Enhanced surface transport properties of high-quality ultrathin epitaxial Bi2Te3 films

IF 3.5 3区材料科学 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of Materials Science Pub Date : 2025-01-15 DOI:10.1007/s10853-025-10613-2

Jian Gao, Xudong Shi, Tingting Li, Zhiyu Wang, Mingze Li, Xuan P. A. Gao, Zhenhua Wang, Zhidong Zhang

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引用次数: 0

Abstract

The topological surface states (TSS) of 3D topological insulators (TI) play a crucial role in their transport. How to avoid intrinsic defects in materials and thus increase the proportion of surface states in the transport process poses a great challenge to materials scientists. In our work, high-quality epitaxial topological insulator Bi₂Te₃ ultrathin films with flat surface were prepared by pulsed laser deposition (PLD). The insulating resistivity-temperature (ρ-T) curve in Bi₂(Te_xSe_1-x)₃ films with optimal doping concentration (25–35%) shows the transport of bulk state caused by intrinsic defects which is gradually suppressed. In thinner Bi₂Te₃ films, the ρ-T curve displays a transition from negative to positive slope at higher temperatures, which is attributed to enhanced electron–electron interaction (EEI). The transition from a parabolic to a linear to a weak anti-localization (WAL) was observed in the magnetoresistance (MR) results of pure Bi₂Te₃ ultrathin films with different thicknesses. By comparing the MR of Bi₂(Te_xSe_1-x)₃ films with different Se doping concentrations, it is found that the MR of the Se-doped films and the WAL near the zero magnetic field are obvious, and the change is greatest at the optimal doping concentration. The magnetoconductivity (MC) data ΔG can be fitted well by the quantum interference model Hikami, Larkin, and Nagaoka (HLN) equation at magnetic fields as high as ± 7 T. This provides guidance for further research on how to enhance the TSS transport of 3D TIs.

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来源期刊

Journal of Materials Science 工程技术-材料科学：综合

CiteScore

7.90

自引率

4.40%

发文量

1297

审稿时长

2.4 months

期刊介绍： The Journal of Materials Science publishes reviews, full-length papers, and short Communications recording original research results on, or techniques for studying the relationship between structure, properties, and uses of materials. The subjects are seen from international and interdisciplinary perspectives covering areas including metals, ceramics, glasses, polymers, electrical materials, composite materials, fibers, nanostructured materials, nanocomposites, and biological and biomedical materials. The Journal of Materials Science is now firmly established as the leading source of primary communication for scientists investigating the structure and properties of all engineering materials.