Insights on enhancing the adhesion of inkjet-printed europium-doped yttrium oxide by tailoring interfacial bonding environments

• Nitrate precursors offer an accessible and scalable path for oxide deposition. • A droplet spacing of 220 µm can conceal luminescent printed QR code patterns. • Cation diffusion and thermal mismatch affect bonding in Eu:Y 2 O 3 films on SS 304. • Sodium diffusion to the film/glass interface can negatively impact film adhesion. • XRD, PL, UV–Vis, and XPS showed 350 °C didn’t form oxide, while 450–550 °C did. Inkjet printing of metal nitrate precursors and subsequent annealing offers a facile and scalable route toward tailoring metal oxides in well-defined patterns. In the following work, an ink formulation comprised of yttrium nitrate hexahydrate, europium nitrate hexahydrate, and urea was printed onto borosilicate glass and stainless steel 304 substrates to study the surface reaction and interface evolution after annealing in an air or N 2 environment. A QR code was fabricated with luminescent europium-doped yttrium oxide droplets to demonstrate the user-defined patterning capability of the inkjet printing technique, in which an invisible pattern to the naked eye was achieved for the oxide deposited on stainless steel. X-ray photoelectron spectroscopy reveals the reaction evolution from the yttrium nitrate precursor to yttrium oxide and yields insight into the potential role of cation diffusion and thermal expansion mismatch in governing the adhesion properties of the oxide layer.