Direct writing of silver conductive patterns: Improvement of film morphology and conductance by controlling solvent compositions

The authors have investigated the influence of conductive ink compositions on the quality of ink-jet printed patterns. Controlling the solvent compositions plays an important role of reducing the so-called coffee ring effect. The use of a higher boiling point solvent with lower surface tension such as ethylene glycol enables the formation of a uniform deposit of silver nanoparticles due to surface tension gradient-induced inward Marangoni flow, which can compensate outward convective flow. It is demonstrated that the ink-jet printed film quality is directly related to the resistance difference in the conductive patterns.