Chemical sintering of Ag nanoparticle conductive inks at room temperature for printable electronics

Alternative Sintering Processes and Their Influence on the Electrical Resistance of Printed Ag Nanoparticle Conductive Networks

“…Moreover, UV sintering might not achieve the same level of conductivity as other sintering techniques due to less effective particle coalescence and densification . Vacuum sintering allows the evaporation of insulating organics under vacuum at room or moderately elevated temperatures. , This technique can aid in the densification of particles by accelerating the removal of ink solvent and trapped gas bubbles within conductive structures, which might otherwise inhibit particle connectivity. , In addition, various chemical species, such as hydrochloric acid (HCl), acetic acid (CH 3 COOH), and even water vapor (H 2 O), have shown the capability to sinter metal NPs and improve electrical conductivity. ,− Despite significant efforts by the aforementioned sintering studies, a detailed comparison of their effects in the scope of printed electronics, such as the printing of conductive patterns or circuits, is still lacking. Moreover, their environmental impact, including potential energy costs, remains not fully understood.…”

Low-Temperature Self-Stacking Ink for Electrohydrodynamic Direct Writing

“…However, due to the presence of Ag 2 O nano-particles, the ink had strong photosensitivity, which required avoiding exposure to light during storage; otherwise, the metal particles would aggregate, leading to nozzle blockage. Rezaga and Balela used silver acetate (CH 3 COOAg) and ascorbic acid (C 6 H 8 O 6 ) as silver precursors and reducing agents, respectively. Polyacrylic acid (PAA) and sodium polyacrylate (PAA-Na) were used as stabilizers or end-capping agents to prepare ink, which was mixed with a halide solution and sintered at room temperature, thus possessing the advantage of low-temperature sintering.…”

Silver–Copper Alloy Nanoinks for Ambient Temperature Sintering

“…Some reports showed that Ag NPs and nanowires exhibit room temperature sintering properties in the presence of electrolytic halides. 16,17 For example, AgCu core−shell NPs synthesized under organic conditions were sintered at room temperature utilizing a reducing agent like hydrazine. In other methods, the room temperature sintering involved galvanic displacement and subsequent electrolytic conditions.…”

“…On the other hand, the process of reverse Ostwald ripening occurs when smaller particles break away from the NCs, which can lead to a bimodal distribution of NCs/NPs . Different methods such as wet chemical and physical methods have been demonstrated for the synthesis, − but most of the methods require organic solvents and high temperature. The NPs synthesized in aqueous solution or low temperatures often suffer from instability due to the propensity of aggregations.…”

“…There have been limited reports on the ability of near-room temperature sintering for silver-based nanoinks or nanopastes. Some reports showed that Ag NPs and nanowires exhibit room temperature sintering properties in the presence of electrolytic halides. , For example, AgCu core–shell NPs synthesized under organic conditions were sintered at room temperature utilizing a reducing agent like hydrazine. In other methods, the room temperature sintering involved galvanic displacement and subsequent electrolytic conditions. , We report herein a new approach to scalable synthesis of silver–copper (AgCu) alloy NPs and nanoinks with room temperature sintering capability.…”