3D nonlinear photolithography of Tin oxide ceramics via femtosecond laser

As a wide band gap semiconductor material, tin oxide (SnO2) has been widely used in gas sensing, optoelectronics and catalysis. The complex micro and nanoscale three-dimensional (3D) geometric structures endow the conventional SnO2 ceramics with novel properties and functionalities. Nevertheless, ceramics cannot be cast or machined easily due to their high mechanical toughness and resistance. The additive manufacturing opens a great opportunity for flexibly geometrical shaping, while the arbitrary shaping of SnO2 ceramics at micro and nanoscale is always a challenge. Herein, preceramic monomers which can be polymerized under ultrafast laser irradiation, were utilized to form complex and arbitrary 3D preceramic polymer structures. After calcination treatment, these green-body structures could be converted into pure high-dense SnO2 ceramics with uniform shrinkage, and the feature size was down to submicron. Transmission electron microscopy (TEM) analysis displays that the printed SnO2 ceramic nanostructures can be nanocrystallized with grain sizes of 2.5 ± 0.4 nm. This work provides the possibility of manufacturing 3D SnO2 ceramic nanostructures arbitrarily with sub-100 nm resolution, thus making it promising for the applications of SnO2 in different fields.