Microstructure And Electrical Properties Of PbZrO₃-Al₂O₃ Nanocomposite Thin Films Annealed By Microwave

For a long time,energy storage technology has received close attention in the academic and industrial fields.Compared to other dielectric materials,dielectric capacitors using antiferroelectric materials can exhibit higher energy storage density and faster charge discharge rates.As a typical antiferroelectric material,Pb Zr O₃（PZO）has greater potential in practical energy storage applications due to its unique field induced phase transition behavior and high Curie temperature.The energy storage performance of dielectric materials mainly depends on their polarization performance and electric field breakdown strength,and nanocomposition is one of the effective methods to improve the polarization performance and electric field breakdown strength.Here,a novel method to prepare PbZrO₃-Al₂O₃nanocomposite films by chemical solution deposition combined with thermal evaporation of metal Al layer is proposed,the polarization and energy storage properties of PZO thin films are regulated by microwave annealing.The main research results are as follows:A metal Al layer was prepared on a Pt/Ti/SiO₂/Si substrate by adjusting the evaporation voltage and current to control the evaporation rate.The Al layer was characterized by AFM,XRD,SEM,and EDS.The results showed that when the evaporation rate was 0.1（?）/s,the Al layer had a minimum root mean square roughness of 0.528 nm,and the Al layer was amorphous phase with uniform distribution on the substrate.The sol-gel method was used to spin coat PZO on the substrate covered by Al layer,and the conventional annealing method was used for crystallization treatment.The results show that the Pb Zr O₃-Al₂O₃composite films with Al₂O₃nanoparticles（NPs）distributed on the Pb Zr O₃matrix in a layered manner can be prepared by this method,and the shape and characteristics of the polarization-electric field（P-E）hysteresis loop of the composite films can be controlled by changing the thickness of the metal Al layer.When the volume fraction of the Al layer is 0.6%,the Pb Zr O₃-Al₂O₃nanocomposite film achieves a recoverable energy density of 15.83 J/cm³under an electric field of 970 k V/cm,which is 105%higher than the pure PZO film.In addition,the effects of Al₂O₃nanoparticles on the microstructure,polarization properties,leakage current,and energy storage properties of composite films were systematically studied.With the increase of the content of Al₂O₃nanoparticles,the polarization properties of the composite film gradually evolve from antiferroelectric characteristics to ferroelectric characteristics,with the maximum polarization,remanent polarization,and electric field breakdown strength increasing,and the leakage current decreasing.The PbZrO₃-Al₂O₃nanocomposite films were prepared by microwave annealing after spin coating PZO on Al coated substrates by sol-gel method.The effects of microwave annealing on the microstructure,electrical properties,and energy storage properties of the composite films were studied.The results show that Pb Zr O₃-Al₂O₃nanocomposite films with small grain size and dense microstructure can be obtained by microwave annealing at650°C in only 10 minutes.Under an electric field of 1550 k V/cm,the recoverable energy storage density of the composite film is 18.94 J/cm³,and the energy storage efficiency is42%,showing relatively excellent energy storage performance.