Fabrication of PZT-Au composite films via Aerosol Deposition for real-time tunable optical modulators

In this study, we successfully fabricated PZT-Au composite films using the Aerosol Deposition (AD) method and demonstrated their potential as real-time tunable optical modulators. By integrating gold nanoparticles into the PZT matrix, we achieved dynamic control of plasmonic absorption and optical modulation under applied electric fields. The AD method enabled room-temperature deposition of dense films with uniformly distributed Au nanoparticles. Post-annealing, the Au particles recovered their spherical shape, enhancing plasmonic absorption and improving optical transparency. A relative transmittance change of 41 % at 780 nm was observed when increasing the voltage from 30 V to 150 V, along with a 50 nm redshift attributed to electric-field-induced refractive index changes in the PZT matrix. Furthermore, under a 10 MHz alternating electric field, the films exhibited periodic modulation of transmittance, confirming their capability for high-speed, real-time optical response. These results demonstrate the promise of PZT-Au composites for next-generation tunable electro-optic devices and sensors.