Properties and tailoring of the ubiquitous core-shell p-n junction in semiconductor nanowires by δ-doping

Abstract

The properties of the core-shell p-n junction in GaAs nanowires have been investigated via the self-consistent solution of the Poisson-Schrödinger equations in cylindrical coordinates and the effective mass approximation for doping levels between 1017-1019 cm-3 and radii ≤100 nm at 300 K. Only electrons or holes are confined in the n- or p-type core for equal core-shell thicknesses and doping levels but the shell is depleted even when a flat-band condition exists at the surface for equal core-shell volumes. In contrast, a δ-doped n-i-n-i-p-i junction has a balanced charge distribution and flat-band potential in the core and shell which is critical for the realization of high performance nanowire devices. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.