Optical filtering properties of TiO2/Al2O3 heterostructures from first principles

Abstract

This study combines the use of the full potential linear-augmented plane wave method (FP-LAPW) within the framework of the density functional theory (DFT) and the optical matrix approach for modeling the multilayer assembly. A new class of heterostructures with sufficient number of alternating layers of rutile- TiO 2 (as a high index material) and α- Al 2 O 3 (as a low index material) are proposed and their transmittance spectra are investigated. This study shows that the number of alternating layers, and the thickness and arrangement of them should be considered in making a heterostructured filter. The relation between heterostructure parameters and narrow-band-pass peaks of transmittance spectra is investigated. The proposed model seems to be successful in predicting the optical behavior of heterostructures and simulations agree well with the experimental observations. In addition, our model is very flexible and the effect of other parameters such as incident angle and light polarization can be easily investigated.