The search for sustainable and efficient energy conversion technologies is becoming increasingly critical in response to global energy and environmental challenges. Traditional lead-based piezoelectric materials, such as lead zirconate titanate (PZT), have high piezoelectric constant but present significant health problems and environmental risks due to their hazardous metal contaminants. This study addresses these concerns by investigating barium titanate (BTO), a lead-free alternative, and enhancing its performance using anisotropic nanowires (NWs) structures. BTO NWs were synthesized via a two-step hydrothermal method and incorporated into a poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] matrix to fabricate a piezoelectric composite film. The resulting device demonstrated a notable increase in electrical output compared to devices based on isotropic morphology of BTO nanoparticles, exhibiting enhanced performance. These findings suggest that BTO NWs hold significant promise for applications in flexible and wearable electronics, paving the way for further advancements in sustainable energy technology.

The Hall factor in a two-dimensional device with indirect conduction valleys is calculated for several growth on various strain conditions. In the [001] or [111] growth direction, the two-dimensional constant energy surfaces of occupied valleys are shown to be isotropic ally distributed. However, in the [110] growth direction, the distribution of occupied valleys on the plane is not isotropic. This fact is the reason for the anisotropic Hall factor on the sample plane.