Rectifying behavior and magnetic tunability in heterojunctions composed of p-La0.9Ba0.1MnO3/n-Si

Heteroepitaxial p–n junctions are formed by growing a p-La0.9Ba0.1MnO3 (LOMB) layer on a n-Si substrate using conventional pulsed laser deposition. To avoid the rapid oxidation of silicon surface, an ultrathin SrTiO3 buffer layer is inserted between LBMO and Si. Such p-LBMO/n-Si heterojunctions present good rectifying characteristic in wide temperature range from 10 to 310 K. The asymmetric transport behavior is found being strong when the temperature decreases, which is understandable considering the change of band gap in LBMO films. As a typical feature of the CMR manganites is the strong dependence of their properties on magnetic fields, the magnetic response of these heterojunctions was studied. It is found that the applied magnetic field bend the I–V curves and reduce the diffusion voltage significantly. Also, a negative magnetoresistance appears in the field, demonstrating the magnetic tenability for these manganite heterojunctions.