title: Anomalous Fluorescence Enhancement from Double Heterostructure 3D Colloidal Photonic Crystals--A Multifunctional Fluorescence-Based Sensor Platform.
abstract: Augmenting fluorescence intensity is of vital importance to the development of chemical and biochemical sensing, imaging and miniature light sources. Here we report an unprecedented fluorescence enhancement with a novel architecture of multilayer three-dimensional colloidal photonic crystals self-assembled from polystyrene spheres. The new technique uses a double heterostructure, which comprises a top and a bottom layer with a periodicity overlapping the excitation wavelength (E) of the emitters, and a middle layer with a periodicity matching the fluorescence wavelength (F) and a thickness that supports constructive interference for the excitation wavelength. This E-F-E double heterostructure displays direction-dependent light trapping for both excitation and fluorescence, coupling the modes of photonic crystal with multiple-beam interference. The E-F-E double heterostructure renders an additional 5-fold enhancement to the extraordinary FL amplification of Rhodamine B in monolithic E CPhCs, and 4.3-fold acceleration of emission dynamics. Such a self-assembled double heterostructure CPhCs may find significant applications in illumination, laser, chemical/biochemical sensing, and solar energy harvesting. We further demonstrate the multi-functionality of the E-F-E double heterostructure CPhCs in Hg (II) sensing.
authors.affiliation: Queensland Micro- and Nanotechnology Centre &School of Engineering, Griffith University, Nathan, QLD 4111, Australia.
authors.forename: Ehsan
authors.initials: E
authors.lastname: Eftekhari
authors.affiliation: Queensland Micro- and Nanotechnology Centre &School of Engineering, Griffith University, Nathan, QLD 4111, Australia.
authors.forename: Xiang
authors.initials: X
authors.lastname: Li
authors.affiliation: Queensland Micro- and Nanotechnology Centre &School of Engineering, Griffith University, Nathan, QLD 4111, Australia.
authors.forename: Tak H
authors.initials: TH
authors.lastname: Kim
authors.affiliation: Centre for Micro-Photonics and CUDOS, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, VIC 3122, Australia.
authors.forename: Zongsong
authors.initials: Z
authors.lastname: Gan
authors.affiliation: CSIRO Materials Science and Engineering, Clayton, VIC 3168, Australia.
authors.forename: Ivan S
authors.initials: IS
authors.lastname: Cole
authors.affiliation: Department of Chemistry &Laboratory of Advanced Materials, Fudan University, Shanghai, 200433, P.R. China.
authors.forename: Dongyuan
authors.initials: D
authors.lastname: Zhao
authors.affiliation: Centre for Quantum Dynamics, Griffith University, Nathan, QLD 4111, Australia.
authors.forename: Dave
authors.initials: D
authors.lastname: Kielpinski
authors.affiliation: Centre for Micro-Photonics and CUDOS, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, VIC 3122, Australia.
authors.forename: Min
authors.initials: M
authors.lastname: Gu
authors.affiliation: Queensland Micro- and Nanotechnology Centre &School of Engineering, Griffith University, Nathan, QLD 4111, Australia.
authors.forename: Qin
authors.initials: Q
authors.lastname: Li