Multilayer structures of the charge transfer complex (N-octadecylpyridinium)-Ni(dmit)2 have been deposited by the Langmuir-Blodgett technique onto substrates of gold-coated glass and silicon with a thermally grown overlayer of silicon dioxide. Capacitance measurements have revealed values of relative permittivity of 3.2 and 6.3 for the dmit layers in the as-deposited state and after iodine doping respectively. Thin film transistor structures have been built up incorporating the dmit complex as the semiconducting layer. Modulation and saturation of a current flowing between source and drain by a voltage applied to the gate has been observed. The mobilities of the charge carriers in the dmit layers have been calculated as 2.4 x 10(-5) cm2 V-1 s-1 in the as-deposited state and 1.8 x 10(-1) cm2 V-1 s-1 after doping with iodine.