Optical absorption modulation in ZnO hemisphere nanorod arrays fabricated by nanoimprint lithography

Nanostructured light trapping has emerged as a promising route toward the high performance solar cells and other optical devices. In this work, ZnO hemisphere nanorod arrays were fabricated by nanoimprint lithography technique combined with low temperature hydrothermal growth process. By using the nanoimprint techniques, patterned ZnO nanodome arrays with light trapping effect in the visible region (450 nm and 640 nm) were obtained. And then through controlling the precursor concentration and the reaction time in the hydrothermal process, the density and periodicity of ZnO hemisphere nanorod arrays could be adjusted easily. Meanwhile, the light trapping effect in the visible region can be modulated from 450,640 nm to 480,650 nm which was proved to be correlative with the periodicity of the ZnO hemisphere nanorod arrays. Thus fabricate ZnO hemisphere nanorod arrays with controllable periodicity and understanding light trapping effect in it is not only of fundamental interest, but also of technological importance. © 2016 Inderscience Enterprises Ltd.