electron energy-loss spectroscopy
JO  - Journal of electron spectroscopy and related phenomena
VL  - 279
SN  - 0368-2048
CY  - New York, NY [u.a.]
PB  - Elsevier
M1  - FZJ-2025-01649
SP  - 147514
PY  - 2025
AB  - Low-energy high-resolution electron energy-loss spectroscopy (HREELS) is a useful technique for the charac-terization of various excitation processes at solid surfaces. However, no successful work has been reported onmolecular single-crystal samples yet. In the present study, low-energy angle-resolved HREELS measurementswere conducted on single-crystal pentacene, an organic semiconductor. The results confirmed the excitonicbands exhibiting energy–momentum dispersion and anisotropy of these depending on the surface crystallo-graphic directions, corroborating the occurrence of exciton delocalization, contrary to the ordinary notion of theFrenkel exciton for weakly interacting van der Waals molecular solids. The present results demonstrate that low-energy angle-resolved HREELS is applicable to the precise examination of the excitonic characteristics of solid-state surfaces, even for molecular semiconductor single crystals.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:001420630000001
DO  - DOI:10.1016/j.elspec.2025.147514
UR  - https://juser.fz-juelich.de/record/1038812
ER  -