Alkali-metal-induced Fermi level and two dimensional electrons at cleaved InAs(110) surfaces

TL;DR

This study investigates how alkali-metal deposition on cleaved InAs(110) surfaces induces two-dimensional electron gases, analyzing Fermi level pinning and electron densities through low-temperature Hall measurements and comparing results with photoelectron spectroscopy data.

Contribution

It provides a detailed analysis of alkali-metal-induced Fermi level pinning and 2DEG formation on InAs(110) surfaces, combining experimental measurements with theoretical calculations.

Findings

Fermi level pinning occurs at specific surface donor levels.

Deposition of Cs or Na induces measurable 2DEGs.

Results align with previous photoelectron spectroscopy data.

Abstract

Low-temperature Hall measurements have been performed on two-dimensional electron gases (2DEGs) induced by deposition of Cs or Na on in situ cleaved surfaces of p-type InAs. The surface donor level, at which the Fermi energy of the 2DEG is pinned, is calculated from the observed saturation surface electron density using a surface potential determined self-consistently. The results are compared to those of previous photoelectron spectroscopy measurements.