Low-defect CeO2 films synthesis by combined spray pyrolysis using different precursors

Abstract

CeO 2 films were fabricated by combining both a modified spray pyrolysis and the vapour transport deposition techniques. Two different precursors, cerium chloride and cerium acetate, were explored. In our approach, the pyrolytic process was not concomitant with the spray deposition and the introduction of the vapour transport condition has showed to improve both the morphological and optical quality of the films. Samples obtained from cerium chloride show a porous morphology, usual for polycrystalline CeO 2 layers, and a homogeneous light emission. When using vapour transport during thermal treatment, we achieved an enhanced luminescence, blue shifted to 3.08 eV and with negligible presence of defect bands. Films obtained from cerium acetate present similar crystalline properties, and a more defined light emission line shape, also peaked at 3.08 eV but with even lower contribution from known green-red defect bands. These results show that the proposed combined technique leads to CeO 2 films with homogeneous, enhanced optical properties.