Controlling transport properties at LaFeO₃/SrTiO₃interfaces by defect engineering

The formation of conductive LaFeO₃/SrTiO₃interfaces is first time reported by pulsed laser deposition via controlling the defects of SrTiO₃, which are closely related to the surface of substrate. It is found that the interfaces grown on SrTiO₃substrates without terraces exhibit the two dimensional electron gas. Moreover, the conductive interfaces show a resistance upturn at low temperatures which is strongly diminished by light irradiation. These interfaces favor the persistent photoconductivity, and the enormous value of relative change in resistance, about 60 185.8%, is also obtained at 20 K. The experimental results provide fundamental insights into controlling the defects at conductive interfaces of oxides and paving a way for complex-oxides based optoelectronic devices.