Effect of Rotational Speed on Microstructure and Optical Properties of Bismuth Ferrite Oxide (BiFeO₃)

Abstract

BiFeO3 films were deposited on quartz substrate using chemical solution deposition (CSD) and spin coating techniques with variations of rotational speed (1000 rpm, 2000 rpm, and 3000 rpm) and several films (4 layers and 8 layers). It characterized microstructure of films using X-Ray Diffraction (XRD), morphology, and cross-section using SEM and optical properties using UV-Vis. The results of characterization showed that an enhancement rotational speed causes the intensity of crystal field orientation to decrease, crystallite size, and crystallinity are the same. Surface morphology is getting smoother, flatter, lower porosity and the grain to be homogeneous with thinner thickness. Addition on the number of films causes higher intensity, crystallite size and crystallinity are the same. The film gets thicker, the morphology gets rough, and the boundaries between grains become clearer. Increasing the rotational speed and number of films causes the refractive index and extinction coefficient to be smaller. The light disperses measurement shows a linear relationship between photon energy and refractive index. Energy band gap generated between 2.2-2.5 eV.

Influence of film thickness on microstructure and optical properties of Bismuth Ferrite (BFO) for photovoltaic application

“…This induces the larger grain on the film with 8 layers thickness. These results are in accordance with previous study in [23]. its value significantly decreases in the UV light region (400 nm -200 nm).…”