Abundant photoelectronic behaviors of La_0.67Sr_0.33MnO₃/Nb:SrTiO₃ junctions

Temperature dependence on rectifying and photoelectronic properties of La_0.67Sr_0.33MnO₃/Nb:SrTiO₃ (LSMO/STON) junctions with the thickness values of LSMO film varying from 1 nm to 54 nm are systematically studied. As shown experimentally, the junctions exhibit good rectifying properties. The significant differences in photoemission property among the LSMO/STON junctions are observed. For the junction in a thicker LSMO film, the photocurrent shows a monotonic growth when temperature decreases from 300 K to 13 K. While for the junction in an ultrathin LSMO film, the behaviors of photocurrent are more complicated. The photocurrent increases rapidly to a maximum and then smoothly decreases with the decrease of temperature. The unusual phenomenon can be elucidated by the diffusion and recombination model of the photocarrier.