GaAs substrate orientation dependence of resonant quasi-level lifetime in 2D–2D InGaAs/GaAs resonant tunneling devices

Abstract

Resonant quasi-level lifetime of the lowest quasi-bound state localized within the quantum well region of a InGaAs/GaAs double barrier resonant tunneling structure have been analytically calculated for three different GaAs substrate orientations such as (0 0 1), (3 1 1)A and (1 1 1)A. The calculation is based on the solution of the time-independent Schrödinger equation and takes into account the effective mass changes between the well and barrier materials. A significant dependence of the ground state energy and its associated lifetime on the effective masses of the well and barrier layers, indium concentration in the well In x Ga 1− x As material, which is associated to the barrier height, and GaAs substrate orientation has been observed. We believe that the structure grown on GaAs (1 1 1)A substrate is more useful for developing new resonant tunneling two-dimensional (2D) devices. Finally, the coupling effect between transverse and longitudinal wave vector has also been investigated. With increasing the transverse wave vector the lowest energy and its associated lifetime decrease and this for the different GaAs substrate orientations.