Enhanced electrocaloric effect in a Si-doped PbZr0.95Ti0.05O3 film deposited on FTO substrate

Materials with an electrocaloric effect (ECE) have been extensively studied for their cooling applications. Most ECE films are oriented and are difficult to integrate into industrial production processes. Here, an ECE ( ΔS = 4.48 J K −1  kg −1 and ΔT  =   6.4 °C at ΔE  =   390 kV cm −1 ) is obtained in an unoriented PbZr 0.95 Ti 0.05 O 3 (PZT) film fabricated on an FTO substrate using an improved sol-gel method. To improve the ECE, Si-doped PZT films with 1–4 mol. % of Si are deposited. X-ray diffraction and X-ray photoelectron spectroscopy results confirm that Si was doped into the PZT lattice. The orthorhombic and tetragonal antiferroelectric phases coexist in the PZT/0.01 Si film. A large ECE ( ΔS  =   5.89 J K −1  kg −1 and ΔT  =   8.5 °C at ΔE  =   390 kV cm −1 ) is acquired in the PZT/0.01 Si film, which was measured by an indirect method. This work demonstrates that ECE of unoriented PZT antiferroelectric films on FTO substrates can be improved by a certain amount of Si doping.