Diode and photocurrent effect in ferroelectric BaTiO3-δ

The leakage current has been regarded as one of the major problems in ferroelectric memories. However, recent studies on the unidirectional electric transport through a ferroelectric single crystal and the giant tunnel electroresistance in ferroelectric tunnel junctions suggest a possibility to utilize this undesirable leakage current. Here, we present the diodelike transport and the significantly enhanced photocurrent effects in oxygen-deficient BaTiO3-delta single crystals, which are mainly dependent on the direction of ferroelectric polarization. Diode effects in the carrier doped conventional ferroelectrics may suggest an alternative way for the nondestructive readout of polarization states in common ferroelectric memories. (C) 2011 American Institute of Physics. [doi:10.1063/1.3569619]