Universality of electron mobility in LaAlO3/SrTiO3 and bulk SrTiO3

被引：14

作者：

Trier, Felix ^{[1
,5
]}

Reich, K. V. ^{[2
,3
]}

Christensen, Dennis Valbjorn ^{[1
]}

Zhang, Yu ^{[1
]}

Tuller, Harry L. ^{[4
]}

Chen, Yunzhong ^{[1
]}

Shklovskii, B. I. ^{[2
]}

Pryds, Nini ^{[1
]}

机构：

[1] Tech Univ Denmark, Dept Energy Convers & Storage, Riso Campus, DK-4000 Roskilde, Denmark

[2] Univ Minnesota, Fine Theoret Phys Inst, Minneapolis, MN 55455 USA

[3] Ioffe Inst, St Petersburg 194021, Russia

[4] MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA

[5] Univ Paris Saclay, Univ Paris Sud, Thales, Unite Mixte Phys CNRS, F-91767 Palaiseau, France

来源：

APPLIED PHYSICS LETTERS | 2017年 / 111卷 / 09期

基金：

俄罗斯科学基金会; 美国国家科学基金会;

关键词：

OXIDE INTERFACES; GASES; GROWTH; CHARGE;

D O I：

10.1063/1.5001316

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

Metallic LaAlO3/SrTiO3 (LAO/STO) interfaces attract enormous attention, but the relationship between the electron mobility and the sheet electron density, n(s), is poorly understood. Here, we derive a simple expression for the three-dimensional electron density near the interface, n(3D), as a function of n(s) and find that the mobility for LAO/STO-based interfaces depends on n(3D) in the same way as it does for bulk doped STO. It is known that undoped bulk STO is strongly compensated with N similar or equal to 5 x 10(18) cm(-3) background donors and acceptors. In intentionally doped bulk STO with a concentration of electrons n(3D) < N, background impurities determine the electron scattering. Thus, when n(3D) < N, it is natural to see in LAO/STO the same mobility as in the bulk. On the other hand, in the bulk samples with n(3D) > N, the mobility collapses because scattering happens on n(3D) intentionally introduced donors. For LAO/STO, the polar catastrophe which provides electrons is not supposed to provide an equal number of random donors and thus the mobility should be larger. The fact that the mobility is still the same implies that for the LAO/STO, the polar catastrophe model should be revisited. Published by AIP Publishing.

引用

页数：4