Conducting LaVO3/SrTiO3 Interface: Is Cationic Stoichiometry Mandatory?

The origin of the conductivity at the interface of two insulating perovskite oxides is a matter of intensive studies. The conductivity generated at the interface of insulating LaVO3 (LVO) and SrTiO3 (STO) is explained in terms of polar catastrophe. Here, the authors grown LVO films on (001) TiO2-terminated STO substrate employing pulsed laser deposition technique and demonstrate a transition from conducting to insulating interface by changing the La-stoichiometry by only 1%, whereby such transition takes place for La-deficient films. The effect of cation (non)stoichiometry of LVO film on both carrier density and mobility is studied and compared with previously reported LaAlO3-STO interface. This observation suggests a revisit to the explanation of possible origin of such conductivity beyond the polar catastrophe scenario and can be instrumental in search for novel conducting interfaces.