Abstract
We demonstrate a practical optoelectronic application of ZnO nanorod arrays (NRAs) synthesized by a hydrothermal method serving as an antireflection coating (ARC). ZnO NRAs exhibit broadband and omnidirectional AR characteristics for unpolarized, transverse electric polarized, and transverse magnetic polarized light, which arise from the length variation of NRA profiles. Due to growth on any surface of devices/substrates with ease, ZnO NRAs as the broadband and omnidirectional ARCs can benefit greatly the performance of optoelectronic devices, such as light-emitting diodes and photovoltaics.