Calculated effects of interface grading in GaAs-Ga_1-xAl_xAs quantum wells

Abstract

Effects of interface grading on energy levels of electrons in GaAsGa1-xAlxAs quantum wells have been estimated using both a tight-binding formalism and an effective-mass Hamiltonian of the BenDaniel-Duke form. Graded interfaces a few atomic layers thich have only a small effect on energy levels in both schemes. Self-consistent calculations for electrons in a relatively wide (40 nm) quantum well show how the lowest levels change from those characteristic of the empty well to those characteristic of two weakly coupled heterojunctions as the electron density is increased. © 1985.