Effects of twins on the electronic properties of GaAs

Abstract

Generation of twin defects during the growth of semiconductor nanowires is a major concern, but their effects on electronic properties are not well understood. Here, combined quantum-mechanical and molecular-dynamics simulations reveal that the radiative decay time of an exciton increases due to twin. Furthermore, the twin-scattering contribution to electron mobility is found to be significant, in conformity with photoconductivity measurements. In addition to acting as a carrier-scattering source, twins in nanowires are found to modify the mobility by changing strain and thereby the effective mass. These effects should have profound impacts on the efficiency of nanowire-based devices.