中文摘要：

通过脉冲激光沉积技术在（001）方向的La_（0.7）Sr_（0.3）Mn O_3/Sr Ti O_3上制备了厚度为500 nm的Bi_（0.9）La_（0.1）FeO_3铁电薄膜,研究了薄膜中的光伏效应。结果表明,铁电薄膜中短路光电流的方向不依赖于整流方向,但始终与极化方向相反,其大小随极化强度的增加变大,并且在净极化强度为零时短路光电流恰好为零。然而,当畴壁浓度或氧空位分布的影响足以补偿由极化所产生的效果时,短路光电流不依赖于极化方向。通过改变畴壁浓度或者氧空位分布,不改变极化方向时可以使得短路光电流的方向发生转变;通过改变氧空位的分布,极化方向改变时,光电流的方向也可以不变。我们的结果为通过改变极化方向、氧空位分布、界面势垒的高度以及电畴密度等因素来调控铁电薄膜中光伏效应具有一定的价值。

英文摘要：

Bi_（0.9）La_（0.1）FeO_3 ferroelectric films with the thickness of 500 nm were deposited on the（001） oriented La_（0.7）Sr_（0.3）Mn O_3/Sr Ti O_3 substrate using pulsed laser deposition, and the photovoltaic effect of the film was researched. The result indicates that the direction of short-circuited photocurrent is independent on the rectification direction, but it is always opposite to the polarization. The value of short-circuited photocurrent increases with polarization intensity and becomes exactly zero when the net polarization intensity is zero. However, the photocurrent direction is not depended on the polarization direction when the effect of domain wall concentration or oxygen vacancy distribution is strong enough to compensate the effect of polarization. The direction of photocurrent can be switched through changing the oxygen vacancy distribution and（or） domain wall concentration. The direction of photocurrent also can remain unchanged by altering the oxygen vacancy distribution when the polarization direction transformed. The result provides an important information for tuning ferroelectric photovoltaic effect by changing the polarization direction, oxygen vacancy distribution, interfacial potential barrier height or electric domain density.