Photonic crystals fabricated using patterned nanorod arrays

A bottom-up process for fabricating 2D photonic crystal (PC) slabs starting with patterned ZnO nanorod arrays that were conformally coated with TiO ₂ by template-assisted atomic layer deposition (ALD) was discussed. The space between the ZnO nanorods was partially filled with TiO₂, thus forming a continuous ZnO/TiO₂ matrix with a highly ordered air-hole array. The periodic structure showed a reflection peak close to the theoretically predicted bandgap region. It was shown that the technique is a self-assembly process that is entirely bottom-up and can be effectively and economically scaled up for large-sized 2D PC fabrication.