Highly Transparent and High Haze Bilayer Al-Doped ZnO Thin Film Employing Oxygen-Controlled Seed Layer

Abstract

Al-doped ZnO (AZO) film was continuously deposited by DC magnetron sputtering using pure Ar on a thin AZO seed layer prepared using an approximately 4% dilution of oxygen with Ar. X-ray diffraction measurements showed that the AZO film grown on the seed layer exhibited a much higher crystallinity and larger grain size than that without the seed layer. The electrical properties such as resistivity and Hall mobility were improved. The average visible transmittance was increased from 81.6 to 86.2%, and near infrared (NIR) transmittance was increased from 76.0 to 84.4% by employing the seed layer. The haze value characterizing the light scattering property was significantly increased from 59.4 to 89.5% in the visible region by the seed layer, and it was increased from 15.1 to 50.8% in the NIR region. Surface topography analysis showed that the bilayer AZO film had larger craters allowing for improvement of the light scattering properties than the conventional AZO film without the seed layer.