The mechanism of alkylamine-stabilized copper fine particles towards improving the electrical conductivity of copper films at low sintering temperature†
To facilitate sintering of copper particles at low temperatures and achieve excellent electrical conductivity of copper films, reducing particle size is a common method. However, strong reducing agents which are usually used for reducing the size of particles limit their application. Here we report a novel approach to obtain highly conductive copper films. Firstly, copper fine particles were prepared by a one-pot reduction reaction utilizing D-isoascorbic acid as a mild reductant. Secondly, tight connection facilitating the sintering of particles was formed by generating convex surfaces, nanorods or nanoparticles during the oxidation procedure. The mechanism of the oxidative preheating process and its effects on the conductivity were clarified. High conductivity of copper films at low temperatures can be achieved due to the critical role of the oxidative preheating process.