title: Mesostructured dye-doped titanium dioxide for micro-optoelectronic applications.
abstract: Optically transparent, mesostructured titanium dioxide thin films were fabricated using an amphiphilic poly(alkylene oxide) block copolymer template in combination with retarded hydrolysis of a titanium isopropoxide precursor. Prior to calcination, the films displayed a stable hexagonal mesophase and high refractive indices (1.5 to 1.6) relative to mesostructured silica (1.43). After calcination, the hexagonal mesophase was retained with surface areas > 300 m2 g-1. The dye Rhodamine 6G (commonly used as a laser dye) was incorporated into the copolymer micelle during the templating process. In this way, novel dye-doped mesostructured titanium dioxide films were synthesised. The copolymer not only directs the film structure, but also provides a solubilizing environment suitable for sustaining a high monomer-to-aggregate ratio at elevated dye concentrations. The dye-doped films displayed optical thresholdlike behaviour characteristic of amplified spontaneous emission. Soft lithography was successfully applied to micropattern the dye-doped films. These results pave the way for the fabrication and demonstration of novel microlaser structures and other active optical structures. This new, high-refractive index, mesostructured, dye-doped material could also find applications in areas such as optical coatings, displays and integrated photonic devices.
authors.affiliation: Department of Chemistry & Centre for Nanotechnology and Biomaterials, University of Queensland, Brisbane, QLD 4072, Australia.
authors.forename: Robert
authors.initials: R
authors.lastname: Vogel
authors.forename: Paul
authors.initials: P
authors.lastname: Meredith
authors.forename: Indriana
authors.initials: I
authors.lastname: Kartini
authors.forename: Michael
authors.initials: M
authors.lastname: Harvey
authors.forename: Jamie D
authors.initials: JD
authors.lastname: Riches
authors.forename: Alexis
authors.initials: A
authors.lastname: Bishop
authors.forename: Norman
authors.initials: N
authors.lastname: Heckenberg
authors.forename: Matt
authors.initials: M
authors.lastname: Trau
authors.forename: Halina
authors.initials: H
authors.lastname: Rubinsztein-Dunlop