Xueguang Huang

Energy transfer enhancement in Eu3+ doped TbPO4 inverse opal photonic crystals

Photoluminescence of Eu3+ doped TbPO4 (TbPO4:Eu) inverse opal photonic crystals was investigated. The results showed that the energy transfer from the donor Tb3+ to the acceptor Eu3+ can be enhanced effectively by the photonic band gaps in the photonic crystals. When the fluorescence emission wavelength of the donor Tb3+ overlapped the photonic band gap, the fluorescence intensity of the acceptor Eu3+ was obviously enhanced due to the inhibition of radiative emission of donor in the inverse opal photonic crystals.

Energy transfer between fluorescent dyes in photonic crystals

Energy transfer from fluorescein (Fl) to Rhodamine B (RhB) in the opal photonic crystals has been investigated by photoluminescence. The results show that the energy transfer can be enhanced effectively by photonic bandgaps. When the fluorescence emission wavelength of donor Fl overlaps the photonic bandgap the fluorescence intensity of the donor is suppressed, while the fluorescence intensity of acceptor RhB is obviously enhanced. This enhancement can be attributed to the inhibition of radiative emission of the donor in the photonic crystals.

Template-induced directional growth of ZnO nanomeshes by colloidal crystals

The formation of materials with controllable morphologies is of great significance both in science and technology. In this paper, a new method for controlling the morphology of materials is introduced: the chemical effects and the geometric restriction of the template are both utilized for determining the shape of growing materials. We report a thermodynamic study on the formation process of novel two-dimensional zinc oxide (ZnO) nanosheets with periodically porous structures (nanomeshes) grown in a template of colloidal crystals by an electrochemical-deposition method. The geometry restriction of the colloidal crystal template and the template-induced anisotropic environments are both introduced in the electrodeposition. ZnO nanomeshes along the {111}, {110}, and {100} crystalline planes of the colloidal crystals and nanomeshes with curved shapes are synthesized through the modification of the depositing conditions and template parameters. A model on the basis of thermodynamic stability is proposed to describe the relationship between the directional growth of nanomeshes and their influencing factors including surface energy, deposition time, and microsphere diameters.