Optoelectronic Functionality of BiFeO3–SrTiO3 Interface.

One effective way to extend the functional degree of freedom for semiconductors is to introduce structural defects (e.g., surface or interface) and chemical defects as they commonly exist and modify the properties of the entity. Here, the optoelectronic properties of bismuth ferrite thin films and their tuning by the interface between the film and the strontium titanate substrate are reported. The defects that have been demonstrated, especially oxygen vacancies, are of paramount importance in the photoelectric properties of a film‐substrate system. A detailed analysis of the oxygen vacancy levels supports the role of the interface in carrier transport. These results provide a new strategy to design the optoelectronic device via usual defect doping and interface coupling. [ABSTRACT FROM AUTHOR]