Piezoelectric enhancement in glass-based PZT films with sputtering and sol–gel techniques

A novel hybrid method combining radio-frequency (rf)-sputtering and sol–gel processes was developed to fabricate highly transparent Pb(Zr0.52Ti0.48)O3 (PZT) composite thin films on ITO-coated glass substrates. A composite PZT film was prepared via a two-stage method. Initially, a PZT layer with a thickness of 3.5 μm was deposited on an ITO bottom electrode via rf sputtering. Subsequently, a second PZT layer with a thickness of 1.3 μm was spin-coated onto the initial film using the sol–gel method to form the final composite structure. The results indicate that compared to the single-layer PZT film fabricated solely by rf-sputtering, the composite PZT film exhibits significantly enhanced ferroelectric, dielectric, and piezoelectric properties. Notably, the transverse piezoelectric coefficient |e31,f| reached a value of 8.6 C/m2. Both PZT film and PZT composite film had high transmittance. For haptic feedback applications, we designed a haptic device relying on a 4.8 μm-thick PZT composite film, which was deposited on a 0.5 mm-thick glass substrate. An out-of-plane displacement of 105.6 μm was achieved at an extremely low voltage of 20 Vpp(Vpeak-peak). This advancement establishes a viable pathway toward the development of low-voltage, high-displacement haptic actuators.