The 12th Global Conference on Materials Science and Engineering (CMSE 2023)

Abstract: In this work, we have presented data on upconversion luminescence from a sol-gel derived BaTiO₃ target and film structures doped with Er and Yb (BaTiO₃:(Er,Yb)). We synthesized several different types of materials and film structures which demonstrated Er³⁺ upconversion luminescence: (a) the target form, which used the explosive compaction method for sol-gel-derived BaTiO₃:(Er,Yb) powder; (b) the single-layer spin-on BaTiO₃:(Er,Yb) xerogel films deposited on fused silica, silicon and silicon coated with sol-gel derived porous SrTiO₃ layer; (c) the microcavities with an undoped SiO2/BaTiO3 Bragg reflector surrounding a BaTiO₃:(Er,Yb) active layer, (d) the films deposited from suspension of undoped BaTiO₃ sol and BaTiO₃:(Er,Yb) particles doped with erbium and ytterbium. The BaTiO3:(Er,Yb)/SiO₂ microcavity exhibited an enhancement of the upconversion luminescence when compared to the BaTiO₃:(Er,Yb) double-layer film fabricated directly on a crystalline silicon substrate. The optical band gap for the indirect optical transition in the single layer of the BaTiO₃:(Er,Yb) spin-on film annealed at 450 °C was estimated to be 3.82 eV, while that for the film annealed at 800 °C was approximately 3.87 eV. The reflection spectra of the BaTiO₃:(Er,Yb)/SiO₂ microcavity demonstrated a deviation of the maxima of the reflection within 15% and a shift of the cavity mode by 10 nm for temperature measurements ranging from 20 to 130 °C, and these effects depend on the annealing temperature of the microcavity. The potential applications of the BaTiO₃:(Er,Yb) sol-gel-derived structures for remote optical monitoring are discussed.

Keywords: Sol-gel, erbium, ytterbium, upconversion, luminescence

Biography: Prof. Nikolai Gaponenko graduated from Belarusian State University, Faculty of Physics, in 1985. From 1985 to date, he has worked at the Belarusian State University of Informatics and Radioelectronics, where he received his PhD in 1992 and his Habilitation in 2005. He developed the conception of sol-gel synthesis in mesoporous materials, including colloidal photonic crystals and porous anodic alumina films, illustrating the shift of the photonic stop band and enhanced luminescence of lanthanides under UV and X-ray excitation for the structures of the xerogel/porous matrix. He is the head of the laboratory of nanophotonics and a full professor. Seven PhDs were supervised by him. He is the co-author of 100 scientific papers indexed by Scopus, one solo book, and three reviews. His current research focuses on enhanced upconversion luminescence from low-cost sol-gel-derived film structures.