Direct liquid injection chemical vapor deposition of platinum doped cerium oxide thin films

• Pt-doped ceria were synthesized.
• Films were obtained by direct liquid injection chemical vapor deposition.
• Simultaneous deposition of Pt and Ce was used to obtain homogeneous films.
• Pt2 + was revealed through X-ray photoelectron spectroscopy.
• Different routes were used to exalt Pt2 +/Pt ratio.

Thin films of Pt-doped CeO2 were grown by direct liquid injection chemical vapor deposition on silicon wafer covered by native oxide at 400 °C using Ce(IV) alkoxide and organoplatinum(IV) as precursors. X-ray photoelectron spectra evidenced that the platinum oxidation state is linked to the deposition way. For platinum deposited on top of cerium oxide thin films previously grown, metallic platinum particles were obtained. Cerium and platinum codeposition allowed obtaining a Pt0 and Pt2 + mixture with the Pt2 + to Pt ratio strongly dependent on the platinum flow rate during the deposition. Indeed, the lower the platinum precursor flow rate is, the higher the Pt2 + to Pt ratio is. Moreover, surface and cross-sectional morphologies obtained by scanning electron microscopy evidenced porous layers in any case.