Dielectric property and self-repairing capability of silicon and titanium co-doped amorphous alumina thin films prepared by sol-gel technology

作者：Feng, Qian; Yao, Manwen^*; Su, Zhen; Yao, Xi

来源：Journal of Materials Science: Materials in Electronics , 2018, 29(19): 16581-16589.

DOI：10.1007/s10854-018-9751-3

• ENERGY DENSITY
• POLYMER NANOCOMPOSITES
• ELECTRICAL-PROPERTIES
• AL2O3 FILMS
• GLASSES
• STORAGE

In this article, (Al1-0.02-xSi0.02Tix)(2)O-y (x = 0.2, 0.9 and 2%) thin films were prepared on Pt/Ti/SiO2/Si substrates using sol-gel technique. The dielectric properties of undoped and Si-Ti co-doped Al2O3 thin films were investigated. The leakage current of (Al0.971Si0.02Ti0.009)(2)O-y thin film is reduced by 2 orders of magnitude compared with Al2O3 film. Meanwhile, the modified sample exhibits the ultrahigh energy density of 14.01 J/cm(3) under the breakdown strength of 647 MV/m, which is an enhancement of 11.26 J/cm(3) over that of the undoped Al2O3 film. The improvement of dielectric properties is ascribed to the forming of Al-O-Si, Al-O-Ti bonds and the anodic oxidation of Ti3+, which could strengthen the stability of Al2O3 structure and self-repair the defects of the films under applied electric field. Another reason is that cation vacancies generated by Si-Ti co-doping could effectively prevent the formation of oxygen vacancies and decrease the breakdown probability of the films. This work provides a promising route to dielectric thin films materials for electrical energy storage applications.

• 出版日期2018-10
• 单位同济大学