Fabrication and Characterization of the Transparent PLZT-Based Piezoelectric Speaker

The transparent piezoelectric loudspeaker has received significant attention as acoustic components for smart window system due to its lightweight, portability, and visibility. In this work, we fabricated a Lanthanum lead zirconate titanate (PLZT) ceramic disc with transparency (65% at 550 nm) and piezoelectric properties (d33 = 180 pC/N) by oxygen atmosphere sintering method. In addition, a transparent piezoelectric loudspeaker was developed by sputtering top and bottom electrode with indium tin oxide (ITO) thin film on the PLZT ceramic disc, and attaching them to Polyethylene terephthalate (PET) as a diaphragm. Applying the input voltage of 10 V
pp
, the piezoelectric PLZT loudspeaker shows a frequency response of 30 to 68 dB sound pressure in the frequency range of 500 Hz to 8 kHz. This study showed that the transparent PLZT speakers could potentially be applied to future smart devices or displays.