Voltage-tuned polarization control via UV light in BiFeO3 thin film on Nb–SrTiO3

BiFeO3 thin films were grown on Nb-doped SrTiO3 substrates using radio frequency magnetron sputtering and subsequently annealed to enhance their structural and ferroelectric properties. With piezoresponse force microscopy, with a width of ∼500 nm, thin films were successfully created by controlling polarization through direct current poling. Here, we found a significant reduction in polarization amplitude around 81% when the sample was irradiated under ultraviolet (UV). These results highlight the interplay between poling and UV-induced effects, which can control the ferroelectric states. This study will pave the way for promising applications in optoelectronic devices and non-volatile memory technologies.