Patterning of High-Viscosity Silver Paste by an Electrohydrodynamic-Jet Printer for Use in TFT Applications

Electrohydrodynamic (EHD) jet printing has a variety of benefits compared to conventional inkjet techniques, such as high resolution and the ability to work with high-viscosity pastes. In this work, Ag nanoparticles with 4000 cPs were chosen because they are printable on various substrates for electronic devices. The effects of additive on the high-viscosity Ag paste formulation were investigated, and pattern lines narrower than 100 μm were achieved by EHD-jet printing with an average sheet resistance of 0.027 Ω □(−1). Furthermore, solution-processed oxide TFTs were fabricated with EHD jet-printed Ag electrodes for the first time. The electrical properties obtained were a current ratio of 1.5 × 10(6), a mobility of approximately 1 cm(2) V(−1) s(−1), a threshold voltage of 21.5 V, and a subthreshold slope of 3.05 V dec(−1).