Shaanxi Key Laboratory of Condensed Matter Structures and Properties, School of Science, Northwestern Polytechnical University , Xi'an 710072, China.
ACS Appl Mater Interfaces. 2017 Nov 8;9(44):39011-39017. doi: 10.1021/acsami.7b11727. Epub 2017 Oct 24.
Modulating transport behaviors of two-dimensional electron gases are of critical importance for applications of the next-generation multifunctional oxide electronics. In this study, transport behaviors of LaAlO/SrTiO heterointerfaces modified through the Ni dopant and the light irradiation have been investigated. Through the Ni dopant, the resistances increase significantly and a resistance upturn phenomenon due to the Kondo effect is observed at T < 40 K. Under a 360 nm light irradiation, the interfaces exhibit a persistent photoconductivity and a suppressed Kondo effect at low temperature due to the increased mobility measured through the photo-Hall method. Moreover, the relative changes in resistance of interfaces induced by light are increased from 800 to 6600% at T = 12 K with increasing the substitution of Ni, which is discussed by the band bending and the lattice effect due to the Ni dopant. This work paves the way for better controlling the emerging properties of complex oxide heterointerfaces and would be helpful for photoelectric device applications based on all-oxides.
调制二维电子气的输运行为对于下一代多功能氧化物电子学的应用至关重要。在本研究中，通过 Ni 掺杂和光辐照修饰了 LaAlO/SrTiO 异质界面，并研究了其输运行为。通过 Ni 掺杂，电阻显著增加，并且在 T < 40 K 时观察到由于 Kondo 效应引起的电阻上升现象。在 360nm 光辐照下，由于光霍尔法测量到的迁移率增加，界面在低温下表现出持续的光电导和抑制的 Kondo 效应。此外，随着 Ni 取代的增加，光诱导的界面电阻相对变化从 T = 12K 的 800%增加到 6600%，这可以通过能带弯曲和 Ni 掺杂引起的晶格效应来解释。这项工作为更好地控制复杂氧化物异质界面的新兴特性铺平了道路，对于基于全氧化物的光电设备应用将有所帮助。
