Antireflection and Scattering Properties of Two-Dimensional Hexagonal AZO Gratings on Glass Substrates

With photoresist dot arrays fabricated by a two-beam interference lithography as an etch mask, two-dimensional (2-D) hexagonal aluminum-doped zinc oxide（AZO）submicron gratings (SMG) with 160nm height (h) and different periods (P) were produced using lift-off transfer process. Results show that as P decreased to 487nm, SMG exhibited excellent antireflection properties, which reduced the average total reflectivity (Rtotal) from 11.8% of AZO thin film to 4.7% in the wavelength range of 400nm-1050nm, and promoted the total transmittance (Ttotal) significantly, especially in the long spectral range of 750nm-1050nm. On the other hand, as P increased from 487nm to 985nm, the haze parameters of reflectance (HR) or transmittance (HT) improved from 25.5% to 40.2% or from 15.1% to 36.8%, respectively. Nevertheless, P increased from 985nm to 1435nm, both Rtotal (or Ttotal) and HR (or HT) varied very slightly. Bidirectional distribution functions at normal incidence not only verified that the larger the P was, the part of diffuse reflectance (or transmittance) were much higher, but also further demonstrate the larger the P, the smaller the diffaction angle. In summary, 2-D hexagonal AZO SMG show promising antireflection effects at P less than 487nm, and show promising scattering abilities at P about 985nm.