Poling effect on structural and optical properties of Ba0.9Gd0.1TiO3 thin films for photovoltaic application

• Main Authors: Saif, Ala'eddin A., Yen Chin Teh
• Format: Conference Proceeding
• Language: English
• Subjects: Ba 0.9 Gd 0.1 TiO 3; Ferroelectric; Nonlinear optics; Optical band gap; Optical device fabrication; Optical films; Optical polarization; Photonic band gap; Poling; Substrates; UV-Vis
• ISSN: 2378-3451
• DOI: 10.1109/IREC.2017.7926003

A perovskite Ba 0.9 Gd 0.1 TiO 3 thin films have been successfully fabricated on SiO 2 /Si and silica substrates using Sol-gel technique. The effect of poling at different poling strength on structural and optical properties of the fabricated films has been investigated using AFM and UV-Vis spectrophotometer, respectively. The AFM results show that the grain size reduces from 195.72 nm for unpoled film to 88.67 nm for poled film at 2.5 kV. This reduction is attributed to crystal elongation and internal stress responding to poling mechanism. An increase trend is observed on average roughness, RMS roughness and maximum height of peak to valley roughness, as the poling voltage increases, which may be due to the interaction of electric field with the domain wall and dipole moments. The absorbance and transmittance spectra reveal that the absorption and transmission decrease as films poled. In addition, the optical band gap for unpoled, poled at 1.5 kV and poled at 2.5 kV films is found to be 2.9 eV, 2.846 eV and 2.727 eV, respectively. The decrease in absorbance, transmittance and band gap is attributed to the Ba 0.9 Gd 0.1 TiO 3 dipoles orientation within the films with respect to the applied electric field.