Enhanced piezoelectric properties of (110)-oriented PbZr1−xTixO3 epitaxial thin films on silicon substrates at shifted morphotropic phase boundary

Piezoelectrical, ferroelectrical, and structural properties of epitaxial pseudocubic (110)pc oriented 500 nm thick PbZr1−xTixO3 thin films, prepared by pulsed laser deposition on (001) silicon substrates, were measured as a function of composition. The dependence of the measurement data on the Ti content is explained by an abrupt transition from the rhombohedral r-phase to the tetragonal (c/a) 45 phase for x  ≈  0.6, indicating a shift of the Morphotropic Phase Boundary to this value, where the effective piezoelectric coefficient e3 1 ,eff and dielectric constant ε33 ,eff reach their maximum values. These findings are of great significance for Si-based piezo-micro electro mechanical systems, in particular energy harvesters. The largest value of the figure-of-merit for such devices was found for x  = 0.6, FOM=24.0 GPa