Controllable synthesis of periodic flower-like ZnO nanostructures on Si subwavelengthgrating structures

Abstract

We report on the periodic well-defined flower-like zinc oxide (ZnO) nanostructures(NSs) self-assembled through a simple hydrothermal method using silicon (Si)subwavelength grating (SWG) structures. The Si SWGs serve as building blocksfor constructing a two-dimensional (2D) periodic architecture to integrate theone-dimensional (1D) ZnO NSs. Various controlled morphologies of ZnO NSs with highcrystallinity are obtained by changing the growth conditions. For 1D ZnO NSsintegrated on periodic hexagonal Si SWG structures, the reflection characteristics areinvestigated in comparison with the conventional ZnO nanorod (NR) arrays. For athree-dimensional (3D) flower-like ZnO NS on Si SWGs, a relatively low total reflectance of < 8% at wavelengths of 300–1050 nm is achieved compared to the ZnO NRs on Si substrate.