Domain control and periodic poling of epitaxial ScAlN

ScAlN is an emerging ferroelectric material that possesses large bandgap and strong piezoelectricity and holds great promises for enhanced χ ( 2 ) nonlinearity. In this study, we demonstrate high-fidelity ferroelectric domain switching and periodic poling of Al-polar ScAlN thin film epitaxially grown on a c-axis sapphire substrate using gallium nitride as a buffer layer. Uniform poling of ScAlN with periods ranging from 2 to 0.4 μm is realized. The ability to lithographically control the polarization of epitaxial ScAlN presents a critical advance for its further exploitation in ferroelectric storage and nonlinear optics applications.