Carrier capture time in T-shaped semiconductor quantum wires

Abstract

We investigate the capture time from quasi-two-dimensional (2D) electrons to quasi-one-dimensional electrons (1D) in T-shaped semiconductor quantum wires. Two processes are considered: longitudinal-optical-(LO)-phonon emission and quasi-elastic acoustical-phonon scattering. The quasi-1D ground state is a shallow bound state and is separated by less than one LO-phonon from the quasi-2D continuum. This enhances the LO-phonon emission process which largely dominates the capture process. The effects of the modulation of the density probability of the quasi-2D continuum lead only to a weak dependence of the capture time on the structure parameters.