Density functional theory study on the formation mechanism and electrical properties of two-dimensional electron gas in biaxial-strained LaGaO [Formula: see text] /BaSnO [Formula: see text] heterostructure

Yuling Li; Yuxi Huang; Xiaohua Liu; Yaqin Wang; Le Yuan

doi:10.1038/s41598-024-60893-y

Density functional theory study on the formation mechanism and electrical properties of two-dimensional electron gas in biaxial-strained LaGaO $_{3}$ /BaSnO $_{3}$ heterostructure

Sci Rep. 2024 May 4;14(1):10259. doi: 10.1038/s41598-024-60893-y.

Authors

Yuling Li¹, Yuxi Huang¹, Xiaohua Liu¹, Yaqin Wang^{2

3}, Le Yuan¹

Affiliations

¹ Key Laboratory of Fluid and Power Machinery, School of Material Science and Engineering, Xihua University, Chengdu, 610039, People's Republic of China.
² Key Laboratory of Fluid and Power Machinery, School of Material Science and Engineering, Xihua University, Chengdu, 610039, People's Republic of China. wangyqyyxf@sina.com.
³ State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054, People's Republic of China. wangyqyyxf@sina.com.

PMID: 38704471
DOI: 10.1038/s41598-024-60893-y

Abstract

The two-dimensional electron gas (2DEG) in BaSnO $_{3}$ -based heterostructure (HS) has received tremendous attention in the electronic applications because of its excellent electron migration characteristic. We modeled the n-type (LaO) $^{+}$ /(SnO $_{2}$ ) $^{0}$ interface by depositing LaGaO $_{3}$ film on the BaSnO $_{3}$ substrate and explored strain effects on the critical thickness for forming 2DEG and electrical properties of LaGaO $_{3}$ /BaSnO $_{3}$ HS system using first-principles electronic structure calculations. The results indicate that to form 2DEG in the unstrained LaGaO $_{3}$ /BaSnO $_{3}$ HS system, a minimum thickness of approximately 4 unit cells of LaGaO $_{3}$ film is necessary. An increased film thickness of LaGaO $_{3}$ is required to form the 2DEG for -3%-biaxially-strained HS system and the critical thickness is 3 unit cells for 3%-baxially-strained HS system, which is caused by the strain-induced change of the electrostatic potential in LaGaO $_{3}$ film. In addition, the biaxial strain plays an important role in tailoring the electrical properties of 2DEG in LaGaO $_{3}$ /BaSnO $_{3}$ HS syestem. The interfacial charge carrier density, electron mobility and electrical conductivity can be optimized when a moderate tensile strain is applied on the BaSnO $_{3}$ substrate in the ab-plane.

Abstract

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