Abstract：High-storage energy density is one of the critical issues in the development of low carbon and green energy technology nowadays. In order to explore the alumina thin film potential application as a dielectric in the high-storage energy density capacitors,DC Magnetron Sputtering technology has been applied to prepare dense Al2O3 films. X-ray diffraction( XRD) spectra show that the thin films are γ-Al2O3 in structure. Field-emission scanning electron microscope( FESEM) images of the films reveal a crack-free surface and a dense cross-section. Electrical and dielectric measurements are carried out on the samples with a metal-insulator-metal( MIM)structure. The Al2O3 thin films exhibit good dielectric properties. The calculated energy density of the Al2O3 film capacitors is about 7. 6 J / cm3.

Keyword：DC Magnetron Sputtering;alumina films;dielectric constant;high energy density;