Abstract
Piezoelectric thin films are of increasing interest in low-voltage micro electromechanical systems for sensing, actuation, and energy harvesting. They also serve as model systems to study fundamental behavior in piezoelectrics. Nextgeneration technologies such as ultrasound pill cameras, flexible ultrasound arrays, and energy harvesting systems for unattended wireless sensors will all benefit from improvements in the piezoelectric properties of the films. This paper describes tailoring the composition, microstructure, orientation of thin films, and substrate choice to optimize the response. It is shown that increases in the grain size of lead-based perovskite films from 75 to 300 nm results in 40 and 20% increases in the permittivity and piezoelectric coefficients, respectively. This is accompanied by an increase in the nonlinearity in the response. Band excitation piezoresponse force microscopy was used to interrogate the nonlinearity locally. It was found that chemical solution-derived PbZr0.52Ti0.48O3 thin films show clusters of larger nonlinear response embedded in a more weakly nonlinear matrix. The scale of the clusters significantly exceeds that of the grain size, suggesting that collective motion of many domain walls contributes to the observed Rayleigh behavior in these films. Finally, it is shown that it is possible to increase the energy-harvesting figure of merit through appropriate materials choice, strong imprint, and composite connectivity patterns.
Original language | English |
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Article number | 6020846 |
Pages (from-to) | 1782-1792 |
Number of pages | 11 |
Journal | IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control |
Volume | 58 |
Issue number | 9 |
DOIs | |
State | Published - Sep 2011 |
Funding
manuscript received december 22, 2010; accepted april 5, 2011. The authors gratefully acknowledge financial support from a national security science and Engineering Faculty Fellowship, the center for dielectric studies, and the semiconductor research corporation, which supported the original research discussed in this paper. s. Trolier-mcKinstry, F. Griggio, c. yaeger, p. Jousse, d. Zhao, s. s. n. bharadwaja, and T. n. Jackson are with the materials science and Engineering department and materials research Institute, University park, pa (e-mail: [email protected]). s. Jesse and s. V. Kalinin are with The center for nanophase materials science and materials science and Technology division, oak ridge national laboratory, oak ridge, Tn.