Opto-electronic Control Domain Manipulation in Ferroelectric Oxides

Interaction between light and ferroic order parameters in nanostructures leads to new physical functionality. In this respect, the quest for opto-electronic control of energy-efficient ferroelectric materials is gaining importance for fast memory applications. Here, we explore the light-induced polarisation switching behaviour in epitaxial freestanding BaTiO₃ (46-unit cells) films on the ITO substrates. It is observed that after writing the domains with positive and negative voltage, the materials always return to their original downward polarisation state under illumination. The material also exhibits significant enhancement in the amplitude response, which is confirmed by the imaging and spectroscopy analysis under dark and illumination conditions. The freestanding BaTiO₃ film illustrates domain-switching immediately after illuminations. Notably, the domain switching time in the freestanding membrane is estimated in the sub-second region. On the other hand, the clamped film shows slow domain relaxation under illumination conditions. The molecular dynamics simulation under different electric fields also demonstrates that the domain wall motion in the freestanding film is significantly higher than in the clamped films. Overall, in this presentation, we will discuss observed photoferroelectrics outcomes of robust electric and optics control polarisation cycling of the device for neuromorphic computing.