Ponente
Descripción
In recent years, it has been found that ferroelectric materials have photosensitive and photovoltaic properties, potentially useful for solar energy recovery applications. In this regard, BiFeO3 is a material that exhibits excellent ferroelectric properties, a bandgap in the visible range, and a high Curie temperature. The BiFeO3 thin film systems doped with nickel at 2%, 4%, and 6% (atomic percentage) were investigated. These films were synthesized using sol-gel and spin coating techniques, and then thermally treated at 550°C with post-treatment under an oxygen flow for 30 and 60 minutes at 550°C too. Using XRD, a R3c rhombohedral phase without notable secondary phases was obtained. Rietveld refinement using MAUD software determined that the crystal size decreases as the amount of nickel increases. SEM analysis showed that the grain size decreases as the nickel content increases, while post-treatment favors an increase in grain size over time. In most cases, ferroelectric analysis yielded curves with high leakage current. However, using AFM, the ferroelectric domain recorded was observed. Reflection-Transmission measurements were used to determine the bandgap, which showed a slight increase with increasing nickel content and post-thermal treatment time. Finally, using current-voltage measurements, a slight photoresponse in the UV-VIS range was determined.
