Isotropic photonic pseudogap in electrodeposited ZnO inverse opal

The authors achieved an isotropic photonic stop band in the blue region near the L point in the Brillouin zone of ZnO inverse opal. This was fabricated by electrochemical infiltration in a polystyrene opal template self-assembled with the meniscus method. In the ZnO inverse opal, the stop band is "blueshifted," widened (compared to its parent opal), and remained fixed at its central frequency along different directions. The extensive spectral overlap of the stop bands indicates a smooth angular dispersion approaching omnidirectionality within a specific range of directions. The isotropic pseudogap could interact with the emission of ZnO material, resulting in useful luminescent behavior.