Inas nanowires with surface states as building blocks for tube-like electrical sensing devices

Abstract

In this chapter, a theoretical study based on the solution of coupled Schrödinger and Poisson equations shows that the conduction band bending and the electron density in the InAs nanowires are strongly affected by the charged surface states at both low and room temperature. The electric field induced by the positively charged donor-type surface states bends the conduction band downwards and for a surface states density above 5×1012 cm-2 the Fermi level is pinned above the conduction band edge. Thus, InAs nanowires with a radius above 20 nm show significant electron density even without doping due to the donor-type surface states providing free electrons. Further, n-type doping of the nanowire can substantially flatten the conduction band and redistribute electrons over the entire cross section of the nanowire. This study provides design criteria for NW-based tube-like electrical sensing devices and field-effect transistors. Controlled Vocabulary Terms bending; conduction bands; electric sensing devices; electron density; field effect transistors; nanowires © 2013 John Wiley.