Effects of Ti-doping on energy storage properties and cycling stability of Pb_0.925La_0.05ZrO₃ antiferroelectric thin films

Pb_0.925La_0.05Zr_1-xTi_xO₃ (PLZT, x = 0.5%∼5.5%) thin film were fabricated on Pt(1 1 1)/TiO₂/SiO₂/Si substrates by sol–gel method. In the Zr-rich region, the saturation polarization strengthens with increasing Ti content due to the change of ion-radius. On the other hand, the switching field decreases, which means the enhancement of ferroelectricity. The phase structure and polarization of the films can be tuned by a small amount of Ti doping, and then the energy storage characteristics of the thin films can be modulated. The results showed that a large energy storage density (W_rec) of 49.7 J/cm³ and efficiency (η) of 54% were achieved in the x = 1.5%. Moreover, the x = 1.5% sample displayed excellent cycling stability up to 1 × 10⁶ cyclings, which demonstrated that La and Ti co-doped films can be considered as potential candidates for future energy storage devices.