Low-Temperature Atmospheric Pressure Plasma for Applications in Flexible and Printed Electronics

Low-temperature plasma processing of surfaces and interfaces is an interesting option for applications in flexible and printed electronics where surface cleaning, activation or functionalization are required. Plasma processing compared to more traditional chemical treatment can be significantly cheaper and faster while eliminating the need for toxic organic solvents. Printed functional coatings often contain organic moieties from solvents, binders and other additives that tune the properties of the precursor liquid. These need to be effectively removed for optimal properties of the resulting film. Plasma can provide reactive and energetic species to the surface of printed films for post-printing processing at significantly lower temperatures compared to conventional thermal annealing. In this paper, we summarize applications of low-temperature atmospheric plasma for cleaning of indium tin oxide (ITO) and fluorine-doped tin oxide (FTO) substrates for improved interface quality between the electrode and the blocking layer in perovskite solar cells. Plasma treatment in order of seconds proved as effective as a chemical treatment for an hour. We also present a way for post-deposition mineralization of mesoporous TiO2 electron transport layer for perovskite solar cells at temperatures below 70 °C compatible with temperature-sensitive substrates.