Towards a Large-Area Freestanding Single-Crystal Ferroelectric BaTiO3 Membrane

The fabrication and transfer of freestanding single-crystal ferroelectric membranes deserve intensive investigations as to their potential applications in flexible wearable devices, such as flexible data storage devices and varied sensors in E-skin configurations. In this report, we have shown a comprehensive study approach to the acquisition of a large-area freestanding single-crystal ferroelectric BaTiO3by the Sr3Al2O6scarification layer method. By controlling the thickness of the BaTiO3and Sr3Al2O6, the exposed area of the Sr3Al2O6interlayer, and the utilization of an additional electrode La2/3Sr1/3MnO3layer, the crack density on the freestanding BaTiO3can be dramatically decreased from 24.53% to almost none; then, a more than 700 × 530 μm2area high-quality freestanding BaTiO3membrane can be achieved. Our results offer a clear and repeatable technology routine for the acquisition of a flexible large-area ferroelectric membrane, which should be instructive to other transition metal oxides as well. Our study can confidently boost flexible device fabrication based on single-crystal transition metal oxides.Keywords:crack density;ferroelectrics;freestanding;single crystal