Electrical anisotropy of heteroepitaxial InSb/GaAs layers

TL;DR

This study investigates the electrical anisotropy in heteroepitaxial InSb/GaAs layers, revealing direction-dependent electron transport influenced by nanoclusters and interface defects, with implications for anisotropic electronic device design.

Contribution

The paper uncovers the origin of low-field electrical anisotropy in InSb/GaAs layers, highlighting the roles of nanoclusters and interface defects, which was not previously understood.

Findings

Strong anisotropy of electron transport at low magnetic fields.

Electrical transport in the bulk layer is isotropic.

Inhomogeneous distribution of In nanoclusters affects anisotropy.

Abstract

We report on study of electrical and structural properties of InSb/GaAs(001) heteroepitaxial layers in [110] and [1-10] crystallographic directions. Strong anisotropy of electron transport parameters measured at a low magnetic field has been found, whereas the electrical transport through the InSb bulk layer studied by Shubnikov-de Haas oscillations is shown to be independent of the crystallographic directions. The low-field electrical anisotropy of the InSb films appears to be governed by two competitive anisotropic effects: influence of spontaneously formed In nanoclusters inhomogeneously distributed within the InSb layers and conductivity through the near-interface layer with high anisotropic density of extended defects.