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

Abstract

Bismuth Ferrite (BFO) film with a low bandgap value is a promising candidate for photovoltaic applications. This study discussed the effects of film thickness on the microstructure and optical properties of BFO films. BFO films were deposited on the Quartz-Silicon substrates using the chemical solution deposition (CSD) method. The thickness variation was conducted by varying the deposited layer number which correspond to the thickness values of 252 and 405 nm, respectively. The XRD analysis showed that increasing of films thickness had no significant effect on the crystal structure. It revealed that the XRD peak intensities increase, however, the lattice parameters, crystallite size, and crystallinity are relatively in the close values as the increasing films thickness. The Scanning Electron Microscopy (SEM) analysis exhibited the larger grain size of the BFO films with the increasing films thickness. According to the UV-Vis spectrophotometer results, the bandgap values reduced from 2.48 eV to 2.5 eV as the thicker film. Finally, The I-V curve presented that the higher films thickness induced the higher efficiency of the BFO film from 0.97 % to 2.1%. The BFO film with higher thickness could exhibit the better performance for photovoltaic application.