A comparison study of electronical and photoelectrical properties of electron gases at (100), (110) and (111) LaAlO3/SrTiO3 interfaces
A comparison study of electronical and photoelectrical properties of electron gases at (100), (110) and (111) LaAlO3/SrTiO3 interfaces
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(100)、(110)和(111)LaAlO3/SrTiO3界面电子气电子和光电性质的比较研究
DOI：
10.1088/1361-6463/ab5c66
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Gao J.
中科院分区：
文献类型：
--
作者：
Liu G. Z.;Chen J. Q.;Jiang Y. C.;Zhao R.;Qiu J.;Gao J.
（100）、（110）和（111）LaAlO 3/SrTiO 3（LAO/STO）界面具有相似的高迁移率导电特性。在这里，我们比较了电子气体在三个接口的电子输运和光电导性能，考虑到它们在界面上的不同极性连续性和晶体学对称性。用激光分子束外延技术在STO（100）、（110）和（111）衬底上生长了LAO外延薄膜。界面处的电子气均表现出金属性，面载流子密度接近（1013 ~ 1014 cm-2），其中（100）界面处的电子气迁移率最高，在70 K以下比（111）界面处的电子气迁移率高近一个数量级。在较低温度下，所有的电子气都对可见光有明显的光电响应。光辅助霍尔测量表明，在三个接口的电子气的光电导明显不同的机制。我们的结果可以帮助理解的高迁移率的电子气体在氧化物界面，这将有助于优化器件应用的电子性能。
(1 0 0),(1 1 0) and (1 1 1) LaAlO 3/SrTiO 3 (LAO/STO) interfaces show similar high mobility conduction. Here, we compare electronic transport and photoconductivity properties of electron gases at the three interfaces, considering their different polar continuity at the interface and the crystallographic symmetry. Epitaxial LAO films were grown on STO (1 0 0),(1 1 0) and (1 1 1) substrates by laser molecular beam epitaxy. All the electron gases at the interfaces exhibit metallic behaviors with close sheet carrier density (10 13–10 14 cm− 2), the electron gas at (1 0 0) interface presents the highest mobility, which is almost one order of magnitude higher than that at (1 1 1) interface below 70 K. At lower temperatures, all the electron gases show obvious photoelectrical response to visible light illumination. Light-assisted Hall measurements indicate distinctly different mechanisms for the photoconductivity of electron gases at the three interfaces. Our results can assist the understanding of the high mobility of electron gases at oxide interfaces, which will be helpful to optimize the electronic properties for device applications.