Exothermic and Recursive Reaction of Self-Sinterable Silver Ink for Flexible Electronics

Abstract

For the construction of highly conductive printed electrodes on a polymeric substrate with a low glass transition temperature, the development of a low temperature sinterable conductive ink has been a crucial issue in printed electronics and display applications. In this work, we introduce a novel type of self-sinterable silver ink, whose sintering is triggered at a low temperature and completed with the aid of its own exothermic reaction, and propose its exothermic reaction mechanism. Although individual components of this self-sinterable silver ink, Ag₂O and silver carboxylate, exhibit endothermic behaviors, their mixture form shows a strong exothermic reaction when heated at 150 °C. It is found that the dissociated form of the used silver carboxylate contributes to the reduction of Ag₂O to Ag through its recursive reaction and produces silver nanoparticles. The major source of an exothermic reaction results from the nucleation and fusion of silver nanoparticles.