p-n junctions
Abstract
La0.67Sr0.33MnO3 (LSMO) films were grown on 0.7 wt% Nb-doped SrTiO3 (NSTO) single-crystal substrates by pulsed laser deposition. The crystal phase structure and surface morphology of the LSMO films were investigated by means of X-ray diffraction method and atomic force microscopy, respectively. The diode-like behavior was observed in the leakage currents of the LSMO/NSTO heterojunction, by which I- V curves were measured at room temperature. The leakage current of LSMO/NSTO heterojunction follows the space-charge-limited conduction (SCLC) model under lower forward bias. As the forward bias increases, the barrier at the LSMO/NSTO interface becomes narrower and lower, which allows electrons to go over/through the interface barrier by the conduction mechanisms of Schottky emission and interface-limited Fowler-Nordheim tunneling, respectively. Under the same backward bias, the leakage current still undergoes the Ohmic law region according to the SCLC model, which is due to the drift currents of holes in the LSMO films and electrons in the NSTO substrates.
- Publication:
-
Applied Physics A: Materials Science & Processing
- Pub Date:
- September 2014
- DOI:
- 10.1007/s00339-014-8348-9
- Bibcode:
- 2014ApPhA.116.1885P