Understanding Switching in Hexagonal Ferroelectrics by Combining Large-scale Reactive MD and Experiments

The recent discovery of multi-functional properties such as ferroelectricity in the hexagonal nitride and oxide materials has generated renewed interest in them, due to their compatibility with existing CMOS integration. These materials have high durability, large band gaps and possess tunable optical and piezoelectric properties by doping. Yet, the origin of ferroelectricity, and its switching mechanism under electric-fields remain unclear, making it difficult to design improved hexagonal ferroelectrics that can switch at lower coercive fields to enable low-power microelectronic devices. We have performed large-scale simulations (> 60K atoms) of field-induced switching of wurtzite-ZnO using reactive force-fields and analyzed the trajectory along the hysteresis loop using novel data analytics to unravel the switching mechanism. In this talk, we will present the atomistic switching mechanism, extract relevant energy-barriers for switching and additional insights from our analysis, and compare with available experiments to validate our findings.