Urchin-aggregation inspired closely-packed hierarchical ZnO nanostructures for efficient light scattering

We reported the enhancement of light scattering in the urchin-aggregation shaped closely-packed hierarchical ZnO nanostructures, fabricated by a simple and scalable process based on the hydrothermal method utilizing the silica microspheres monolayer as a two-dimensional periodic template. From theoretical predictions, the diffuse light scattering is closely related to the size of silica microspheres as light diffusion centers. Moreover, the ZnO nanorod arrays on silica microspheres monolayer provide the further enhancement of light scattering. The experimentally fabricated urchin-aggregation shaped ZnO nanostructures using silica microspheres of 970 nm indicated a high density of ZnO nanorods with a wide bending angle, which led to the largely increased photoluminescence intensity and a high transmittance haze ratio of > 70% in the wavelength range of 400-900 nm in keeping with a high total transmittance. The contact angles of a water droplet on the surface of the samples were also explored. (C) 2011 Optical Society of America