Piezoelectric inverse opal BaTiO3 films using one-drop spin-coated polystyrene-polydimethylsiloxane particle array templates

Abstract

In this study, as an effective piezoelectric network structure, barium titanate (BaTiO3) inverse opal films were developed using well-ordered polystyrene-polydimethylsiloxane (PS-PDMS) particle array templates. In order to develop the particle array templates, colloidal solution concentration and solvent drying temperature were simultaneously investigated to achieve an optimal condition during post thermal treatment after one-drop spin-coating. The PS-PDMS particle array templates exhibited a maximum hexagonal pattern of 3475 μm2 and a thickness of 75 ± 10 μm owing to sufficient colloidal particle movement (by Brownian motion) and capillary force (by solvent evaporation) induced during the post thermal treatment process. The piezoelectric inverse opal BaTiO3 films were obtained via sol-gel synthesis of BaTiO3 precursors in the PS-PDMS particle array templates. After calcination at 600 °C, clear perovskite crystal structure (ABO3) was confirmed from the inverse opal films, which can provide a sufficient piezoelectric property from the sponge-like three-dimensional network structure. Further, the one-drop spin-coating method with post thermal treatment could be a feasible approach for the facile preparation of thick particle array templates for various applications such as solar cells, piezoelectric energy harvesters, and chemical sensors.