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

Abstract

Nanosphere lithography and antireflection coating techniques have been applied to fabricate wide-angle antireflection structures on multicrystalline silicon substrates. Self-assembled 550-nm SiO2 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%.