Molecular-assembly nanostructures of 1:1 mixed Langmuir|Blodgett films
of amphiphilic bis-TTF macrocycle and F4-TCNQ

Yoko Tatewaki, Tomoyuki Akutagawa, Takayoshi Nakamura,
Hiroyuki Hasegawa, Shinro Mashiko, Christian A. Christensen, Jan Becher

Langmuir|Blodgett (LB) films of 1:1 mixture between an electron donor of amphiphilic bis-tetrathiafulvalene (TTF) macrocycle (1) and an electron acceptor of 2,3,5,6-tetrafluoro-7,7,8,8-tetracyano-p-quinodimethane (F4-TCNQ) were fabricated on substrate surface. Formation of molecular-assembly nanowires was observed on mica surface, whose typical dimension was 3 nm (height) ~ 50 nm (width) ~ 1000 nm (length). The one-dimensional nanowires were composed of completely charge-transferred (12+)(F4-TCNQ|)2, which coexisted with two-dimensional domains of nanowire bundles of neutral 10. Room temperature electrical conductivity of 20-layer LB film for 1:1 mixed monolayer of 1 and F4-TCNQ was 8.3 ~ 10|4 S cm|1. The film showed a semiconducting temperature dependence with an activation energy of 0.30 eV, which was 0.1 eV larger than that of (12+)(F4-TCNQ|)2 LB film.