ELECTRONIC SUBBAND STUDIES OF A STRAINED AL0.22GA0.78AS IN0.15GA0.85AS/GAAS ONE-SIDE-MODULATION-DOPED QUANTUM-WELL/

Shubnikov-de Haas and Van der Pauw Hall effect measurements on a strai ned Al0.22Ga0.78As/In0.15Ga0.85As/GaAs one-side-modulation-doped quant um well grown by molecular beam epitaxy have been carried out to inves tigate the properties of an electron gas in a single quantum well. Tra nsmission electron microscopy measurements showed that the Al0.22Ga0.7 8As/In0.15Ga0.85As and In0.15Ga0.85As/ GaAs interfaces have no misfit dislocations. The results of the Shubnikov-de Haas measurements and th e 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 indic ate electron occupation of two subbands in the In0.15Ga0.85As single q uantum well. Electronic subband energies and wavefunctions in the In0. 15Ga0.85As quantum well were calculated by a self-consistent method ta king into account exchange-correlation effects.