Abstract |
Sol-gel derived photonic bandgap films have been investigated as possible multilayer coatings for solar control glass applications. Multilayer Bragg mirrors, in particular, have been modelled by the Transfer Matrix method, designed to have either near-UV or near-IR reflectivity, but visible transparency, based on alternating aluminosilicate glass/titania quarter-wave stacks. Such composite multilayer structures have been deposited by sol-gel processing on selected glasses and other types of substrates and their optical characteristics have been measured by optical absorption and reflection spectroscopies, as well as spectroscopic ellipsometry to determine the single layer refractive index and thickness. The UV-visible-IR absorption and reflection characteristics of these multilayer coatings revealed solar control properties, due to the presence of peaks near similar to 350-400 nm and similar to 900-1000 nm, with reflectivities of the order of 70\%, which appear promising for solar control application. (C) 2011 Elsevier B.V. All rights reserved. |