The self-polarization of ferroelectric thin films plays a crucial role in simplifying the fabrication process of ferroelectric photovoltaic (FE-PV) devices, however, achieving stable self-polarization of thin films remains a challenge. Here, we demonstrate that FE-PV effects are obtained in both BiFeO₃ and A²⁺–Zr⁴⁺ (A = Ca, Sr, Ba) co-doped BiFeO₃ films, the as-fabricated films without artificial polarization, because self-polarizations exist in the films. Significantly, large FE-PV effects and high-temperature stability are simultaneously achieved. Self-polarization is enhanced by the rhombohedral to monoclinic phase transition, resulting in a large photovoltaic effect in the Bi_0.97Ba_0.03Fe_0.97Zr_0.03O₃ film under 450 nm illumination, and the photocurrent density (J_SC) and open circuit voltage (V_OC) are 0.65 mA cm⁻² and 0.39 V, respectively. The J_SC and V_OC of Bi_0.97Ba_0.03Fe_0.97Zr_0.03O₃ are 94.9% and 90.1% after 373 K heat treatment, respectively. This work provides a simple method for improving the FE-PV performance and temperature stability in ferroelectric films with self-polarization.

中文翻译：

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A2+–Zr4+（A = Ca、Sr、Ba）共掺杂 BiFeO3 薄膜具有自极化的高度稳定的光伏效应

铁电薄膜的自极化在简化铁电光伏（FE-PV）器件的制造过程中起着至关重要的作用，然而，实现薄膜稳定的自极化仍然是一个挑战。在这里，我们证明了 BiFeO ₃和 A ²⁺ –Zr ⁴⁺ (A = Ca, Sr, Ba) 共掺杂 BiFeO ₃薄膜都获得了 FE-PV 效应，这些薄膜没有人工极化，因为自- 电影中存在两极分化。值得注意的是，同时实现了大的 FE-PV 效应和高温稳定性。菱面体到单斜相的转变增强了自极化，导致 Bi _0.97 Ba _0.03 Fe _0.97 Zr _0.03 O ₃薄膜在 450 nm 光照下产生较大的光伏效应，光电流密度 ( J _SC ) 和开路电压 ( V _OC )分别为0.65mA cm ^-2和0.39V。Bi _0.97 Ba _0.03 Fe _0.97 Zr _0.03 O ₃经373 K热处理后的J SC 和V OC 分别为94.9 %和90.1 _{% 。}这项工作为提高自极化铁电薄膜的 FE-PV 性能和温度稳定性提供了一种简单的方法。