Piezoelectric transducers on curved dispersive bending wave and poke-charged touch screens

Ferroelectric thin films of lead zirconate titanate Pb(Zr _0.52,Ti_0.48)O₃(PZT) and bismuth titanate Bi₄Ti₃O₁₂(BiT) were prepared by photochemical metal-organic deposition as electromechanical transducers used in optoelectronic devices. Both solutions were deposited on flat and convex amorphous glass substrates to poke-charge the device or detect the touch point coordinate on new generation of free-shaped screens. The effects of optimization on UV exposure, precursor type and annealing temperature (600-800 °C) were investigated on microstructural, optical and ferroelectric properties of deposited thin films. Suppressing the non-uniformity of the film thicknesses due to repetitive deposition, actually there is no structural difference between the two types of substrates and their effects on the film properties. Polarization-voltage hysteresis loops showed relatively larger remnant polarization of P_r = 9.3 μC/cm² and 6.1 μC/cm² for optimized UV-irradiated PZT and BiT thin films, respectively, than uncured samples.