Reversible Resistance Switching of 2D Electron Gas at LaAlO3/SrTiO3 Heterointerface

Resistance modulation of 2D electron gas (2DEG) at oxide heterointerfaces has recently attracted extensive interests in nonvolatile memory and various sensors. Specially, ferroelectric devices based on 2DEG resistance switching at oxide heterointerfaces by ferroelectric polarization are particularly important in memory and light sensors. Herein, a nonvolatile ferroelectric memristor is reported by the 2DEG resistance change at an LaAlO3/SrTiO3 heterointerface by switching the ferroelectric polarization of a BiFeO3 layer, showing reversible two order of magnitude resistance change, the largest switching ratio in free-lead ferroelectric memristors so far. The mechanisms of the 2DEG reversible resistance switching at the LaAlO3/SrTiO3 heterointerfaces modulated by the ferroelectric polarization and light illumination are discussed. These findings demonstrate a practical approach for the nonvolatile memory and sensor applications using the 2DEG resistance switching by the ferroelectric polarization and light illumination.