be roughly divided into perovskite-type, lithium niobate type, tungsten bronze type, potassium dihydrogen phosphate type, triglycine sulphate type, Rochelle salt, ferroelectric liquid crystal, and ferroelectric polymer. Among these ferroelectric thin film materials, perovskite ferroelectric films and ferroelectric polymer films are relatively well-studied films. The outstanding ductility and flexibility of ferroelectric polymer films like polyvinylidene fluoride (PVDF) have made them popular in flexible electrical devices. [7][8][9] However, some disadvantages of ferroelectric polymer films, such as low polarization strength, large coercive field, slow switching speed, and poor temperature resistance limit their application in fields including ferroelectric memory, piezoelectric energy harvesting or sensors. [10][11][12] To apply them to these fields, they need to be appropriately combined with perovskite oxide materials to improve their ferroelectric properties. For example, some researchers doped 0.5((Ba 0.7 Ca 0.3 )TiO 3 )-0.5(Ba(Zr 0.2 Ti 0.8 ) O 3 ) (BCZT) ceramic particles into PVDF to make BCZT/PVDF composite film. PVDF is a semicrystalline ferroelectric polymer, doping it with BCZT improves its crystallinity and hence its dielectric constant. The dielectric constants of the γ-PVDF phase and α-PVDF phase in pure PVDF films are ≈10 and 7.5. After doping with BCZT, the dielectric constants increase to 31 and 20, which improves the ferroelectric properties of PVDF. [13] There are many other examples of enhancing the ferroelectric properties of PVDF films by doping with perovskite oxides. [14][15][16][17][18][19][20] Obviously, enhancing the ferroelectric properties of PVDF by this method will make the preparation process relatively tedious and is not conducive to mass production. It is not as convenient as growing perovskite ferroelectric films directly on flexible substrates. In addition, polymers' poor temperature resistance limits their utilization compared to ferroelectric oxide thin film materials' superior temperature resistance and physical properties. The composite dielectric film composed of BiFeO 3 (BFO) and SrTiO 3 (STO) has a reversible energy storage density (U e ) of about 70 J cm −3 at room temperature and can operate stably between −60 and 100 °C. [21] BaZr 0.35 Ti 0.65 O 3 (BZT) has a U e of 78.7 J cm −3 at room temperature and can work stably between −150 and 200 °C, and the U e still exceeds 40 J cm −3 at 200 °C. [22] But polymer-based ferroelectric materials often cannot be applied at high temperatures and have a low energy storage density (<40 J cm −3 ). [23,24] The high temperature special design can meet the temperature requirements, but the dielectric properties need more optimization. [25,26] The spontaneous polarization of BaTiO 3 (BTO) is about 25 µC cm −2 , [27] and the spontaneous polarization of stress-modulated BTO Perovskite oxide thin film materials are used in various fields of human life due to their excellent physical properties. The high performance thin films in turn prov...