Electronic subband studies of a strained Al 0.22Ga 0.78As/In 0.15Ga 0.85As/GaAs one-side-modulation-doped quantum well

Abstract

Shubnikov-de Haas and Van der Pauw Hall effect measurements on a strained Al 0.22Ga 0.78As/In 0.15Ga 0.85As/GaAs one-side-modulation-doped quantum well grown by molecular beam epitaxy have been carried out to investigate the properties of an electron gas in a single quantum well. Transmission electron microscopy measurements showed that the Al 0.22Ga 0.78As In 0.15Ga 0.85As and In 0.15Ga 0.85As GaAs interfaces have no misfit dislocations. The results of the Shubnikov-de Haas measurements and the observation of the quantum Hall effect at 1.5 K clearly demonstrated the existence of a two-dimensional electron gas in the quantum well, and the fast Fourier transform results for the S-dH data clearly indicate electron occupation of two subbands in the In 0.15Ga 0.85As single quantum well. Electronic subband energies and wavefunctions in the In 0.15Ga 0.85As quantum well were calculated by a self-consistent method taking into account exchange-correlation effects.