Electrical properties of La-doped strontium titanate thin films

We report on the properties of lanthanum-doped SrTiO3 thin films grown by off-axis laser ablation on LaAlO3 and SrTiO3 substrates in oxygen partial pressures ranging from 10−8 Torr to 55 mTorr. The La/Sr doping ratio of the ablation target was 1%. The resulting films have carrier densities measured in the range of 4.7–17.5×1019 cm−3 independent of temperature from room temperature to 4 K and low-temperature mobilities as high as 130 cm2/V s. These films are much more tolerant to the presence of oxygen during growth than were similar Nb-doped films reported previously.