Tailoring the Optical and Sensing Properties of Sol–Gel Niobia Coatings via Doping with Silica and Noble Metal Nanoparticles
Year: 2025
Type: conference-paper
Abstract: Nb2O5 (niobia) coatings were prepared by spin coating of niobium sol, synthesized using niobium chloride as the precursor and ethanol and water as solvents, followed by high-temperature annealing. Doping of the films was achieved by incorporating commercially available SiO2 (Ludox) and noble metal nanoparticles (NPs) into the sol prior to its deposition. Various sizes of Pt (5 and 30 nm), Ag (10, 20, and 40 nm), and Au (5, 10, and 20 nm) NPs were used to enhance sensing behavior of coatings. After annealing, films were subjected to chemical etching to remove the silica phase. This process generated porosity within the films, which in turn enabled the tailoring of both their optical and sensing properties. It was demonstrated that both the type and size of the incorporated nanoparticles significantly influenced the sensing behavior. The most effective enhancement was observed with the addition of 10 nm AuNPs. Optical characterization indicated that 10 nm AuNPs had a minimal effect on the optical properties. In contrast, doping with 20 nm AuNPs led to a reduction in the refractive index and an increase in Urbach energy. No significant alteration in the optical band gap due to doping was observed.
Authors: Tsvetanka Babeva, Venelin Pavlov, Georgi Zlatinov, Biliana Georgieva, Penka Terziyska, Gergana Alexieva, Katerina Lazarova, Rosen Georgiev
Language: English
Subfield: Polymers and Plastics
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Award: G675437911
OpenAlex ID: W7087484178