Nonvolatile resistive switching in lead-free La2CoMnO6-based memory device

Dense and flat La2CoMnO6 films as the resistive switching functional layer were deposited on n-type Si substrates by sol-gel method. Excellent bipolar resistive switching performance was observed in the Au/La2CoMnO6/Si device for the first time. The high and low resistance states with a ratio of-105 could be maintained for more than 1.4 x 104 s and 750 cycles without significant degradation at room temperature. The bipolar resistive switching effect could be sustained within a wide temperature range of 220 K-300 K. Electrical conduction analysis indicated that the resistive switching behavior in La2CoMnO6 films was primarily controlled by space-charge-limited current mechanism which originated from the change of oxygen vacancies. Density functional theory calculations indicated that the conductive ability of La2CoMnO6 films was promoted with increasing concentration of oxygen vacancies. Moreover, it is found that the modulation of the barrier located at the Au/La2CoMnO6 interface was responsible for the resistive switching under applied bias voltages.