Inverse opals coupled with nanowires as photoelectrochemical anode

Semiconductor nanowires-inverse opal hybrid architectures are designed and fabricated as a new type of photoelectrochemical photoanode. ZnO nanowire arrays are directly grown atop TiO ₂ inverse opals to form a bilayer structure with both electrical and optical coupling. In addition to the individual photocurrent contributions from the TiO ₂ and ZnO, the inverse opal plays an additional role in enhancing the light harvesting when the photonic stop bands are tailored at appropriate positions by tuning the opal size. Given the fact that materials for both the nanowires and inverse opal are widely available, our strategy offers a new approach to the fabrication of various nanowires-photonic crystal coupled structures for various solar energy applications.