Low-temperature sintering of highly conductive silver ink for flexible electronics

Abstract

Herein, we report a naive synthesis procedure for the development of a durable, particle-free, low-temperature sintered silver organic precursor (SOP) ink using low boiling point mild organic complexing ligands. The synthesized inks were printed on variable substrates such as glass, PET and PI using spin-coating and nozzle-jet printing methods. The as-printed films were sintered at low temperatures (<90 °C) to give smooth silver films with excellent adhesion and high conductivity. The SOP spin-coated film on glass annealed at 60 °C and the nozzle-jet printed film on PET sintered at 75 °C yielded high conductivities of 1.07 × 10⁶ S m⁻¹ and 2.74 × 10⁶ S m⁻¹, respectively, which are only one-order-of-magnitude lower than bulk silver (∼10⁷ S m⁻¹). The silver films connected with light-emitting diodes (LEDs) also showed excellent adhesion strength through the bending and twisting test.