Ferroelectric switched all-metallic-oxide p-n junctions

superconductor (HTSC) elec-tronics, spintronics based on the colossal magnetoresis-tance (CMR) manganites, and so on, the oxide p-n (p-I-n) junctions (oxide diodes) also are the basic devices, andhave been studied widely. One route, a hole-doped ox-ide(s), currently, the p-type CMR manganite(s) is used,which is deposited on the n-type semiconductor oxideto form the p-n junctions [1, 2, 3, 4, 5, 6]. The otherroute, the oxide insulator is used to sandwich the semi-conductor p-type oxide and semiconductor n-type oxide(orn-typepure semiconductor)topreparethe p-I-njunc-tions [7, 8, 9]. It must be noted that the semiconductorfunctional oxides are usually due to the under doping ,theoptimally doped p- and n-type oxide functional materialsare metallic phase oxides with their maximum functions.Therefore, for really developing the oxide electronics andmaking matchable oxide electronic circuits, exploiting away to prepare entire new oxide p-n junctions based onthe optimally doped metallic functional oxides is an im-perative topic. It is known that the origin of the rectify-ing function of the conventional semiconductor p-n junc-tions is the formation of the potential barrier, called thebuilt-in field V