Interfacial charge and strain are two coupling effects in semiconductor/ferroelectric epitaxial heterostructures, which are pivotal for use in tailoring functionalities in devices. In this work, La0.04Ba0.96SnO3/0.7Pb(Mg1/3Nb2/3)O3–0.3PbTiO3 heterostructures with varying film thicknesses were prepared in order to understand both charge and strain's contributions to the electric-field induced resistance change. The relative resistance change to the lattice strain remains almost unchanged in those thicker films, while increases a little bit in those thinner films. This slight increase is related to the substrate constraint near the interface and follows Freund's strain relaxation model during the dynamic strain induced by the piezoelectric switch. A depletion layer model was also established to simulate the electroresistance variation from the interfacial charge effect. The depletion layer involves an equilibrium between capture and release of electrons by the acceptor-like defects near the interface region. The resistance change vs electric field evolves from a butterfly-like shape to a square-like when decreasing the film thickness, due to the joint effect of strain and interfacial polarization screening charge. This study provides an insight into understanding heteroepitaxial coupling and exploring their potential applications in oxide electronic devices.

中文翻译：

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铁电门控下镧掺杂锡酸钡薄膜的界面电荷和应变效应

界面电荷和应变是半导体/铁电外延异质结构中的两种耦合效应，它们对于定制器件功能至关重要。在这项工作中，为了了解电荷和应变对电场引起的电阻变化的贡献，制备了具有不同薄膜厚度的 La0.04Ba0.96SnO3/0.7Pb(Mg1/3Nb2/3)O3–0.3PbTiO3 异质结构。在较厚的薄膜中，晶格应变的相对电阻变化几乎保持不变，而在较薄的薄膜中略有增加。这种轻微的增加与界面附近的衬底约束有关，并且在压电开关引起的动态应变期间遵循弗氏应变松弛模型。还建立了耗尽层模型来模拟界面电荷效应引起的电阻变化。耗尽层涉及界面区域附近的受体样缺陷捕获和释放电子之间的平衡。由于应变和界面极化屏蔽电荷的共同作用，当薄膜厚度减小时，电阻随电场变化从蝴蝶状演变为方形。这项研究为理解异质外延耦合和探索它们在氧化物电子器件中的潜在应用提供了见解。由于应变和界面极化屏蔽电荷的共同作用，当薄膜厚度减小时，电阻随电场变化从蝴蝶状演变为方形。这项研究为理解异质外延耦合和探索它们在氧化物电子器件中的潜在应用提供了见解。由于应变和界面极化屏蔽电荷的共同作用，当薄膜厚度减小时，电阻随电场变化从蝴蝶状演变为方形。这项研究为理解异质外延耦合和探索它们在氧化物电子器件中的潜在应用提供了见解。