Importance of the Heat Treatment Scheme on Self-Reducing Reactive Silver Inks

作者：Steven DiGregorio, Subbarao Raikar, Owen Hildreth · 发表于：ACS Applied Electronic Materials · 年份：2023 · DOI：10.1021/acsaelm.3c01082 · 被引用次数：9 · 研究领域：Nanomaterials and Printing Technologies、Advanced Sensor and Energy Harvesting Materials、Additive Manufacturing and 3D Printing Technologies

Self-reducing reactive silver inks can print high-quality silver at reasonable temperatures. While numerous studies have explored the impact of processing temperature on electrical properties, the role of the heat treatment scheme has not yet been studied. Common heat treatment schemes include printing and drying inks at room temperature before heat treatment, performing heat treatments while the inks are still wet, and directly printing the inks onto heated substrates. Each scheme generates distinct heat transfer and mass transport kinetics that can affect the silver morphology and electrical properties. However, to date, the impact of different schemes has not been systematically investigated. To address this knowledge gap, this work investigates how different heat treatment schemes impact metal formation, sintering, and the resultant electrical properties of printed self-reducing reactive silver inks. Heat treatment on room-temperature dried inks and wet inks, with top-down (oven) and bottom-up (hot plate) heating sources, were compared. Inks dried at room temperature resulted in extremely porous films that required high heat treatment temperatures (>100 °C) for silver densification. However, these dried films could only densify locally, and their high initial porosities resulted in voids and high resistances (∼0.6 Ω mm –1 ) even after heat treatments above 300 °C. Inks that were wet during heat treatment showed moderate improvements in electrical properties with resistanc...