Epitaxial diodes of a half-metallic ferromagnet on an oxide semiconductor

We report on the fabrication and electrical characterization of epitaxial Schottky diodes of a half-metallic ferromagnet on an oxide semiconductor. La0.67Sr0.33MnO3 thin films are grown by pulsed laser deposition on niobium-doped SrTiO3 semiconductor substrates with two doping concentrations and a TiO2 surface termination. The current across the diodes is dominated by thermionic emission and shows high rectification and low reverse bias leakage. At room temperature, the Schottky barrier height is 0.95 eV (0.65 eV) and the ideality factor is 1.08 (1.18) for the diodes with a low (high) doped semiconductor. With decreasing temperature the Schottky barrier height decreases and the ideality factor increases.