Spatially resolved electrical properties of InAs/InP quantum dots and wires

Abstract

In this paper the electrical properties of InAs/InP nanostructures (wires and dots) were investigated using Kelvin probe electrostatic force microscopy and conductive atomic force microscopy techniques. Surface potential measurements were strongly affected by the presence of the thin InAs film at the top surface of the undoped InP buffer layer. These results and the electrical images suggest the suppression of the surface depletion region due to electron accumulation in InAs wires and dots. I–V spectroscopy shows the formation of a Schottky-type junction between the metal-coated Si tip and the semiconductor surface exposed to air. Larger conductances and different threshold voltages for current onset for the two types of nanostructure analysed here can be related to the particular electronic structure of InAs wires and dots.