Electronic structure and interface properties of a model molecule for organic solar cells.
We study the electronic structure of 4,7-bis(5-methylthiophen-2-yl)benzo[c][1,2,5]thiadiazole (MTBT) and its interface properties with gold using X-ray photoemission spectroscopy (XPS), valence-band ultraviolet photoemission spectroscopy (UPS), X-ray absorption spectroscopy (XAS), as well as resonant photoemission (ResPES). MTBT can be regarded as a model molecule for PCPDTBT, a promising candidate for efficient bulk heterojunction solar cells. Almost no contribution of sulfur and only a weak contribution of nitrogen to the HOMO level is found. At the interface with gold, a strong chemical interaction between the sulfur of the benzothiadiazole and gold occurs, which may have consequences for interface properties in devices.
Hintz
Holger
H
Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 8, 72076 Tübingen, Germany.
Peisert
Heiko
H
Aygül
Umut
U
Latteyer
Florian
F
Biswas
Indro
I
Nagel
Peter
P
Merz
Michael
M
Schuppler
Stefan
S
Breusov
Dietrich
D
Allard
Sybille
S
Scherf
Ullrich
U
Chassé
Thomas
T