Bipolar resistive switching in Cr-doped TiO_x thin films

The electric-pulse-induced resistive switching effect is studied for Ti_0.85Cr_0.15O_x (TCO) films grown on Ir—Si substrates by pulsed laser deposition. Such a TCO device exhibits bipolar switching behaviour with an electric-pulse-induced resistance ratio as large as about 1000% and threshold voltages smaller than 2 V. The resistive switching characteristics may be understood by resistance changes of a Schottky junction composed of a metal and an n-type semiconductor, and its nonvolatility is attributed to the movement of oxygen vacancies near the interface.