Three-Dimensionally Ordered Macroporous ZrO₂:Eu³⁺: Photonic Band Effect and Local Environments

Abstract

Three-dimensionally ordered macroporous (3DOM) ZrO 2:Eu 3+ inverse opal materials prepared by polystyrene (PS) colloidal crystal templating, using the sol−gel method, were successfully fabricated. Their crystal structure, morphology, and photoluminescence (PL) properties and the effect of the photonic stop-band on the spontaneous emission of Eu 3+ ions were studied and compared with those of the nonporous sample. In the 3DOM ZrO 2:Eu 3+, significant suppression for the 5 D 0 - 7 F 1 transition peaking at 590 nm was observed, which was in good agreement with the photonic band gap calculated (∼586 nm). After grinding the 3D ZrO 2:Eu 3+ inverse opal material, the suppression of emission was restored due to the disappearance of the photonic band gap. In the 3DOM ZrO 2:Eu 3+, the luminescent lifetime of 5 D 0 - 7 F J depended strongly on emission wavelengths, which was mainly attributed to the appearance of different Eu 3+ centers. In the 3DOM ZrO 2:Eu 3+, three symmetry sites for Eu 3+ were identified by site-selective excitation, differing from the nonporous sample, in which only one site was identified.