Peric N, Dursap T, Becdelievre J, Berthe M, Addad A, Romeo P Rojo, Bachelet R, Saint-Girons G, Lancry O, Legendre S, Biadala L, Penuelas J, Grandidier B
Univ. Lille, CNRS, Centrale Lille, Univ. Polytechnique Hauts-de-France, Junia-ISEN, UMR 8520 - IEMN, F-59000 Lille, France.
Institut des Nanotechnologies de Lyon-INL, UMR 5270 CNRS, Université de Lyon, Ecole Centrale de Lyon, 36 Avenue Guy de Collongue, F-69134 Ecully cedex, France.
Nanotechnology. 2022 Jun 20;33(37). doi: 10.1088/1361-6528/ac7576.
We have studied electronic transport in undoped GaAs/SrTiOcore-shell nanowires standing on their Si substrate with two-tip scanning tunneling microscopy in ultrahigh vacuum. The resistance profile along the nanowires is proportional to the tip separation with resistances per unit length of a few GΩ/m. Examination of the different transport pathways parallel to the nanowire growth axis reveals that the measured resistance is consistent with a conduction along the interfacial states at the GaAs{110} sidewalls, the 2 nm thick SrTiOshell being as much as resistive, despite oxygen deficient growth conditions. The origin of the shell resistivity is discussed in light of the nanowire analysis with transmission electron microscopy and Raman spectroscopy, providing good grounds for the use of SrTiOshells as gate insulators.
我们利用双探针扫描隧道显微镜在超高真空中研究了站立在硅衬底上的未掺杂GaAs/SrTiO核壳纳米线中的电子输运。沿着纳米线的电阻分布与探针间距成正比，单位长度电阻为几GΩ/m。对平行于纳米线生长轴的不同输运路径的研究表明，测得的电阻与沿GaAs{110}侧壁界面态的传导一致，尽管生长条件缺氧，但2nm厚的SrTiO壳层电阻很大。结合透射电子显微镜和拉曼光谱对纳米线进行分析，讨论了壳层电阻率的起源，为将SrTiO壳层用作栅极绝缘体提供了充分的依据。
