The implementation of inkjet-printed conductive copper in solution-processed electronics (Conference Presentation)

Through the use of solution‐based materials, the field of printed electronics has not only made new devices accessible, but enabled the process of manufacture to move towards a high-throughput industrial scale. However, while the solution‐based active layer materials employed in these types of systems have been studied quite intensely, the conducting structures that feature in printed circuits, RFID applications, logic systems and electrodes in optoelectronic devices have not received as much attention. Inkjet-printing in particular, as an additive, upscalable, direct write technique that requires no masks or lithographic pre-patterning of substrates, has been utilized to produce such structures in a wide variety of (opto)electronics, paving the way to fully solution-processed devices. However, for full compatibility with flexible, low cost substrates, the processing conditions of the deposited structures need to be controlled. This contribution highlights our work on utilizing inkjet-printing to deposit copper nanoparticles (CuNPs) in order to form conducting structures within a range of electronic applications, specifically optoelectronic devices and printed circuits, and discusses methods to improve the conductive and interfacial properties. A reductive sintering approach is presented as an alternative to commonly used laser or flash lamp curing techniques. The findings presented address the importance of continuing work in improving the effectiveness of printed conductive structures, including in their use in organic and hybrid (opto)electronic devices, in order to move towards fully solution-processed and flexible electronics.