In Situ Local Oxidation of SnO Induced by Laser Irradiation: A Stability Study

In this work, semiconductor tin oxide (II) (SnO) nanoparticles and plates were synthesized at room conditions via a hydrolysis procedure. X-ray diffraction (XRD) and transmission electron microscopy (TEM) confirmed the high crystallinity of the as-synthesized romarchite SnO nanoparticles with dimensions ranging from 5 to 16 nm. The stability of the initial SnO and the controlled oxidation to SnO(2) was studied based on either thermal treatments or controlled laser irradiation using a UV and a red laser in a confocal microscope. Thermal treatments induced the oxidation from SnO to SnO(2) without formation of intermediate SnO(x), as confirmed by thermodiffraction measurements, while by using UV or red laser irradiation the transition from SnO to SnO(2) was controlled, assisted by formation of intermediate Sn(3)O(4), as confirmed by Raman spectroscopy. Photoluminescence and Raman spectroscopy as a function of the laser excitation source, the laser power density, and the irradiation duration were analyzed in order to gain insights in the formation of SnO(2) from SnO. Finally, a tailored spatial SnO/SnO(2) micropatterning was achieved by controlled laser irradiation with potential applicability in optoelectronics and sensing devices.