Advance engineered piezoelectric materials for energy harvesting devices

Piezoelectric materials offer a number of advantages in energy harvesting systems, by transforming ambient vibration into electrical energy, which can be stored and power other devices. To improve energy harvesting device performance, the figure of merit (e312/ ) is vital to achieve a higher piezoelectric voltage and maximum the power output. In this study, Pb(Zr1-xTix)O3 (PZT) was chosen for its prime piezoelectric properties, such as their high piezoelectric coefficients, high power output density and relatively low epsilon.
Epitaxial PZT thin films with controlled orientations are achieved on silicon substrates by pulsed laser deposition (PLD). Pb(Zr1-xTix)O3 thin films with variety of dielectric constant () and piezoelectric coefficient (e31, d33), were studied and compared with each other. We found very large figure of merit values within these engineered piezoelectric thin films. Using optimized composition, crystal orientation and strain, maximum values of 20.4 3 C/m2 were found.. A shift of morphotropic phase boundary (MPB) is observed in the perovskite thin film structure, which is due to the residual strain caused by the
different thermal expansion coefficients between PZT thin films and silicon substrates.
These results show that for epitaxial PZT thin films, the composition of the PZT should be optimized to compensate the strain state. Besides the characterization of material properties, energy harvesting devices are also being fabricated and will be discussed in the contribution.