Piezoelectricity of picosecond laser-synthesized perovskite BaTiO₃ nanoparticles

Flexible energy harvesters based on piezoelectric nanomaterials have attracted great attention because they enable a self-powered system that converts electric energy from ambient energy resources. To achieve perovskite-structured piezoelectric nanopowders, most studies have utilized multi-step chemical-based hydrothermal reaction with repeat purification processes, which results in time-consuming production, low-yield production, and the inevitable existence of second phase. As an alternative that addresses the drawbacks of previous synthesis methods, the ultrafast laser processing based on cold ablation is highly promising for nanomaterial synthesis. In this work, we investigated the feasibility of synthesizing BaTiO₃ nanoparticles by the picosecond laser ablation of a bulk BaTiO₃ target in an ethanol solvent. The picosecond laser-synthesized BaTiO₃ nanoparticles have a spherical shape with a size of ~300 nm and typical perovskite crystallinity with tetragonal phase. To investigate the piezoelectric response from BaTiO₃ nanoparticles, we used a piezoresponse force microscope and confirmed the piezoelectric charge constant of ~130 pm⋅V⁻¹. The results indicate the viability of synthesizing piezoelectric ceramic nanoparticles by the laser ablation of a bulk target in a liquid environment.