Lead titanate thin films deposited by metallorganic chemical vapor deposition (MOCVD)

Highly transparent lead titanate (PbTiO₃) thin films were deposited on both platinum-coated silicon wafers and sapphire disks. The results were characterized using XRD (X-ray diffraction) to determine the phases present and the presence of preferred orientation. SEM (scanning electron microscopy) was used to examine the morphology of both the surface and the cross-section. UV-VIS-NIR (ultraviolet, visible, near infrared) spectrophotometry was used to determine the dispersion relationship and the optical band gap energy. XRD revealed a nonoriented film on sapphire while the film on the platinum substrate was preferably oriented in the (100) and (001) directions. A relatively dense morphology was observed using SEM. The formation of a very fine structure was also observed upon annealing the films following deposition. The refractive index was 2.474 at 632.8 nm. From this index the packing density was estimated to be about 89%