Síntese de filmes finos cerâmicos de BaTiO3:Eu3+ depositados por spin coating com sinterização convencional e à laser

Abstract

This work presents a study on the fabrication of Eu 3+ doped BaTiO 3 thin films using the spin-coating method. Additionally, a comparison is made between the results obtained through the traditional resistive furnace sintering method and laser sintering of these films. The Pechini method was used to fabricate the precursor solution, which is based on the formation of a polymeric chain where precursor ions are anchored. Then, the solution was spin-coated onto 2 x 2 cm glass substrates and left to dry. After drying, the films underwent a traditional sintering procedure in a resistive furnace, and then some films were treated using a CO 2 laser. The microstructure and optical properties of the produced films were characterized using imaging and spectroscopic techniques, respectively. Optical microscopy, scanning electron microscopy, UV-Vis absorption spectroscopy, and photoluminescence measurements were used. The results show that conventionally produced films exhibit a homogeneous surface with few defects such as cracks or pores. Furthermore, the optical bandgap of these films was estimated to be 3.7 eV through UV-vis absorption measurements, which is in the range of the expected bandgap for BaTiO 3 . On the other hand, laser treatment induced the formation of new cracks, likely due to the temperature gradient during processing. Photoluminescence measurements showed a significant alteration in the width of the emission peaks when comparing the traditional samples with the laser-treated ones. This fact indicates that laser treatment not only induced microstructural modifications but also structural modifications in the matrix, as the luminescence of Eu 3+ is sensitive to the crystalline environment. Therefore, the results obtained in this study demonstrate that Eu 3+ doped BaTiO 3 thin films can be successfully produced using the traditional resistive furnace method with low-cost substrates, and laser sintering can also be successfully employed to modify the characteristics of these films, providing a more crystalline environment. These findings can contribute to the development of new materials and methodologies for applications related to optoelectronic device engineering.