Effect of cooling oxygen pressure on the photoconductivity in Bi0.9La0.1FeO3 thin films

•We observe distinct relations between photoconductivity and cooling oxygen pressure.•Lower oxygen vacancies (VOs) show obviously decrease in leakage current.•Higher level of VOs led to the higher free carrier concentration and hence.•Higher level of VOs is responsible for the increase in higher photoconductivity.•The conductive mechanism is dominated by space-charge-limited conduction.

A direct correlation is observed between the magnitude of the photoconductivity and cooling oxygen pressure in Bi0.9La0.1FeO3 films. With lower oxygen vacancies (VOs) films cooled in higher oxygen pressure show obviously decrease in leakage current. Higher level of VOs led to higher free carrier concentration and hence is believed to be responsible for the increase in higher photoconductivity. It is evident that BLFO films with higher VOs cooled in lower oxygen pressure and/or light illumination induce a higher carrier injection, ni and thus the conductive mechanism is dominated by space-charge-limited conduction.