Chemical Solution Deposition of Single-Phase BiFeO3 Thin Films on Transparent Substrates

Abstract

The production of high-quality BiFeO3 thin films on cost-effective transparent electrodes for visible light harvesting applications and devices remains a challenge. Here, the production of single-phase nanostructured BiFeO3 thin films via chemical solution deposition (CSD) on transparent conductive fluorine-doped tin oxide FTO glass substrates is reported. It is shown that BiFeO3 is of high purity using a variety of analytical tools and that the as-obtained BiFeO3 thin films have a single-grain single-domain structure exhibiting ferroelectric switching under poling. The BiFeO3 samples show visible light absorption with a bandgap of 2.7 eV under all processing conditions. By changing the annealing atmosphere, it was possible to modify the photocurrent produced, which were (at 1.23 VNHE) 0.07 (O2-annealed), 0.02 (air-annealed), and 0.01 mA cm−2 (Ar-annealed). This indicates a change in the mobile carriers available. The results show that it is possible to produce single-phase BiFeO3 on a transparent conductive electrode system with controllable photoconductivity.