Water-Soluble Copper Ink for the Inkjet Fabrication of Flexible Electronic Components

Abstract

The aim of this work is preparation and investigation of copper conductive paths by printing with a different type of functional ink. The solutions based on copper-containing complex compounds were used as inks instead of dispersions of metal nanoparticles. Thermal characteristics of synthesized precursors were studied by thermogravimetry in an argon atmosphere. Based on the comparison of decomposition temperature, the dimethylamine complex of copper formate was found to be more suitable precursor for the formation of copper layers. Structure and performance of this compound was studied in detail by X-ray diffraction, test of wettability, printing on flexible substrate, and electrical measurements.

Key Aspects of the Processes of Thermal Decomposition of Complex Compounds of Copper Formate for Low-Temperature Printed Electronics

“…When the reaction proceeds according to the dehydration mechanism, it opens the way for additional chemical interactions between the reaction products since further interaction of ligands can take place only in the presence of water molecules . Thus, the release of heat during thermal decomposition of the EA, DEA, and Pyr samples, according to the results of XRD, is associated with a number of exothermic reactions leading to the formation of oxides normalL + normalH 2 normalO → normalL normalO normalH …”

Molecular copper decomposition ink for printable electronics

“…Another avenue for printable metal features would be to utilize molecular ink materials instead. 3,[17][18][19][20][21] Unlike the nanostructures, molecular inks do not oxidize as they start as ions (such as Cu 2+ instead of Cu 0 ). 16,22 However, typical molecular inks suffer from having low concentrations and organic volatile solvents.…”

“…In spite of these drawbacks, expanding the use of molecular inks can provide new avenues for printable electronics. 3,16,[18][19][20][21] In this study, we explore printable and air-stable molecular copper ink materials from metal-organic decomposition (MOD) by using copper ions, including both copper formate (Cu-F MOD) and aqueous copper formate amine complex materials (Cu-A MOD). The decomposition temperature of Cu-F can be reduced by complexing with amines, allowing for lower temperature compatibility with paper and polyester-based flexible electronics.…”

“…In spite of these drawbacks, expanding the use of molecular inks can provide new avenues for printable electronics. 3,16,18–21…”

Temperature-Sensing Inks Using Electrohydrodynamic Inkjet Printing Technology

“…Jang et al fabricated a transparent electrode using an Ag grid [ 17 ]. Shabanov et al studied copper inks, whose application to printing technology was difficult owing to oxidation, and produced copper inks that are capable of printing thin conductive copper wires [ 18 ]. As such, research on the application of EHD inkjet printing technology is actively underway [ 19 , 20 ].…”