Abstract
The preparation of responsive multilayered structures with quarter-wave design based on layer-by-layer deposition of sol-gel derived Nb2O5 films and spin-coated MEL type zeolite is demonstrated. The refractive indices (n) and thicknesses (d) of the layers are determined using non-linear curve fitting of the measured reflectance spectra. Besides, the surface and cross-sectional features of the multilayered structures are characterized by scanning electron microscopy (SEM). The quasi-omnidirectional photonic band for the multilayered structures is predicted theoretically, and confirmed experimentally by reflectance measurements at oblique incidence with polarized light. The sensing properties of the multilayered structures toward acetone are studied by measuring transmittance spectra prior and after vapor exposure. Furthermore, the potential of the one-dimensional photonic crystals based on the multilayered structure consisting of Nb2O5 and MEL type zeolite as a chemical sensor with optical read-out is discussed.
Highlights
Photonic crystals (PhCs) are artificial structures where media with two different refractive indices are arranged in a periodic manner with the period comparable to the wavelength of light in the visible and near infrared spectral ranges (500–1500 nm) [1,2]
In this study we demonstrate the preparation of one-dimensional photonic crystals based on MEL
When the Nb2O5 film is deposited on top of the MEL zeolite film, some interpenetration between the films is observed (Figure 2c), which is the reason of lack of clear boundary between them
Summary
Photonic crystals (PhCs) are artificial structures where media with two different refractive indices are arranged in a periodic manner with the period comparable to the wavelength of light in the visible and near infrared spectral ranges (500–1500 nm) [1,2]. Owing to the phenomenon of constructive interference certain stop bands open when the PhCs are probed with light incident at any direction. Under particular conditions the stop bands for different directions overlap and for the entire wavelength range light propagation is forbidden for all directions and polarization of incident light. The band of forbidden wavelengths is commonly referred to as “complete or 3D photonic band gap”. When the PhCs’ optical thicknesses (the product of refractive index and physical thickness) equal a quarter of the operating wavelength, the structures are called
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
