Wide-angle antireflection ZnO films on bullet-like nanostructures of multi-crystalline silicon

Nanosphere lithography and antireflection coating techniques have been applied to fabricate wide-angle antireflection structures on multicrystalline silicon substrates. Self-assembled 550-nm SiO ₂ nanospheres were arranged periodically to act as a mask to block the inductively coupled plasma dry etching and form bulletlike nanostructures on the surface of the multicrystalline silicon wafer. Then a 65-nm-thick zinc oxide film was deposited on the nanostructures using the atomic layer deposition method. The results show that when applying the nanostructure with a ZnO film the average reflectivity of the multicrystalline silicon wafer can be decreased from 36 to 0.65 in the wavelength range from 400 nm to 850 nm for an incident angle of 8. When the incident angle reaches 60 the average reflectivity of the sample becomes less than 4.6.