15:45 〜 16:00
▲ [16p-A409-8] Compositional modification of epitaxial Pb(Zr,Ti)O3 thin films for high-performance piezoelectric energy harvesters
キーワード：Piezoelectric energy harvester, PZT, direct piezoelectric effect
To produce high-performance piezoelectric energy harvesters (PEH), piezoelectric materials with a large direct piezoelectric coefficient (e31,f) and a small relative dielectric constant (εr,33) are required. In this study, PEHs were fabricated based on epitaxial Pb(Zr,Ti)O3 (PZT) thin films. The epitaxial PZT thin films were deposited on Si substrates by an RF magnetron sputtering. The Zr/Ti ratio of the thin films was controlled by using sputtering targets with given compositions and by combining targets with different compositions. Meanwhile, the direct e31,f values were evaluated by an unimorph cantilever method which is also applicable to the assessment of PEHs’ performances. The PZT cantilever of Zr/Ti = 58/42 exhibited a direct e31,f of 10.4 C/m2, along with a εr,33 of 285. According to the figure of merit (FOM) defined as (e31,f)2/ε0εr,33, the PZT cantilever had a value of 43 GPa. Moreover, at a resonant frequency of 421 Hz under an acceleration of 11 m/s2, the PZT cantilever presented a high output power of 158.0 µW, which is very promising for the high-performance PEH applications.