铁酸铋薄膜的阻变效应和导电机制

Resistive Switching Effect and Conduction Mechanism of BiFeO_3 Thin Films

针对脉冲激光沉积法制备的铁酸铋薄膜展开研究,利用电流–电压(I–V)特性曲线表征样品的阻变现象,对样品施加不同极性、大小的电压,其I–V曲线呈现出不同高低阻值的变化。通过对I–V曲线拟合,发现样品的导电机制符合空间电荷限制电流。结合正向电压下从高阻到低阻的转变,负向电压下从低阻到高阻的转变规律,验证样品的阻变效应符合陷阱能级的填充和脱陷,即陷阱能级的填充程度不同导致电极与铁酸铋界面势垒高度不同从而导致薄膜阻值的变化。

The resistive switching behavior of BiFeO3 thin film prepared via pulsed laser deposition was investigated. The current-voltage （I-V） curves were measured at different voltages. The resistance changes from high value to low value at a positive voltage, and the resistance changes from low value to high value at a negative voltage. The space charge limited conduction mechanism was analyzed through the fitting of the I-V curves. The resistive effect is attributed to the electric filed induced carrier trapping and detrapping, which results in the variation of the Schottky barrier height at the interface between the film and the electrode.