Semitransparent Periodic Nanostructures Grown under Polarized Incoherent Light for Diffractive Applications

Periodic nanostructures, including gratings, which have been widely used in the fields of photonics and plasmonics, are generally fabricated through electron beam lithography, photolithography, or laser-induced periodic surface structure (LIPSS) formation. Although photomasks or photoresists are not necessary for the preparation of LIPSSs, a laser is required as a coherent light source. Here, we propose a photoelectrochemical bottom-up approach to obtain semitransparent periodic nanostructures using an incoherent continuous light source. Lead oxide nanoband arrays are formed simply by irradiating linearly polarized light to a potential-controlled indium-tin oxide electrode in the presence of Pb2+ ions. The polarized light causes anisotropic growth of lead oxide parallel to the polarization direction, and interference between incident light and light scattered from the nanostructures gives rise to the periodicity. The pitch of the subwavelength scale can be controlled by the irradiation light wavelength.