Yang Wendong, Guo Zihao, Zhao Xun, Zhang Xiaoyuan, List-Kratochvil Emil J W
School of Electronic and Information Engineering, Liaoning Technical University, Huludao City 125105, China.
Institut für Physik, Institut für Chemie, IRIS Adlershof, Humboldt-Universität zu Berlin, Berlin 12489, Germany.
Langmuir. 2024 Apr 2;40(13):7095-7105. doi: 10.1021/acs.langmuir.4c00221. Epub 2024 Mar 21.
Conductive inks are one of the most important functional materials for printed flexible electronic devices, and their properties determine the methods of subsequent patterning and metallization. In comparison with copper nanoparticle or nanowire inks, copper particle-free inks employing copper(II) formate (Cuf) as a precursor have attracted the interest of researchers due to their flexibility in preparation, excellent stability, and lower conversion temperature. Alkanolamines can provide Cuf with excellent solubility in alcohols while being less toxic and having a certain reducibility, making them preferable ligands in comparison with aliphatic amines and pyridine. However, there have been few studies on the effects of the alkanolamine types on the performance of Cuf inks. Also, the decomposition mechanism of copper-alkanolamine complex inks is not clear. In this work, different kinds of alkanolamines were chosen as ligands to formulate Cuf inks to address the mentioned issues. The influences of amine types on the stability, wettability, thermal decomposition behavior, and electrical performance of the formulated Cuf particle-free inks were investigated in detail. The results show that the utilization of alkanolamines could provide Cuf with excellent solubility in alcohols, resulting in an ink with good stability and favorable wetting properties. The thermal decomposition temperature and electrical performance of the formulated copper ink are largely dependent on the amine used. When amines with a longer carbon chain and more branches were utilized to prepare the ink, a decreased decomposition temperature was observed on the derived inks because of the steric hindrance effect. Copper films with good morphology and conductivity could be obtained at low temperatures by selecting the appropriate alkanolamine. Copper particle-free conductive ink from 2-amino-2-methyl-1-propanol demonstrated better morphology and electrical performance (16.09 μΩ·cm) and was successfully used for conductive circuits by direct-writing.
导电油墨是印刷柔性电子器件最重要的功能材料之一，其性能决定了后续图案化和金属化的方法。与铜纳米颗粒或纳米线油墨相比，以甲酸铜（Cuf）为前驱体的无铜颗粒油墨因其制备灵活性、优异稳定性和较低转化温度而吸引了研究人员的兴趣。链烷醇胺能使Cuf在醇类中具有优异的溶解性，同时毒性较小且具有一定的还原性，与脂肪胺和吡啶相比，使其成为更优的配体。然而，关于链烷醇胺类型对Cuf油墨性能影响的研究很少。此外，铜-链烷醇胺复合油墨的分解机理尚不清楚。在本工作中，选择不同种类的链烷醇胺作为配体来配制Cuf油墨以解决上述问题。详细研究了胺类型对所配制的无Cuf颗粒油墨的稳定性、润湿性、热分解行为和电性能的影响。结果表明，使用链烷醇胺可使Cuf在醇类中具有优异的溶解性，从而得到具有良好稳定性和有利润湿性的油墨。所配制的铜油墨的热分解温度和电性能在很大程度上取决于所使用的胺。当使用具有更长碳链和更多支链的胺来制备油墨时，由于空间位阻效应，所得到的油墨分解温度降低。通过选择合适的链烷醇胺，可在低温下获得具有良好形貌和导电性的铜膜。由2-氨基-2-甲基-1-丙醇制备的无铜颗粒导电油墨表现出更好的形貌和电性能（16.09μΩ·cm），并通过直接书写成功用于导电电路。
