Semiconductor properties of anodic oxide film formed on aluminum

The semiconductor properties of anodic oxide film formed on commercial pure aluminum were analyzed using Mott-Schottky theory and point defect model (PDM). The donor density, oxygen vacancy diffusion coefficient and flat-band potential were measured for the oxide films sealed by boiling water and K2Cr2O7, respectively. The results indicated that the anodic oxide films showed the n-type semiconductor property and the donor density decreased exponentially with the voltage elevating. The value of oxygen vacancy diffusion coefficient is about (1.12-5.53)x10(-14) cm(-2) . s(-1). The flat-band potential of anodic oxide film declined after sealing.