Transparent piezoelectric thin-film devices: Pb(Zr, Ti)O3 thin films on glass substrates

Abstract

To realize transparent piezoelectric microdevices, Pb(Zr,Ti)O3 (PZT) thin films are deposited on fluorine-doped tin oxide (FTO)-coated glass substrates, and the resultant piezoelectric properties are evaluated. PZT thin-film deposition is conducted by radio frequency (RF) magnetron sputtering and sol-gel methods. X-ray diffraction (XRD) measurements indicate that both sputtering and sol-gel PZT thin films on FTO-coated glass exhibit a polycrystalline perovskite structure with sufficient transparency. The relative dielectric constant and dielectric loss for the PZT thin films are 344 and 3.3 % for sputtering and 482 and 8.2 % for sol-gel deposition, respectively. In addition, the PZT thin films exhibit typical ferroelectric P–E hysteresis curves. The converse piezoelectric coefficient is measured from the tip displacement of the transparent unimorph cantilevers composed of PZT thin films on glass substrates. The sputtering and sol-gel depositions both produce transparent PZT thin-film devices with a clear converse piezoelectric effect, the converse piezoelectric coefficient |e31,f| of which ranges between 2.8 and 5.0 C/m2.