Ferroelectric Schottky Diode

A Schottky contact consisting of a semiconducting ferroelectric material and a high work function metal shows a bistable conduction characteristic. An on/off ratio of about 2 orders of magnitude was obtained in a structure consisting of a 0.2 μm ferroelectric PbTi${\mathrm{O}}_3$ film, a Au Schottky contact, and a ${\mathrm{La}}_{0.5}$${\mathrm{Sr}}_{0.5}$Co${\mathrm{O}}_3$ Ohmic bottom electrode. The observations are explained by a model in which the depletion width of the ferroelectric Schottky diode is determined by the polarization dependence of the internal electric field at the metal-ferroelectric interface.