Preparation of electrically conductive copper films at low temperature was carried out by thermal decomposition in a nitrogen atmosphere using complexes of copper formate and various amines. Calcined films consisting of copper nanoparticles showed electrical conductivity. The conductivity and the size of the nanoparticles were dependent on the types of amines and their alkyl chain lengths. The film prepared using octylamine showed low resistivity, and the particle size was relatively small. The film prepared using dibutylamine consisted of large nanoparticles, although the resistivity was high. Blended amines of octylamine and dibutylamine produced lower resistivity in the prepared film-with the lowest resistivity of 5.0 x 10(-6) Omega cm achieved by calcination at 140 degrees C. (C) 2012 Elsevier Ltd. All rights reserved.