High energy storage density at low electric field of ABO₃ antiferroelectric films with ionic pair doping

PbZrO₃ antiferroelectric films can be used to design the energy storage capacitors for low electric field applications, and the energy storage properties are determined by electric field-induced phase transition. Here we present a simple and effective method to enhance the energy storage properties of PbZrO₃ antiferroelectric through ionic pair (with small ionic radius) doping. Li⁺-La³⁺ pair induces chemical press when Li⁺ and La³⁺ are doped at the Pb²⁺-sites of PbZrO₃. Both the analysis based on the phenomenological model and experiment results show that the critical electric fields corresponding to the field-induced phase transition of PbZrO₃ can be enhanced under the compressive stress, which improves the energy storage properties. A maximum energy storage density of 16.2 J/cm³ has been obtained in Pb_0.96(Li_0.5La_0.5)_0.04ZrO₃ thin films at a low electric field of 600 kV/cm, which is about 1.8 times than that of un-doped PbZrO₃ films (9 J/cm³). The results provide an effective approach to design high energy storage properties in ABO₃ antiferroelectrics at low electric field.