We successfully prepare BiFe(1-x)PdxO3 (BFPxO) thin films (i.e. ferroelectric bismuth ferrite with Fe-site partially substituted by palladium ions) as well as BFPxO/NiO heterostructure though sol-gel method. We try to figure out the two aspects of problems in this work. On one hand, crucial roles that Pd doping plays in optoelectronic characteristics of BFPxO are elucidated. The relationships among Pd valence, lattice distortion and optoelectronic performance of BFPxO are built. We confirm that Pd doping can minimize the response time constant of BiFe(1-x)PdxO3 below 10 ms; meanwhile, the detectivity of BFPO/NiO heterostructure can reach up to ca. 109 Jones. On the other hand, open-circuit voltage decay (OCVD), a kind of transient measurement technique, is adopted to gain an insight into distinct decay stages existing in BFPxO. The abnormal transient phenomenon with ‘overlong’ relaxation time higher than 10 s is probably contributed by depolarization process of BFPxO. Consequently, we reveal hidden photoactive natures of ferroic perovskite oxides, which may derive from the synergic kinetics of polarization/depolarization associating to ferroelectric domains and particularly be triggered by the noble metal element doping.

中文翻译：

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铁电 Pd 掺杂铋铁氧体光活性薄膜中去极化的协同动力学解耦


我们通过溶胶-凝胶法成功制备了 BiFe（1-x）PdxO3 （BFPxO） 薄膜（即铁电铋铁氧体，Fe 位部分被钯离子取代）以及 BFPxO/NiO 异质结构。我们试图弄清楚这项工作中问题的两个方面。一方面，阐明了 Pd 掺杂在 BFPxO 的光电特性中起的关键作用。建立了 BFPxO 的 Pd 价、晶格畸变和光电性能之间的关系。我们证实 Pd 掺杂可以将 BiFe（1-x）PdxO3 的响应时间常数最小化到 10 ms 以下;同时，BFPO/NiO 异质结构的探测率可高达 109 Jones。另一方面，采用开路电压衰减 （OCVD） 是一种瞬态测量技术，以深入了解 BFPxO 中存在的不同衰减阶段。“过长”弛豫时间大于 10 s 的异常瞬态现象可能是由 BFPxO 的去极化过程引起的。因此，我们揭示了铁钙钛矿氧化物隐藏的光活性性质，这可能源于与铁电畴相关的极化/去极化的协同动力学，特别是由贵金属元素掺杂触发。