Persistent photoconductivity at LaVO3–SrTiO3 interface

Abstract Light illumination is widely used to tune the electronic properties of semiconductors. We have studied the effect of temperature and wavelength of light on the photoconductivity and persistent photocurrent (PPC) on an insulating (3 unit cells (u.c.) of LaVO3 (LVO) on SrTiO3 (STO)) and a conducting (5 u.c. of LVO on STO) oxide interface. Photo induced insulator to metal transition has been observed for the insulating interface. For 405 nm wavelength light illumination, the conducting interface shows PPC at all temperatures, however for 532 nm wavelength light, it shows PPC state only above 220K. For insulating sample, PPC has been observed only for 405 nm light illumination above ~150K. A model band structure has been presented to understand the experimental observations.