PREPARATION AND CHARACTERIZATION OF CONDUCTING THIN-FILMS OF MOLECULAR ORGANIC CONDUCTORS (TTF-TCNQ)

Tetrathiafulvalene (TTF) and tetracyanoquinodimethane (TCNQ) form a ch arge-transfer complex which exhibits a high electric conductivity. In this work TTF-TCNQ thin films were prepared by CVD (chemical vapour de position) at low pressure and using TTF and TCNQ as precursors. Substr ates were common glass. These layers exhibit preferential orientation in the crystallization along the [001] direction and have a room tempe rature conductivity ranged between 6-24 Omega(-1) cm(-1). Whereas at l ow temperatures (smaller than a transition temperature T-p) they displ ay a highly resistive semiconductor-like behaviour, above T-p the cond uctivity exhibits a small effective activation energy. T-p approximate to 50-60 K is interpreted as a signature of the Peierls transition. T he evaluation of the stoichiometry was performed by UV-visible spectro scopy. The morphology and structure of the layers were also studied.