Optimized transport properties of LaAlO3/SrTiO3 heterointerfaces by variation of pulsed laser fluence

We show the influence of pulsed laser deposition fluence on the transport properties of the LaAlO3/SrTiO3 (LAO/STO) heterointerface. Structural characterization by x-ray diffraction and medium energy ion spectrometry enables us to deduce that the electronic behaviour is extremely sensitive to the stoichiometry of the LAO layer as well as the structural quality of the STO surface. An optimum balance of these two quantities is demonstrated for an intermediate laser fluence.