Self-Assembled Patterns in Ferroelectric Polymer Thin Films: Formation and Implications

Patterned piezoelectric polymer films serve as a suitable template for exploring various applications based on the characteristic electrical and optical properties. Here, the large-area spontaneous pattern formation in relaxor terpolymer, poly(vinylidene difluoride-trifluoroethylene-chlorofluoroethelene) (P(VDF-TrFE-CFE)) films, is demonstrated using the cost-effective breath-figure technique. The experimental parameters allowed for controlling the hemispheroidal patterns, with pore dimensions varying from a few approximate to 100 nm to approximate to mm range. Due to the increased charge accumulation region, these porous structures exhibit enhanced ferroelectric and piezoelectric responses. Additionally, the refractive index contrast in the patterned structures leads to improved diffused reflection and thermal emittance. Furthermore, in the presence of guest-dye molecules, the dominant amorphous phase of the patterned films results in higher photoluminescence yield. These features enable patterned films for high-efficiency piezoelectric generators and passive daytime radiators.