Impact of Absorption on the Bulk Photovoltaic Effect of Polycrystalline Bismuth Ferrite Thin Films

In this work, we investigated the bulk photovoltaic effect of bismuth ferrite (BFO) thin films. The BFO photovoltaic cell was constructed using a vertical structure between the transparent indium tin oxide (ITO) and a Cu/Ni alloy electrode. The cells were synthesized using sol-gel method and checked using XRD for the correct material phase. By spin-coating the materials onto the ITO substrate with various layers, we fabricated the thin film cells with different thickness, thus different absorption for the incident light. By illuminating the cell with standard solar spectrum (AM 1.5 G), we measured the induced photocurrents, I-V curves of the cells and the resistance of the films.