First-principles investigation of bandgap tailoring in tetragonal Bi2FeCrO6 by magnetic ordering and B-site-cation ordering

The development of ferroelectric photovoltaic (FE-PV) materials has been limited for a long time due to their large bandgap. Many strategies for lowering the bandgap have been suggested to promote FE-PV properties. The effects of magnetic ordering and B-site-cation ordering to lower the bandgap of FE-PV are investigated in this paper using first-principles calculations. Results show that the most stable structure of tetragonal Bi2FeCrO6 (t-Bi2FeCrO6 ) is the AS1 structure (Fe/Cr alternate stacking ordering) with C-type antiferromagnetic ordering (defined as AC-t-Bi2FeCrO6), which has a small bandgap, suggesting that AC-t-Bi2FeCrO6 is among the FE-PV materials with the highest application potential.